Hello Autopians. Welcome to another edition of Ask an Engineer. Let’s start off this week with a question from Pieter about why his car was only available with 20-inch wheels, then we’ll chat about whether crossovers are tougher than cars and about the AE86 Toyota’s handling.
Pieter lives in Belgium and he has got himself a very nice new Renault Grand Scenic as a company car. It’s not a car he would necessarily have chosen himself but a free car is a free car after all. His question relates to the tires, which are P195/55R20. Apparently the new Scenic comes only with this tire size regardless of trim level and he thought that was odd. He also wondered why his car might have been equipped with steel wheels instead of aluminum alloys and what difference that would have made.
Sticking With Your OEM Tires, Some Notes About Wheel Sizes
Well, Pieter, I too find the choice of 20” wheels across the board odd, but there could be a very good reason for this. I can’t look into the minds of the engineers and product planners at Renault but one reason to have a single tire size is that tire development is expensive and time consuming. If you can release a new vehicle with the same tire on all trim levels it saves a lot of time and money during development. A lot of effort is put into making sure the tires a car is sold with perform at the high levels a manufacturer specifies. This process can take over a year to complete and requires the tire manufacturer to make several “submissions” to the car company.
In each submission, the tire company will provide several hundred tires with different types of construction and rubber compounds. The constructions may vary in the way the steel and nylon belts are oriented, or what rubber compounds are used in the tread blocks. Each design will behave differently and the vehicle development engineers will then spend several weeks testing each of the tires to see which one works the best in the car. They will test each tire for cornering, stopping, and acceleration performance in dry and wet conditions. They will test the amount of noise a tire makes over various types of road surfaces. They will see how well the tire communicates road conditions through the steering system. Does the tire wander over minor road imperfections? Is it sensitive to ruts in the road? They may also test it on special machines to get an estimate of tire life.
Stick With OEM Rubber
All this can take several months to complete and it will usually happen about three times, with each successive submission refining the tire construction until hopefully by the third submission there is at least one construction that meets the targets set by the company for that particular vehicle. These targets, as well as many other vehicle targets, like cost, weight, fuel economy, vehicle size, etc. are set very early in a vehicle program to meet the expectations of the expected customer. The overall vehicle targets then get broken down into targets for each individual system, including the suspension and tires. Often the targets are based on vehicles made by the company’s competition, and also by doing a bit of guesswork on how the competition’s future products might improve — a process called “futuring.” You have to make some assumptions about how everyone else’s products are going to get better in the years it takes to bring a new car to market and make sure your product is as good or better than that. You don’t want to get into a situation where your new car is just as good as what your competition had four years earlier.
Once the engineers find a tire submission that meets (or even exceeds) the vehicle targets, that submission will be released for production. Since so much work has gone into choosing the right tire construction for a particular car, it is almost always advisable to replace your car’s tires with the same ones it came with. Round and black is not sufficient. All tires are absolutely NOT the same and choosing a non-OEM specified tire can have significant effects on the ride and handling of your car. It can also have a very strong effect on steering feel.
The tuning of the tire and the tuning of the steering system go hand-in-hand, as the rubber plays a big role in communicating the steering feel the manufacturer wants. That great steering feel and handling confidence your BMW 3 Series has can quickly disappear if you put some generic aftermarket tire on it. More importantly though, if the replacement tires don’t have the same amount of traction as the OEM tires, you could increase your stopping distances and hurt braking performance. Replace your car’s tires with the same brand and model it came with and you will likely be much happier in the long run.
Upselling
Now let’s get back to Pieter. The thing I find odd about the choice of a single tire size is that auto companies like to make money. Preferably lots of money. And one way to do this is to get your customers to buy extra things for their car. It’s called up-selling and one of the best up-selling items is wheels. Sell a base car with 18” dull wheels and your customers will spend thousands on optional 19” and 20” wheels because they just look better. If all your cars come with 20” wheels the look of the optional wheels is not nearly as different from the base wheels as it could be. Most manufacturers have calculated that the expense of the added tire development is more than offset by the profits from selling optional wheels and tires. Renault clearly felt differently in this case.
What Renault HAS done here is offer a steel wheel as base and have an optional aluminum alloy wheel. Steel wheels are cheap to make so they help keep the base vehicle cost down but they have significant aesthetic limitations. That’s why most steel wheels come with hubcaps that make them look like alloy wheels. Hubcaps can fall off though, and they can crack and discolor, ultimately tending to look like cheap versions of the real thing. Steelies are also less stiff than aluminum wheels, which is bad for handling — perhaps not an issue for a Renault Grand Scenic, but it might be for some other cars.
So there you have it, Pieter. Enjoy your new free Grand Scenic. As they say, “drive the wheels off it”! En tot ziens.
Crossover Versus Car: Which Is Tougher?
Andrew P. asked a question regarding the “rugged” look of many crossovers and if this actually represents additional capacity in terms of durability versus the regular cars many of them are based on. Well, Andrew, the answer is “it depends.” It depends on the manufacturer and on the vehicle. Some manufacturers do use different durability testing cycles for their crossovers and some don’t. At one of the OEMs I worked for, SUVs, especially the large ones, had a durability test that was a hybrid between cars and trucks. It meant they were tougher than cars but not as tough as trucks. In other cases, though, there was a recognition that the crossover would see no more than mall duty and there was no need to build in the extra weight and cost required to meet a higher durability standard. It really depended on who the target customers were.
Where these vehicles really benefit from a durability standpoint is with their tires. The first line of defense against potholes and other road impacts is the tire, and the larger the tire, the better it is at absorbing those impacts and at protecting the rest of the car. The part of the tire size that matters here is the sidewall height since this is the rubber that gets deformed when you hit a pothole or other bump in the road. It’s very easy to figure out how much sidewall you have by looking at the tire size numbers. Take the first number in the tire size and multiply by the second number and then divide by 100. For example, a P225/50R19 tire will have a sidewall height equal to 225 X 50 / 100 = 112.5 mm.
Now take the 2022 Toyota Camry, which comes with P215/55R17 tires in base trim. That tire has a sidewall of 215 x 55 / 100 = 118.25 mm. The same year Highlander has a base tire of P235/65R18 which has a sidewall height equal to 235 X 65 / 100 = 152.75 mm. That extra 34.5 mm represents a significant extra cushion that the Highlander has before the edge of that pothole hits the rim and does some serious damage. It means that the Highlander tire will protect the rest of the car much better than the Camry tire driving over the same road. That’s not to say that the Camry tire will do a poor job. 118 mm is still more than enough to protect the car on most roads. It just means that it will take a much bigger impact to damage the Highlander than the Camry.
Why Can The Toyota AE86 Out-Handle The Honda Accord?
Jonathan asked me a question about the AE86 Toyota which has what appears to have a very basic suspension setup — MacPherson strut front and live axle rear, while the same era Honda Accord had double wishbones. The AE86 is by many considered to be a much better handling car than the Honda and Jonathan wonders why that might be given the difference in technology between the cars.
Well, Jonathan, what you are seeing is there is more to car ride and handling than just suspension choice. The AE86 may have had a basic suspension but it was designed from the beginning as a rear wheel drive (RWD) car while the Honda was always meant to be front wheel drive (FWD). Designing a FWD car means you make vehicle level decisions that favor a front heavy car. The heavy engine and transmission are all in front with the majority of the engine ahead of the front wheels. Since the transmission ends up slightly behind the engine and the front wheels must be inline with the output of the transmission, they end up further rearward. That’s why FWD cars often have so much front overhang. All this means a weight distribution around 60% front, or worse. That does not favor a well handling car. The AE86 on the other hand could push the front wheels forward because they weren’t tied to the transmission. The weight of the engine would be placed further rearward and the transmission was behind that. All that meant that the AE86 only carried 53.5% of its weight in the front. That’s a big difference and will definitely be felt in the handling of the car regardless of how sophisticated the suspension is.
Well that’s it for this week. Please keep those questions coming to askanengineer@autopian.com and I’ll do my best to keep this discussion lively and informative.
Ya this whole OEM tire being the best is very case specific and I’d wager incorrect in most. A shining example was my 05 Mini Cooper S. Factory 17″ run flats. Super stiff ride and SO heavy. The only reason for the OEM tires was styling and no room for a spare. Switched to 15″ summer performance tires and a can of fix flat. That dropped 100lbs off the car, improved ride and grip greatly. It was especially more snappy from a stop. Also got a small bump in fuel economy.
So I’m wondering about the tires on the BMW i3, which are famously tall and skinny: 155/70-19 front, 175/60-19 rear.
Clearly this choice was made in pursuit of efficiency, but notably, aside from knee-jerk reactions to the skinny tires, there are few complaints about the car’s handling. A long narrow contact patch will have other advantages on wet surfaces, so if this approach has been successful for efficiency without serious handling compromises, why hasn’t it been more widely adopted? Even BMW isn’t using it on its newer EVs.
Well, hadda happen sooner or later. The 1st bad advice of the new website?
You can’t POSSIBLY believe that an OEM is looking for the absolute BEST tire for their high-production SUV… they want the CHEAPEST tire that will meet some minimum standard. If I am willing to pay $20 a tire more, I guarantee I can do better than the accountants.
Hard to find 5.60-13 tyres locally.. Camac BC110 are the only blackwalls that I have found in that size but they are a bit pricey. Though I might be better off with some decent Michelin radials anyhow.
This should be split into 3 separate articles.
Can you add some AE86 vs Accord cgh, roll couple and tire load to the FWD vs RWD? There are so many examples of good handling fwd and I’ll handling rwd vehicles left unexplained by your post.
OEM Rubber being a must has to be dependent on the type of high performance car they’re on, bit bread and butter cars. I have a 2012 Chrysler 200 that had 2 different wheel options, 17″ and those had H-rated (130mph) tires sized at 225/55R17, while the cars like mine that had 18’s that came with T Rated (118mph) 225/50R18 Goodyear Eagle LS2 and all were limited to 120mph. Now, to me anyway, the problem comes with what’s under the hood. If you had the standard rental spec 170hp 2.4 and 4 speed auto, the LS2’s might be passable (I wouldn’t hold my breath though), bump it up to the Touring like mine or the Limited that had the 6 speed auto would be less so, then there’s the cars like mine, that has the 283hp 3.6l and 6 speed auto (same as the Grand Caravan, Town and Country, and Ram Promaster) and they were pretty much worthless unless round and black were the only criteria. If I tried to have “fun” with the car, the seemed to squirm unless it was under hard acceleration, then it was wheel spin city to go with the torque steer (which I swear the traction control made worse some how?!) and it was surprisingly easy to trip the stability control into action I’ve run all season Z rated BFG’s and V rated Firestones (also A/S) in 235/50R18 on the factory rims and swear these and the matching Avengers should have had something more like I’ve run from the factory, even if still limited to 120mph.
My Mustang required H-Rated tires as well. While I totally understand the reasoning behind it, I never once went faster than 85mph in the twelve years I owned the car. It always seemed like a case of overengineering to me, at least in my case.
Well, it seems like I’m late to the party, but I’ll cast another vote for “what the heck are you smoking if you think I want the OEM tires?!” Your thesis isn’t incorrect; the engineers optimized the car with a certain set of tires. But I think you assign WAY too much importance to that.
First, you list a bunch of constraints the manufacturer optimizes for. It’s been well-covered in the comments already that maybe I don’t agree with the manufacturer’s take on those constraints. Maybe I bought an appliance car for practicality but still want to sacrifice some of my fuel economy for better grip in some situation or another. Even if they all agree with the compromises in principle, buyers in Fargo, Seattle, and Dallas will each have VERY different traction requirements throughout the seasons. Unless the engineering team has done their compromise analysis separately for each region and shipped more than one OEM tire, undermining some of your argument in the first place, then I absolutely do not believe that the factory rubber is the best possible choice for all three buyers.
Second, you mention the engineering team “futuring”. That is, they’re already guessing about characteristics by the time the car reaches market. Hopefully they’re good at that, and their guess is correct on day 1. But why should I think their guess is still correct several years later when I need tires, to say nothing of the car’s fourth or fifth set of rubber?
Finally, you seemingly allude to cheap tires when you say “Round and black is not sufficient. All tires are absolutely NOT the same.” You get no argument here; . But there seems to be an assumption baked into the rest of the article that OEM tires are the pinnacle of tire tech, rather than the delicate compromise you otherwise describe them as. But, uhh, you know crap like Linglong and Kenda aren’t the only non-OEM choice out there, right? My Mustang came with Goodyear Eagle F1 all-seasons. I’m sure a lot of thought went into that choice, and they’re actually not bad. But surely you can understand why I might put some Pilot Sport summer rubber on as a personal choice, as long as I understand I can’t use them in the winter.
I like your content and hope we can continue to see an engineer’s view into some of these things… But man, you can be an engineer AND a car enthusiast. You don’t have to wear the corporate polo and toe the company line here.
I bet if you asked 100 suspension engineers this question, many of them would answer the same way as Huibert did. I don’t think he’s toeing any company line, he’s just IN REAL DEEP. A true enginerd, and we love him for it!
(I myself am throwing some cheap but nice, name-brand junkyard tires on my old Jeeps. Psst. Don’t tell Huibert!).
David, my man, have I mentioned that one of the attributes I like best about you is “currently in one piece”? Please take care on those cars!
I respect the engineering opinion that replacing the tire the team selected will get you back to targets set by the team. However, I don’t think that the targets set by that team are the right blend of tradeoffs for everyone. Remembering that a team may be constrained by costs, manufacture, volumes or any number of factors the consumer may not be I don’t see any reason to stick with OE unless its a very specific tire such as what Porsche does.
I’ve also been extremely and reliably disappointed with the OE tire – mainly the life. They wear out like they were made of cheese.
I agree.
I started my nearly 40 decade engineering career in automotive. First for a tire manufacturer and then a Tier 1 automotive fuel systems supplier.
Tires are ALWAYS a compromise. And what the car manufacturers prioritize is not always a good match for what I prioritize. They need to worry about CAFE mpg, cost, all-season balanced performance, decent handling in a wide variety of conditions, etc. I have lived/worked in Southwest Florida for 7 years. My priorities are different than they were in CT, Cincy, Chicago, Charlotte. The OE Goodyear LRR tires on my former ’13 Volt were clearly optimized for efficiency and stretching the teeny battery’s range. And they were reasonably quiet. However, they were flat out terrifying in the Florida rains, both for hydroplaning, cornering and braking. And for good measure, wore quickly and trammeled like hell on any highway grooves.
Some tire/car combos were pretty well optimized (my former ’03 Mini, ’14 Boxster, and ’21 Volvo XC40 Scorpions) come to mind) and performed well. In virtually every other application including sports cars, sedans, trucks and SUV’s, I’ve found better wear, handling, braking, hydroplaning, wet braking/cornering from carefully selected high quality aftermarket tires. Usually noise as well. I may have prioritized all-weather performance in Chicago, but in Florida, it’s about wet and dry traction in relatively warm weather. And because my commute is 130mi/day, fuel economy and long wear is high on my list. It’s just not possible for an OEM to work with a tire manufacturer to make one tire the best for everyone’s driving style, regardless of whether they live in Bemidji MN, Phoenix, Florida, etc.
Another difference between me and an automaker – I’m ready and willing to spend a few more $$ to get the right set of compromises for myself.
Goodyear Assurance FuelMax? Had those on my Cruze Eco. Agreed on all your points about them. That said, they did last a while and were acceptable in dry weather.
I won’t put anything else on our Cruze Diesel. They’re plenty fine in dry and wet and damn efficient.
That said: they only see service in spring/summer/fall. No way are we running those in Michigan in winter.
Counterpoint: The OEM Scorpions on my ’18 XC90 were horrendous – loud, slippery and poor wear. Switched to Defender LTXs and couldn’t be happier. I’ve never found an OEM tire where there was not a better equivalently-priced alternative.
Funny you mention the Mini. I had an 05 and the OEM tire choice was awful. I guess the tires were fine for what they were. It was the size choice that was the problem. Mine came with 17″ run flats. Switched to 15″ rims and a can of fix a flat. dropped 100lbs of the car. Grip was better, ride was better, fuel economy was better, acceleration was better. The 17″ were purely a styling choice.
The Goodyear Fuelmax on my ’12 Volt were dry-rotted and cracking their sidewalls by year 4. The Michelin Energy Savers on my ’17 Volt were nearly treadless by 25k miles. Volt OEM tires are very, very bad.
Yeah, it really depends on the driver. Your average Volt driver wants economy; I and many others on r/volt want something grippier than LRRs. “Those saved cents on LRRs add up, but it won’t add up to enough to fix your car when it breaks traction too early.”
Agree. The author’s premise is fairly simplistic and operates with the assumption that it is not possible to buy tires that are better for the user than those which came on the car from the factory. It’s kinda hogwash, actually, for all the reasons you state in your comment above and more.
I just went down a smallish rabbit hole to see if it was even possible to go back to OEM tires on one of my cars – a 1971 MGB GT. I found what the original size was, 165R14 (back before they included the aspect ratio in the size; these were about a 78 from the measurements I found), but no info whatsoever on who British Leyland would have tapped as a t(y)re source. Avon, I guess, or Michelin?
Since those old sizes aren’t available any more except from places like Coker, where they cost an arm and a leg, the typical recommended replacement size is 175/70R14, just a little wider and lower-profile than the original, but roughly the same diameter. My car currently wears 175/65R14, which I guess explains why my speedometer is off and I have crappy ground clearance. They were installed by the previous owner right before I bought it, probably because nobody stocks 70-series tires any more. But now I know what to order when they age out in a couple of years.
At least I don’t have wire wheels, then I’d have to deal with tubes…
As a fellow LBC owner, 1979 Triumph Spitfire. The aspect ratio on your OEM 165SR14 is 82%. So you are looking to go to 195/70R14 to get close.
My stock tires were 155SR13–>175/70R13.
The challenge is smaller rim sizes and decent performance rubber vs economy or trailer tires. My challenge is also fender clearance if the width gets too large.
Good luck
Discount Tire has a Falken Pro Touring A/S in 185/70R14 that sounds like it’s be a good fit for your use. It’s a well-rounded all season and the triumph has low enough power that it won’t destroy them. I run this exact tire (in the same size) on my BMW E30 (stock size is 195/65R14, which has crappy options, or one nice option that’s way too proud of itself for the performance).
Avon should be a good tire for the car I think. TVR (if they ever make the Griffith) used Avon as their supplier when the car was still being shown around.
I’ve had 5 brand new cars / trucks over the last 20 years. The tires on those new vehicles each lasted about 30k miles before needing to be replaced. When I replaced them with EXACTLY the same tires, those tires came with 60k warranties. Why are tires form the manufacturer on brand new cars so shitty?
Maybe it’s like the old HP “starter” ink cartridges that were only half full?
Nothing “old” about that. Its still pretty common for printers to come with less ink that the replacement packs.
Maybe it’s like motorcycle tires.
https://www.youtube.com/watch?v=Tv97i_-V7hA
BTW I find car or motorcycle manufacturers choices rarely target me as a user, but rather price and low rolling resistance for good fuel mileage.
Mileage is hardly a measure of how good a tire is. A tire that lasts 100k miles and puts you in a ditch at the thought of rain worthless.
My buddy and I have had this same question, and here’s his theory: auto manufacturers don’t want to be storing millions of tires in some warehouse, so they receive the tires through just-in-time shipping. This means that the time between manufacture and putting the tires into service is less than the tires you and I get from our local shop. Fresher tires=softer rubber=faster wear. He’s applying logic he learned from the tractor pulling community where aging/curing tires so they last longer is a real thing. I haven’t independently verified any of this – it seems like a great deep dive for our Autopian friends! ????
even if it’s got the same brand name, the tires you get from tire rack are not the same as the dealer has. OEMs always have a special blend/construction
The Renault Grand Scenic was designed to only have 20 inch wheels as a design decision. It’s an MPV which is a sector that has really been hit hard by changing trends towards SUVs. They wanted to design an MPV with a strong style and didn’t want that image to be undermined by base models running 16 inch wheels.
I read an interview with Laurens van den Acker where he indeed mentioned that the wheels were this big on purpose. It is even a special size, most 20 inch wheels are much wider than 195 mm.
makes sense.big wheels not only look better(not always though),they also hide your front overhang.Audi started this trend.
I love this, because from an engineer’s standpoint, OEM absolutely is the move, because it’s what everything is optimized for.
But as a driver, you’re probably willing to compromise in certain areas to get significant gains in others. Hell, you may not even notice the compromises that would bother an engineer (especially if they could see those compromises in the data).
What did y’all expect from a suspension engineer? IT’S ALL ABOUT OPTIMIZATION! 🙂
I’d love to see this explored further – certainly not disagreeing with this logic, but I also agree with many other commenters that sometimes OEM tires are absolutely the worst. So how does that happen? In what cases would aftermarket tires actually be better?
I’m pretty sure the aftermarket tires I put on my 2003 Subaru Legacy wagon are a lot better than OEM, whatever they were. For one, there’s 18 years of tire development since then. I also put on “ultra high performance” tires, when the originals were probably meant to be all-around all-season tires for a family wagon. The new tires have super grip and steering feel.
The problem is, optimized for what? A manufacturer is optimizing for vehicle sales. I want optimization for bad weather (rain/snow) and price, but am willing to trade away tread life and road noise. My car’s OEM tires (Nexen, for Kia Soul) were consistently among the lowest price tires at major vendors (Discount and Tire Rack), so I assume that (unsurprisingly) cost was a major factor in Kia’s choice. I’m happier with their non-OEM (General) replacements.
Unfortunately, the compromise that bothers the bean counters (and their traitorous engineer underlings) most, in many, many cases is going to be COST, pure and simple. In no way is the engineer the be all, end all in the story. Hell, Tesla can’t even get all four tires the same on their flagship vehicle at the factory. I would wager that most folks on this site absolutely know they have replaced tires that were better than OEM, in all respects, but they typically cost more.
Graphic example: 90’s Explorer Firestones. Guess the engineers kinda missed those. Whoah is the buffoon who replaced the passed on the Michelin LTX’s to slap Firestones on.
Firestone was scapegoated by Ford on that one. There was nothing wrong with that Tire. It was the recommended PSI coupled with neglect from owners that led to the Tires being underinflated on a high center of gravity SUV.
Had a 2015 Ram 1500 on lease . The Goodyear RS/A’s needed replacing just before the lease was up . The tires were the only Goodyears to not have a warranty . Guess who paid to have them replaced and guess who got to advertise ” New rubber ” to whoever bought it off lease ? I don not believe this to be a coincidence.
As a fellow engineer dealing with structure optimization, saying something is “optimized” doesn’t mean much if you do not explain the cost function!
It’s all about the target demographic the car has been made for, which determines the prevalent factors to want to optimize. I’m driving a 2nd (well, 4th actually) hand E85 Z4. BMW at the time designed a sporty-ish car for the well off German dealing with midlife crisis. That dude was gonna cruise the Autobahn and show off when going to the restaurant.
I bought the car when I was 26 and wanted to go track it and carve twisties. The use case is different, therefore the cost function is different and the previous optimum isn’t optimal anymore.
Since you brought it up, I’m curious to know more about the optimization process. In my understanding of the field of optimization, there is typically some kind of objective function, subject to various constraints. The magic is often in how the objective function is formulated (which I believe gets into the field of decision science) and then the search method used for the optimization, since many real-world problems tend to be non-linear and therefore often neigh-unsolveable (I think the math people call them “np hard”). I’m curious if anyone can comment on the decision science process engineers use to come up with the objective function – how do they balance factors such as ride, handling, cost, etc. to optimize? I have to think we’re past the “trial and error” method of optimization, right?
This reminds me to ask you guys to do an article on how great design gets bean counted into mediocrity in the end. I think GM is the biggest culprit. “Great tire! But is it cheap enough? We’ll go with this other tire….” They optimize themselves into a budget corner and then make…meh.
Aside from a few niche cases (Rubicons, Raptors, M/AMG/S cars, etc.), you know OEM tires are going to be chasing cost and MPG for those sweet, sweet CAFE numbers. If an owner doesn’t care about eking out every possible fraction of an MPG, I’d wager there’s even a good bit to be gained by going off-spec.
For sure. My wife’s Jeep Compass came from the factory with Pirelli Scorpion Zero ATR tires that were absolute garbage. They lasted 20k-ish kilometers and would stop working at the mere suggestion of rain. We replaced them with Continental CrossContacts (also ATR), that are better in every measurable aspect: cost 25% less than the Pirellis to replace, get about 10% better mpg, better grip and much better in the rain. I can’t see why one would keep the Pirellis in this case. Clearly Stellantis had a sweet deal with Pirelli for tires that were “good enough” but absolutely not the best solution for the car.
A good example of the optimization and compromise is hybrids. They almost invariably optimize for rolling resistance to maximize efficiency, which can lead to louder tires with acceptable (but not great) stopping distance.
On the Kia Niro forum I used to frequent, the hypermilers scoffed at anyone who was considering other tires, predicting posts complaining of poor gas mileage. Meanwhile, people wanted quieter tires that did better in all-season usage and were willing to sacrifice efficiency.
My car came with some very efficient Michelin tires from the factory.
I replaced them with the best (recommended by ADAC) winter tires after 8 months, and never put them back on again after realizing how horrible they were. (I always just pick what ever ADAC recommends in my tire dimensions, whenever i replace my tires.)
My car was wobbly, unstable and worst of all unpredictable with the original tires.
It is, predictable, stable but still soft with whatever ADAC has recommended since.
Interesting
Are you taking recommendations from Allgemeiner Deutscher Automobil-Club or someone else?
A short anecdote to explain why your OEM tire advice is not just wrong, but unobtainable for some vehicles:
When my truck was new, it ran through the stock tires in about 25K miles. When I looked into replacements, the helpful fellow at the tire store said that was normal, and non-OEM tires would wear longer. I asked if that was true for the same tire, and he proceeded to explain that while they carried a tire with the exact same name, it was noticeably different, including having a different tread pattern.
The only tire seller that could get the OEM tires was the OEM.
My experience with other brands has varied, but they have pretty much all been better than OEM in handling, and all have exceeded the treadwear.
I’m a little confused about the idea of “submissions” from the tire manufacturers. When they make a submission, it is just tires that they produce for their product line to sell publicly. For instance Michelin makes several versions of the Pilot tire that could possibly work for a certain car trim level based on performance, price, noise…, but they are not supplying Pilot Sport 4 tires in 5 different rubber compounds to see what the manufacturer likes best. Maybe on a high performance car they can do that, but imagine the logistical nightmare if Camry, Accord, and Outback all spec’d the same tire with different tread compounds.
Holvey, the tires a tire company submits are most definitely NOT just a sample of off the shelf tires. They are specifically engineered and built to the specifications of the OEM. They may have a familiar name on the sidewall but they are not the same.
Which brings home the point that the OEM tire may well not even be available to the public except, maybe, at a dealership’s service department.
Engineer here with another vote for not always sticking with OEM tires. The stock grand touring tires on my GTI had very little grip and took a lot away from the driving experience. Replacing them with the Continental DWS was a night and day difference. I would clarify that you should never replace your OEM tires with junky ones. I got burned by a set of performance Kumhos and then Toyos in my youth before accepting that tires were in the pay to play category.
I always take tire recommendations with a grain of salt as it is somewhat of a false comparison. You almost always experience an immediate improvement in feel as you are comparing freshly made brand new tires with old, hardened tires with little tread left.
Same thought, and honestly I had the same replacement in mind… My Giulia came with run-flat Bridgestones and they aren’t very grippy. I’m sure that plays into the handling dynamics of the car, but I’ve run DWS on a few cars in the past and they’re phenomenal (quiet, grippy, good in snow, and hard-wearing). I love the way the car handles but I expect it’d be even better with a more performance-oriented tire.
One other weird thing is that the Giulia has a square 19×8 setup but runs 225 width tires. VAG cars run 245s on 8″ wide wheels… I prefer the look of 245s on an 8″ wheel but I’m prepared to make that compromise assuming it was done for reasons of steering feel.
Tires:
Anecdotally, OEM tires on my 350Z were completely shredded after my first track day on them (as well as the brakes cooked and the oil dangerously high). They squealed like a pig and gave me zero confidence to hit apexes hard or take straights deep.
I’ve done two track days on mid-range (but reasonably priced) Hankook summers, and the experience is night and day. Once warmed up they gripped well and my upgraded brakes could clamp hard without skittering around.
Maybe for daily drivers OEM is best for fuel economy and ride quality, but for a performance car I don’t think the statement that OEM > aftermarket is always true.
I agree with the sentiment. Putting non run flat Michelin pilot sport on my Z4 improved steering feel and track performance.
But I do think this is an edge case not covered by Huibert’s advice.
Came her to post on how bad OEM rubber is, was not disappointed in the community outrage.
Never stick with OEM tires. That’s the worst advice I’ve ever heard, and completely bogus.
OEM tires are specifically built to a cost. The manufacturer wants to pay the least, the tire manufacturer wants to make money. Consequently, the tires delivered to the OEM are literally the cheapest rubber they can make while still meeting the OEM’s requirements. Which are almost always around durability and friction (for fuel mileage,) never performance. Not even Porsche selects for performance.
The original factory tires on the Porsche 997.2 of all flavors are Bridgestone Potenza RE050’s. “Those are performance tires,” someone cries out. No, they’re cheap trash which wears out instantly for no benefit. The specs speak for themselves; UTQG of 140A A, at a $300+ price tag.
Michelin Pilot Sport 4S N-rated tires have a UTQG of 300AA A. Meaning treadwear is less than half as fast as the OEM tires and grip is significantly higher. (But the OEM version that’s a cost option? I believe it’s 200-240AA A.) And let’s say you’re not feeling the full PS4S spice – even the Pilot Sport PS2s offer a 220AA A. Pirelli P Zeroes (what I run currently) boast a 220AA A too.
Sticking with the OE tire and wheel size? Yes.
The OE tires? Just one glance at the UTQG alone shows how wrong that is.
Rootwyrm, Cost is most definitely part of the compromise tire engineers have to make but it is not necessarily the dominant one. Keep in mind that tire manufacturers will make deals with OEM’s on price where they make very little if any profit on the hope that all those owners will buy their aftermarket tires a few years later. Aftermarket is where the money is!
That’s why I said cost, durability, and friction. And exactly – there’s zero margin in the OEM tires. Which is why they’re often not even made on the same continent as the ‘same name’ aftermarket. Much less from the same molds or carcasses.
Now go take a 5 minute test drive in a brand new Toyota Corolla with the OEM Firestone FT140’s. And tell me with a straight face that NVH was even considered. It wasn’t. I don’t care what anyone told you or anyone says, because anyone who says that interior noise well over 45dBA from the tires alone is acceptable is lying. It is literally impossible to have a conversation without shouting. Now go try them in snow – they are literally so bad as to be legitimately dangerous. And that’s the experience on less than 6 month old tires with less than 5000 miles.
But those shitty tires bought them another 1MPG for CAFE so they can ship more near-to-single-digit MPG Tacos and Tundras and/or a few pennies off the BOM so they can get higher margins. So anybody who might have given a shit if the coefficient of friction is so low that the ABS hair-triggers when it’s raining, the stopping distance is nearly 20 feet longer than SUVs that weigh twice as much, they aquaplane in a few millimeters of standing water, the interior sounds like a jet is taking off at speeds above 35MPH, and snow driving is one wheel ‘burnouts’ and uncontrolled sliding?
Was laughed out of the meeting.
I agree with most of what you say, but, and this is important, tread wear ratings are not transferrable between manufacturers. A 200 tire from Michelin is relative to other Michelin tires. It will last the same duration as a 200 tire from Goodyear or Firestone, etc.
Err, not last the same. Where’s the edit button.
Maybe not never, but for most accessible vehicles you are on the money. The Toyo Proxes that Mazda put on my 3 we’re horrendous. My mistake was that I didn’t replace them on day one. I put on some Conti Extreme Contacts and it’s handling in all situations is massively improved. Meanwhile Mazda made extra bucks on me as the Toyos picked up sidewalk bubbles going over even minor potholes and the only place to find the OEM match was at overpriced Mazda dealers. Seems they swung a deal with Toyo to line both their corporate pockets.
You should only stick with original rubber, if you agree with the engineering compromises which resulted in that tire being chosen. Please note that I said ‘compromises’. Because all engineering is based upon informed decisions by the design team, which may or may not fit your use case. In my experience, especially with performance vehicles and refit of older/antique platforms with newer products, the OEM stuff is rarely the best choice. On the other hand, if you are Ms. Jones, mall-crawling Queen of the Suburbs, no, you probably don’t need stance or dubs. So yeah. I see the point. Still, thoughtful modifications are part of what being an enthusiast is all about. Therefore, I think the gist of the article is misleading.
You are quite correct that automakers put a large amount of money and effort into the tire choice.
However, every choice is a compromise. What you can’t know is what priority the engineers put into that particular vehicle choice. Even if you did know, do their priorities match yours?
We as consumers now have tools for our choices that didn’t exist 20 years ago. Tire Rack tests a large number of tires each year, and posts the results. In the results chart, all the way at the bottom of the page, is normally a graph with the wet and dry braking distances and lateral g forces. It is amazing to me that the same size and type of tire, on the same car, and on the same pavement, can have a 50% increase in wet braking compared to dry braking.
For me and my family, on mostly street-driven vehicles, my priority has been wet traction. This has led to a few interesting choices:
Chrysler 300S, OE tire Firestone Firehawk GT. They may have been OK when new, but acted like greased snot in the rain when I had them. Replaced with Michelin Pilot Sport 4S. They didn’t last that long, but were great in all conditions, including wet and dry autocross.
Toyota Venza V6, OE tire Goodyear Eagle RS-A. Quite good, actually. Wanted run-flats for my wife, so got Bridgestone DriveGuard. Also quite good.
Ford C-Max Energi, OE tire Michelin Energy Saver A/S. I think they chose this for low rolling resistance; could spin the tires with just the ~20hp electric motor. Chose Michelin Pilot Sport AS4. Much better traction, but lost 15% mpg. Maybe pick Pirelli P7 run-flats when time to replace them, more middle-of-road on both traction and rolling resistance..
Honda Pilot, OE tire Bridgestone HP Dueler Sport. Had some no-name junk when I bought it, so they need to go soon. Ran the numbers, and the best thing currently available is the OE tire.
The worst set of tires I’ve ever had on a car were the OEM Firestone tires that came on my Honda Civic. One inch of slush and a slight incline meant I was spinning my tires. Handling was “scary” in weather. Replaced them, and all of sudden it was competent in all weather.
The OEM Continentals on my Subaru weren’t awful, but switching to Michelin certainly improved performance.
Same with my Prius. The OEM Bridgestone Ecopia tires were OK, but worn out at 35k. Replaced them with Michelins rated for 80,000 miles and they handle just as well and wear like they are made out of iron. Small fuel economy hit, but no big deal.
Other cars these days come with Nexen tires. You can’t tell me they chose Nexen because they are a superior tire. They are cheap, and the company wanted to save $100/set x 50,000 units.
I’ve had several cars that came with OEM Goodyears, and they were garbage every time. I don’t think a single set has lasted more than 25k miles.
I could not disagree more on sticking with factory tires! My mother in laws CR-V factory tires barred late 20k freeway miles before needing replacement, and their traction was mediocre at best from the beginning. Anyone who buys those again will spend easily double the amount needed on tires over a few sets and not have superior traction or anything else. Likewise with my Toyota sienna. Factory tires were noisy, has terrible traction in the wet, and only lasted 35k. Upgraded to a nice set of Yokohamas which still have good tread and traction 50k later, and transmit significantly less road noise into the cabin. I would never even think about buying the OEM tire again. Sizes sure, but definitely not the specific tire
A 50k mile tire sounds like one of the worst ideas ever for the average person. By the time you hit 50k that tire will have aged to the point of being dangerous in the rain and serious loss of traction in the dry. IE: hard as rock.
Maybe for the average person, we average 30k a year on the van so they’re literally not even 2 years old.
On the subject of OEM tires:
The first gen e-Golf in the US came with Michelin as the OE rubber. I am a big fan of Michelin and will always get their tires. VW had been using them as an OEM for many years as far as I know (my MKVI came with Michelin). But for some reason, probably cost, they switched to Bridgestone. Let me just say the OEM Bridgestones on the second gen e-Golf were utter trash, and downright dangerous in the wet. With only a few thousand miles on my two e-Golfs I went to America’s tire and ordered the previous OEM sku Michelin tires and it was seriously night and day.
Thankfully the OEM Bridgestones on the ID4 aren’t horrible, but it’s too bad there isn’t a Michelin sku.
So yeah, stick with the OEM, unless they’re utter garbage, which may very well be the case.