If you’ve ever looked at a tire size before, you’ve probably seen a letter at the end that has nothing to do with the tire’s actual size. That letter corresponds to the tire’s “speed rating,” which is the maximum speed that a tire can safely reach and maintain without falling apart.
These speed ratings are required on road tires in the United States, as they give consumers a clear idea of just how fast they can travel while maintaining trust in the tires not to suddenly give out at triple-digit speeds. Each letter represents the maximum speed the tire is good for. For example, if a tire has a “J” speed rating, it can go up to 62 mph safely. A “P” rating means the tire can go up to 93 mph.
For the most part, as you go down the alphabet, the speed rating gets greater. There are some exceptions, though. Here’s the full chart, courtesy of Discount Tire:
Note how the “H” rating is way farther down than it should be, and V, W, and Y are all higher than Z. These changes were made to accommodate the evolving performance arena, catering to vehicles with higher capabilities. From Discount Tire:
While most tire speed ratings increase in max speed the further along the alphabet they are, there are a few notable exceptions to this rule. In this system, tires with a Z rating would be the fastest rated tires out there. At one time, Z-rated tires were thought to be the highest rated tires a vehicle would need.
But the development of faster vehicles brought us two new speed ratings: W and Y-rated tires, both of which are rated for higher speeds than the Z despite their earlier place in the alphabet. These speed ratings provide a more precise indicator of a high-performance tire’s speed over 149MPH.
H is the only other speed rating that doesn’t appear in alphabetical order. A holdover from the early European speed rating system, the tire experts of the time chose not to change the original rating indicated by H.
From the factory, passenger vehicles must have tires that can handle their top speeds. Otherwise, manufacturers would be putting customers in a dangerous situation right off the bat. Ram is recalling a bunch of 2500 models built between 2022 and 2026 over “speed calibrations” that can exceed the factory tire speed rating.
According to Ram, the 2500 has a top speed of 105 mph. The 2500 gets a tire with an “R” speed rating, which means the rubber is good for 106 mph. From the sounds of it, Ram seems to have inadvertently set the top speed for the affected trucks higher than 106 mph, which is where the problem arises.
Thankfully, the issue didn’t rear its head due to a crash or injury—it came up during an internal Stellantis review back in March, which flagged the potential dilemma. A total of 12,736 trucks built between June 2022 and April 2026 are affected.
Instead of replacing the tires with higher-rated rubber, Ram is going to reflash affected trucks’ ECUs to lower the top speed to be within acceptable levels for the existing tires. For the vast majority of 2500 owners, they won’t notice any difference. But if you’re one of the few truckers maxing out their 3/4-ton pickup on country back roads, then you might run into a speed limiter where there wasn’t one before.
This is one of those cases where you might not want the recall done. Who wants a lower top speed put on their truck? If I had one of these 2500s, I’d equip a tire with a higher speed rating instead. This solves the problem and allows me to keep my higher top speed. I can already see the Facebook Marketplace listings. “For Sale: 2024 Ram 2500 In Good Condition—NO RECALL DONE, HIGHER TOP SPEED!!!”
Sadly, some states, like my home state of New York, won’t renew registrations if your car has an open recall. So I’d be out of luck. But if you’re in a part of the country that doesn’t really care whether you have recalls done or not, congrats! Your truck has a higher top speed than advertised. And so long as you keep it away from a Ram dealer, no one should be able to take that away from you.
Top graphic image: Ram; DepositPhotos.com
So don’t take it in for this recall, got it.
A lot of the GM sedans I had as rental cars back in the mid to late 2000s must have come from the factory with S-rated tires. Sedans like the Regal, Grand Prix, Intrigue, etc.
So many of them would just cut out at around 110 or 111 mph. Some were still in 3rd gear and pulling hard when they cut out.
My rule with rental cars was that they came from the factory with way too much rubber on the drive tires, so I did my best to rectify that before I returned them. 🙂
So I can blame you for the Charger I rented that had bald rear tires? ;P
Nah, the company I worked for used Avis, and they never had Chargers available, Back then it was mostly GM products.
Yes base model W cars usually were limited to 110ish, the higher spec (ex. Intrigue GLS, Regal GS, Grand Prix GTP) often had H rated tires to 130MPH, although most did not make it to those top speeds…
I can see this. That’s too close of a margin for a truck someone might overload and take down the road without enough air pressure. Much cheaper to update software than buy new tires.
Not even gas prices makes them slow down, 5AM is like a race track around metro detroit, lifted trucks chasing each other to get to work with their monster energy drink and cigarrete flying out the window.
They are so anti electric they smoke analog cigarettes instead of vaping!
And blowing empty plastic Fireball bottles out of the bed when the air catches them just right
Not to mention they all have M/T tires with even lower speed ratings…
Welcome to my commute, 696 EB before the construction is a challenge for who gets to the construction zone first…
“Instead of replacing the tires with higher-rated rubber, Ram is going to reflash affected trucks’ ECUs to lower the top speed to be within acceptable levels for the existing tires”
I suspect that this is one of the safety updates most owners won’t care about and skip.
Now having said that, even 105mph is way faster than any truck like this should be going.
Also… no love for an X tire speed rating? Given how so many trim levels and vehicle model names rely on ‘X’, you’d think the industry would LOVE to have an X-Rated tire…
I never thought it would happen to me, but there I was at the tire shop, with the most beautiful woman I had ever seen working as a tire tech. She was looking at my x-rated tires and talking about plugging holes…
I asked her if she charged extra for mounting.
So are we starting an “Autopian Letters” section…?
“They don’t have tread,” she told me. “They have ribs for my pleasure.” I bought two sets.
There’s an X-rated tire, but there’s no tread left on it.
I’m noticing that tire rating chart conveniently skips over X. Apparently, there are no “X-Rated” tires, which I’m sure is a source of endless frustration for RAM owners.
Firestone could make them, you know, for when the rubber meets the load.
Ultimate protection in the wettest conditions.
Unmatched grip when the going gets slippery.
Now with white walls.
Ribbed tread pattern for her pleasure.
One year of emergency coverage in case any holes develop.
I posted before I read yours. Didn’t mean to steal your line.
“That’s right ladies, my rubbers are X-rated”
X-Rated tires, for when you want your ride to feel like you’re on rails.
This reeks of auditors gonna audit.
Reflash the RAMs, a few mph slower isn’t gonna get Jim-Bob away from the Arkansas State Police. They PIT up to 130 anyways.
“This reeks of auditors gonna audit.”
It is their sole job. Honestly it is a pretty good catch.
Hi have you met your average Ram owner? “Back roads” lets be real, they’re doing that in the right lane on I-95.
Right lane? People move back into the right lane where you live?
I’m jealous.
They do when the person in the left lane is “only” doing 80 and they want to go faster and not wait.
I drove across WI on 94 yesterday and the left lane was mostly 15-20+ over, just nuts. People doing 85-90 one car length or less between all of them .
I did too, and it gets worse when you get into IL on 90.
90 mph is not enough to keep pace in the left lane, you’ll be angrily passed on the right.
I was going east to west. Glad you made it safely.
No, the right lane is actually the fast lane in many places because people want to camp out in the left lane and won’t yield to faster traffic.
401 through Toronto. Keep right to pass everyone.
Many places don’t pave the right lane.
If you want slow traffic in the right, get dot to pave it.
Both lanes are usually gridlocked here anyway.
This is my experience too. I just didn’t think ahead enough about the reverse that drives the fastest drivers back into the right lane to pass.
That sucks. Where’s my tiny violin….
Around me, RAM drivers will tailgate you in the right lane at 5-10 over the limit for miles and miles, while the left lane is wide open
You end up moving to the left not to pass, but to let them pass on the right.
This is relevant to trailer tires. So many of the cheap ones are J (62 mph) rated. Like, why are those even allowed for sale?!? Yeah, someone probably has a small trailer pulled by a quad that won’t go past 40 or so. That said, a small trailer going down the freeway at 75 mph hopefully has M (81 mph) rated tires. Or a camper. At least buying M rated tires is some assurance the tire isn’t a China bomb.
Yeah and that is not something they tell you when you buy the trailer or replacement tires. I am honnestly more surprised that I don’t see more trailers on the side of the road with failed tires. It isn’t that uncommon for me to be doing 75 mph in the middle lane while some guy towing his boat/travel trailer/work trailer blows past me.
I was pleasantly surprised that my cheap Tractor Supply utility trailer kit came with M rated tires, which is faster than I need.
Good luck. China isn’t known for strictly following quality standards.
It was built in Canada by a greenhouse maker.
“Hello, daddy, hello, mom
I’m your ch-ch-ch c̶h̶e̶r̶r̶y̶ China bomb!
Hello world I’m your wild girl
I’m your ch-ch-ch c̶h̶e̶r̶r̶y̶ China bomb!”
Turns out this is an issue with every truck manufacturer, but only RAM had to do a recall because of their clientele.
They don’t want a blowout when they’re tailgating a car that’s already going 30 over.
I’m kind of frightened to ask, but what would the stopping distance on a crew cab, well optioned 2500 4×4 going 105? 600 feet not including reaction time?
Assuming the tires hold the road, they should have pretty good stopping distance. The brakes are rated for both towing and max payload. So Billy BadAss in the left lane with his vanity truck COULD stop fast. The question is if he will.
Slamming on the brakes would threaten his “image”
The degradation with weight isn’t linear especially with larger tires and brakes.
Mostly an issue with wet weather.
Still not smart to park in my braking zone, but people do it all the time. Two wheel drive in my case.
Nah, it’s even more frightening than that. *No one knows*, ’cause Heavy Duty trucks in the US are exempt from both safety requirements and testing.
In pure theory mass doesn’t affect stopping distance because it’s directly proportional to friction force and to kinetic energy. So as you get heavier and have more kinetic energy you also have more friction to counter the KE.
Of course in reality this doesn’t work out because we have to account for a tire’s available friction and the braking systems capability and material sciences and the available sizing/package prevent scaling these components to provide the same performance at the increased mass.
With all that said it takes a good 500 feet to stop from 100 mph without adding reaction time. Just using pure theory and 0.7 for u: d= v^2/ 2ug. Add another 100 ft for reaction time and then some more if they are low coefficient of friction tires.
“Sadly, some states, like my home state of New York, won’t renew registrations if your car has an open recall.”
What do people do when there’s a recall but parts aren’t available? I had a car in 2019 with an open recall on the Takata airbag, but parts weren’t available to fix it.
“What do people do when there’s a recall but parts aren’t available?”
Well they’ll just have to buy themselves a Prius then…
I believe they call the OEM and have them help. I had a customer who ran into that for the passenger airbag recall on his older Ram and got an appointment for it at a PA dealership within like a week or so of calling Stellantis: a rep will actually do the leg work to schedule it for customers, apparently.
When I say parts weren’t available, that’s the status that was shown on the NHTSA website as well as the letters the manufacturer kept sending me, so it wasn’t a matter of getting parts to the dealer; they just didn’t exist.
Manufacturer communicates with the state DMV. My Civic open recall for the fuel pump didn’t prevent me from renewing my registration until Honda sent out a letter to owners that said the parts are now available for the recall.
Buddy of mine LS-swapped his Geo Metro and had to search long and hard for 13″ Y-rated tires. The entire exterior remained stock as he wanted this to be true sleeper build.
When I owned a Metro I dreamed of doing something like this, but of course I never did. How did he get the LS in there? Did he modify the suspension and brakes, etc. to handle the power?
Let’s just say that plenty of additional structural elements were added, and also he moved the firewall back into the passenger compartment a few inches to get it in there. While the outside looked like a Metro, most of the mechanicals had to be completely redone to put a longitudinal small block in there. The back seat was also removed and replaced with some carpeted panels and shelving as the front seats were moved back a few inches to deal with the firewall moving.
I’m sure that was a ton of work. Hopefully the end result was commensurate. It sounds pretty cool.
Why is the rear tire so narrow in the top shot? It almost looks like one of those compact temporary spares; made me think that the issue was that owners were driving far too fast on their spare tires.
Picture smells like AI…
It smells like the front tire was copied, sliced, and stretched to fit the rear aspect better. (I’ve done similar just to get curriculum out the door on tight timelines. Macaroni & Fuck it)
I agree – same flame pattern. Just a quick chop shop photoshop, no need to ring the AI alarm.
Well, no offense to Brian, but it looks very half-assed either way.
The header image with the flaming tires made me think that if they remade Krull and set it in the modern world, the characters would be riding Fire Rams. Just some random thought. Maybe because I think Krull is ripe for a re-make but I’m sure Hollywood would still cock it up.
Did you tell NY that? I have a co-worker who still hasn’t done his Auto-Park recall on his Ram 1500 and he has renewed his registration a couple times since the recall came out, AFAIK.
So what’s the top speed when there is no letter after the tire size?
Walking speed.
Whatever speed they end up blowing out at, that speed minus 5mph is rating.
Feel free to test and get back to us.
Same principle as the bridge load limit rating, as explained by Calvin’s dad.
Most young males figure out their load limit once they hit puberty.
I know the exact strip you are referencing. Bravo.
To infinity and beyond!
Everything just sounds so dire these days.
This is probably more common than we think on trucks that offer a variety of tire diameters and rear end ratios. A set RPM for fuel cutoff corresponds to quite a variety of actual road speeds even with the same engine and transmission.
The fact that it’s only 12,000 trucks over a four year period; a tiny fraction of the number built, makes me believe the issue is limited to one optional tire size + rear end ratio combination.
The speed limiter is not a rev limiter, it is based on the VSS signal. So as it leaves the factory the computer should know the actual tire size and gear ratio it is equipped with so that the speedo actually reads correctly. Sure once it is out the door someone may change the tire size or gear ratio and not do the proper adjustments in the code to correct that.
You’re right and I didn’t word my first comment very well.
I still think one combo of tire size and gear ratio was probably miscalibrated in the VSS. It’s measuring speed at the transmission, not the wheels, so a faulty input can make the wheel speed calculation wrong.
Yeah considering the number of vehicles affected it is almost certainly one particular gear/tire combo that someone messed up the math or made a typo while programming.
“Dammit, I always do this, I always screw up some mundane detail.”
Trucks are very commonly reconfigured.
This might set the standard for stupidest recall ever.
Also, why bother having a speed limiter in a 3/4 ton truck if you set it to 105 mph? I don’t think many owners would care/notice if you set the limit to 90. If your company’s lawyers are strict/irritating enough to make you issue a recall because they can go 107 and their tires are rated for 106, you may as well give yourself more margin of error.
The speed limiters have always been there because of the tire ratings.
Unless you drive something like a Chevy Aveo, whose top speed is “aerodynamically limited”.
The Chevy Sonic is also aerodynamically limited to roughly 124 MPH.
Yeah, I know it is due to tire ratings.
I’m just saying if you are going to do a speed limiter on a vehicle that is the polar opposite of a sports car, why set it to 105 when you could set it to 90? It is fine if your tire’s maximum speed is 30 mph above your limited speed.
Ask Firestone who gets the blame when it comes to tire failures.
I mean, you’re not wrong and I’m not necessarily arguing with you.
I just can’t understand why they don’t engineer themselves a bit more margin of error. I doubt any customers would choose a competitor’s truck solely because their trucks are limited to 90 instead of 106.
Just set the speed limiter well below the tire’s rated limit. Literally no buyers are going to care.
If they set the limit lower, the bean counters will probably just make them buy lower rated tires that are cheaper.
Fair point.
It just seems so stupid, though, that the bean counters and lawyers make this difficult for no reason.
But if nothing else, isn’t this stupid recall going to cost them some money? It seems like the bean counters are short sighted.
Not to beat this dead horse any further, but isn’t there an obvious solution that pleases the lawyers, bean counters, and customers?
If 1 mph above the tire speed rating is enough to trigger the lawyers, 1 mph below the tire speed rating is enough to trigger the bean counters, and buyers couldn’t care less about any of this, maybe set the limiter to 1 mph above the speed rating of the tires rated one rating slower???
If the limit for Q-rated tires is 100 mph and the limit for R-rated tires is 105, it seems like bean counters, lawyers, and customers would all happy if this truck had R-rated tires and the limiter was set to 101 mph.
I just can’t get over the sheer stupidity of having to issue a recall because some jabroney forgot to carry the two when calculating the correct speed to set the speed limiter when not one single customer in the history of 3/4 ton truck customers has ever decided not to purchase a 3/4 ton truck because it can go 101 mph instead of 105.
Ok whatever
No, the album name is “OK Computer”.
The (early ’00s?) E250s I had for work were limited to 90. It was for the best.
Yeah, 90 mph is plenty fast for even the newest 3/4 ton trucks. I figure wanting to drive a 3/4 ton over 90 mph is evidence the driver does not exercise good enough judgement to safely drive a 3/4 ton over 90 mph. Modern 3/4 ton trucks are impressive machines, but the laws of physics as yet remain undefeated.
That is why I am surprised they set the speed limiter so close to the speed limit of the tires. It seems like a lower limiter and a bit more of a buffer between limiter speed and maximum tire speed would have zero downsides. I think I have had my truck into the low 80s to pass someone a few times, but that is it.
At 90, the Econoline with a roof rack was pushing a wall of air that made it feel like a normal car driving through surf and the rack made a hell of a racket. I wouldn’t do that today.
You haven’t met many RAM drivers.
Apparently you haven’t either. I see a lot of them in traffic, though. Most are going generally the same speed as everyone else. On occasion a few of them might be going 85, but that’s about it.
I’m sure some Ram driver somewhere at some point has gone 100 mph in their truck, but it isn’t common.
In Michigan, the lifted pickups with tinted windows will go 90mph+ on a daily basis. Thinking at it from a physics and safety standpoint, it blows ones mind.
Screw the Firestone debacle! I want to choose the tires for my next new car, but instead I’ll need to take the mandatory summer tires (in the midwest, but the model I want is RWD) and take a bath to get rid of them when I dump them for all-seasons.
Can confirm.
I worked for Thrifty Rent-A-Car in the late 1990s. We had Chrysler 300Ms.
We got different trims of this car; some with 17″ wheels, and a luxury variant with 18″.
The 18″ cars had a limited top speed of ~127 mph. The cars with 17″ wheels had V-rated rubber for some reason and were good for 140+.
I was 18 and stupid, OK?
“I was 18 and stupid, OK?”
Why are you calling yourself stupid? You OBVIOUSLY learned this information by studying technical data and NOT because you pushed any cars to their speed limits on the road, right? RIGHT???
I had a Giulietta diesel which I once got up to 140+ too and the tyres were rated for that speed.
I was stupid too though.
Not in Europe though (except for Volvos, some hybrids / EVs and the German’s 155mph gentlemen’s agreement).
A Skoda Octavia diesel tops out at 145mph for example. And that’s drag limited.
US spec MK7 GTIs have a 124mph speed limiter because they come with H rated tires from the factory. Mine would pull hard until it fell on its face at the limiter.
Yup, 124 and it runs outta breath
If I was an affected owner, this would piss me off in theory, more because I’d need to decide between buying tires with a higher speed rating and dodging a recall for the rest of the time I owned the truck, or just doing the recall and accepting the limit.
Pretty sure I never exceeded 80 in the last truck I owned, but still . . . It’s the principle of it.
Aren’t all trucks already limited to a speed well under what it would actually be capable of going based on gearing and power?
My F250 is limited to 95 mph which in 10th gear can’t be much more than 2,000 rpm (I have no idea – I’m not sure I have ever gone over 80 even briefly). With 475 hp/1050 torques I presume my truck has more than enough power to overcome wind resistance well above the factory 95 mph limit.
If Ford sent me a recall notice saying it needed to lower the limit to 105, I’d throw away that recall notice even faster than I’ve thrown away the previous twenty or so I have received.
It most definitely can go faster than the 95mph limiter. A 2015 I was moving between dealers felt like it fell on its face at 95mph when I allegedly tested the capability on a deserted straight highway.
Early ’00s or so E250s I had for work would slam the limiter at 90, so your F250 could definitely exceed that.
You’d think so, but I’ve been passed by dually pickups going 90+, so the manufacturers either upped the high gear, or people are pegging it on my midwest freeways.
It’s disturbing that some states don’t do the basic due diligence to ensure that recalls are complete.
I’ve often found it difficult to get a vehicle in for a recall in a timely fashion.
One on my wife’s Dodge a few years back took almost 2 years to resolve, not through lack of effort on our part.
I don’t blame states for not wanting to track that mess.
Many states don’t even do safety inspections so you could be doing 110 down the freeway in your massive truck with the cords showing through on your tires and it wouldn’t be an issue with the registration.
There’s a small element of logic that could catch brief airtime in the stiff breeze of a tornado to not checking a car that’s already registered and currently on the road. It’s how you get so many Northern cars held together with bailer twine, duct tape, and structural rust riding on baldAF tires.
Dont forget carpets. I have definitely seen cars that the carpet and wiring become structural with how bad the rust gets.
Living in a non inspection state I see pickup trucks that flex in the middle because the frame is rusted in half and literally totaled cars that have been utterly destroyed driving around all the time. Cars drop parts so frequently that all of the people who live around here have grown adept at dodging them. Even if it’s prone to exploding, a car with an open recall probably wouldn’t be the most unsafe thing on the road, at least in this part of the country.
Yikes, theses are speeds people should not be even close to doing on public roads in 3/4 ton trucks (or any thing else for that matter).
I wouldn’t be sure they “inadvertently” set the top speed to higher than 105. You have to account for tolerance in the speed sensors, tire inflation, yada yada yada. If the tire can handle 105 you should probably set your top speed to 100 or even lower.
Who is going that fast in a 2500 anyway?
The majority of Florida.
Last time I was in Florida, traffic was ridiculously slow everywhere. More like island time than a Grand Prix.
Granted I was a ways away from the Freedom Factory . . .
So true. I had my cruise control set at 79 and people on I-95 south of Jacksonville and along the Space Coast were blowing past me like I was standing still. 99 is fine, 100 means pain.
Waaaaaaaaaaaaaaaayyyy too many YA males.
Driving into work this morning a lifted bro-dozer with a goofy ass giant exhaust tip facing straight down stop at a red lot of an intersection I was driving through (I had the green) and he was going to be turning the same way I was going. I had the thought watch the lifted dude bro will catch up to me when I already go 5-10 over (it is a 55mph highway so I set my cc normally that much over and cruise in the right lane). And wouldn’t you know it a few miles down the road he flys past me going 80+. Was hard to tell in the dark but was either a dodge or fjord 250/2500 (possibly 350/3500)
I see plenty of 30-50 year old males also pushing their pickups to some pretty questionable speeds.
This sounds like it rates as important as floor mats in a Toyota.
Yo dawg, I heard you like floormats in your Toyota, so I stacked a dozen floormats in your driver’s side footwell for you.
I heard you like floormats so I gave your floormats floormats!
So you can accelerate while you accelerate
Yes! And also accelerate when you don’t accelerate.