To properly understand how something works, the best way is often to take it apart. Munro & Associates has made this its primary business, pulling apart vehicles and benchmarking not just how they’re made, but how much it all costs. One area of interest of late has been the cooling systems used in modern EVs. Like a few of its contemporaries, the Porsche Taycan uses a rather complex system, according to the gang at Munro, and it’s something that the firm thinks could be readily improved in future.
Effective cooling is a big deal for the Porsche Taycan. Unlike some EVs, it’s not intended to be solely a commuter, but a sports car as well. That means it has to be able to manage heat effectively to ensure its motors and batteries remain in a safe operating range during extended periods of hard and fast driving. To that end, Porsche put a great deal of importance on the cooling system. Given the car’s performance, it could certainly be said to be effective, but it’s perhaps not the most efficiently designed from a manufacturing or maintenance perspective, per Munro.
[Ed Note: When the Taycan came out, Porsche was sure to note that, while Tesla’s Model S may be quick, the Taycan can remain quick hour in and hour out at the track. To do that required lots of focus on battery thermal management -DT].Â
As revealed in the teardown by Munro & Associates, the cooling system is obviously highly complex, even at a glance. Described as a “bowl of spaghetti,” it’s a thick mess of valves, pumps, and pipes going every which way. Let’s dive into what’s going on, and the flaws that come along with designing a cooling system like this.
The Taycan has three coolant pumps, six valves, two fans, and a full complement of ten coolant temperature sensors. There is a single main coolant radiator, as well as a condenser for the air conditioning system and associated refrigerant loop. The latter allows the Taycan to monitor coolant temperatures across the vehicle, from the motors, to the inverters and the battery pack. All these components and systems have ideal operating temperatures, which can also vary depending on the desired mode of operation for the vehicle.
[Ed Note: It is worth mentioning that many modern gasoline vehicles, especially turbocharged engines with EGR and liquid cooled throttle bodies and transmission oil coolers and heaters (and especially hybrids), have similar “bowls of spaghetti” underhood. -DT].Â
For example, when the vehicle is operating in Range mode, it’s desirable to run the coolant pumps as slowly as possible to save energy that could better be used for getting the car down the road. Meanwhile, in Sport and Sport Plus modes, the cooling system is run to keep the battery in a far narrower optimum temperature range for maximum performance, at the cost of greater energy expenditure required to do so.
There are three main coolant loops in the Taycan: A low-temperature circuit that runs at under 104 F serves the main traction battery and charging circuitry. A mid-temperature circuit runs at a slightly higher temperature, between 104 and 150F, and serves the motor and drive modules. Finally, a higher-temperature circuit, running at up to 194 F, is used to provide heat to the HVAC system, using an electric heater to help generate those higher temperatures for cabin or battery warmup.
Ultimately, the complex arrangement of valves in the front of the Taycan control how coolant flows through these various loops, keeping them all at the appropriate temperature for the current driving or charging conditions. For example, warmer coolant from the high-temperature loop can be passed to the battery cooling loop to precondition the battery to the proper temperature for driving or charging in cooler conditions. The air conditioning system can also help control temperatures in the battery cooling loop by virtue of a heat exchanger between the two. Porsche states the thermal control system is capable of 300 distinct states depending on the vehicle’s current status and mode of operation.
With so much complexity, you could forgive Porsche for designing such a complicated network of pipes and valves and fittings for the cooling system. However, as Munro & Associates have noted before, it doesn’t need to be this way. In the design of its EVs, Tesla has focused on compacting and optimizing its cooling systems, drastically reducing the size and complexity involved. A car like the Model Y has a similarly advanced cooling system, but it’s achieved with a far sleeker, slimmer, simpler implementation. This is demonstrated ably when Munro & Associates compared the Model Y to the barrel of snakes that was the Ford Mach-E’s thermal management system.
The Mach-E’s cooling system, much like the Taycan’s, is seen here constructed from many disparate components. Individual four-way and two-way coolant valves are linked together with pipes, connectors, and clamps, and held to the vehicle with more brackets and fasteners. Pipes and tubes are going every which way, with coolant and refrigerant lines winding around corners and other components in complex twisting paths.
The Model Y eliminates much of the rats nest by mounting components directly together — integration. By combining components, it cuts down on the number of pipes needed for interconnections, along with fittings and clamps. Similarly, there are far fewer mounting brackets required to hold pipes and valves onto the car’s body, because everything is assembled on to a single cross-car mount. This has the dual benefits of making the system more compact, and reducing the number of potential leak points. This pays dividends for service and maintenance down the line, for end users and the automaker alike. Tesla’s Octovalve made headlines a few years ago for this very reason. It combined the functionality of multiple separate valves into a single unit, simplifying the design, reducing the parts count, and drastically slashing the number of hoses and fittings required to complete the cooling system.
The difference between the Mach-E and the Model Y is stark. The Ford packs in over 60 feet of hoses, compared to just 20.8 feet in the Tesla. This comes with a hefty weight penalty, too, since all those hoses are full of fluid. Munro & Associates calculated that the rats nest in the Mach-E is full of 49 pounds of fluid, compared to just 20.3 pounds in the Model Y. In total, the Mach-E has 35 individual hoses, while the Model Y has just 10. That’s a lot more parts for Ford to source, stock, and maintain over the lifetime of the vehicle, all of which costs money. Sandy Munro himself made a big show of fainting when he first saw the Mach-E’s cooling system. It might be a bit of amateur dramatics, but it goes to show the huge gulf between Ford’s design and the more compact Tesla layout.
Munro & Associates hasn’t yet fully pulled apart the cooling system in the Taycan, but it’s clear that it’s much the same story as the Mach-E. It’s all done with individual valves dotted all over the place, linked with a dense maze of hoses and connectors. Each individual component that needs its own brackets and fittings adds significant cost, as each and every part number has to be manufactured, installed, and tracked.
The real story here is that there’s huge scope for Porsche, Ford, and other automakers to improve in this regard. Where a nest of valves is hooked together with multiple pipes, perhaps they could instead be bolted to a single manifold to simplify things. Even better, multiple valves could be integrated into a single part, ideally one that bolts directly to a coolant reservoir with no pipes, connectors, or clamps required. Have the pumps affixed in a similar manner, and you’re suddenly slashing the number of parts involved and the number of areas where fluid can leak out or things could go wrong.
The one thing that this requires is time and investment. As Tesla’s example demonstrates, it requires the design of unique pumps and valves that are specifically intended to work together. These can’t be had as commercial off-the-shelf parts, or simple modifications of those, so they need to be designed and manufactured from scratch. Indeed, the benefits come from creating a cooling system with a high level of integration, so everything from pumps to valves and tanks must all be redesigned as a whole to fit together as neatly and compact as possible.
In Tesla’s case, making this huge investment in engineering and manufacturing makes sense. If you’re building a million cars a year, the initial investment is quickly offset by the savings made on each car in volume. It can be harder to justify this spend for lower-volume production runs like the Taycan, which typically sells under 50,000 units a year. Engineering time, too, can be a valuable resource, and other areas of the car may have taken precedence.
Regardless, there’s great value to be had by simplifying and improving an EV’s cooling system (including weight reduction). The benefit is that there is a great potential to reuse a well-designed cooling system across multiple vehicles with similar performance parameters. That can help further amortize the cost of development, too. In any case, Tesla has shown the way when it comes to developing these systems and optimizing them for manufacturing. Expect many other automakers to follow their example as their EV lines grow and become more mature in coming years.
Image credits: Munro Live via YouTube Screenshot, Porsche, Design911 Center for Porsche
I’m curious about how complex the cooling is in the Audi RS etron GT. It appears as a slightly de-tuned version of the Porsche Taycan with same battery and motors but I’m wondering how much of the components and engineering is shared between them.
I’m going to suggest a similar but different reason for all this; supply chains. Both Ford and Porsche have a longtime history of suppliers. And these suppliers do it a certain way. So, they get a rats nest of pipes, cause that’s how they always do it. And, this first round of EV’s by non-Teslas are all done with their existing suppliers, and how it’s done there.
This is the HUGE benefit Tesla had, and extremely clever, in that they had a fresh sheet of paper EVERYWHERE. They chose their own path with that long term, shared component concept from the beginning.
If I had to guess, everyone will eventually converge on the same thing, because all the thermal systems are going to be basically the same, like transmissions have gotten. No reason to reinvent the bolt of you don’t need to *cough* torx *cough*.
What happened to everyone promising me that EVs do not need coolant and cooling systems because they are way simpler than any ICE vehicle and that is why they are cheaper to buy and run from day 1.
EVs were not supposed to have:
Whichever strawmanWhoever told you that was talking out of their rear end. EVs have always been touted as being mechanically simpler (which they are) but I’ve never heard anyone claim they won’t need some kind of cooling system.Now I’m imagining that beans scene from Blazing Saddles, but in an office conference room full of engineers.
Well, other than Nissan.
EVs have always used cooling systems. They just don’t need as *much* cooling. The radiators and such are much smaller.
They also have transmissions. It’s usually just a single gear step down though so it’s mechanically simple and much more reliable
If I were going to own any of these vehicles outside of warranty, I’d rather have the bundle of snakes.
Using integrated manifolds and pumps could reduce parts count versus the hose and off the shelf pumps and valves. One thing I know for sure is that when it comes time to replace something like a single failed pump or valve it’s going to be a helluva lot cheaper than replacing the entire integrated valve / pump / manifold component.
Tesla horror stories are out there already of expensive battery replacements being the only official option to repair a damaged plumbing fitting.
And that plastic manifold from Porsche looks great in a picture. It also looks like a part that will turn an otherwise simple pump or valve replacement into a nightmare when that plastic gets a little brittle and one of the ports snaps off. That replacement manifold will be hard to find or expensive to purchase (quite possibly both).
Watch some of Munro and team’s videos, they almost never comment on (or seem to care about) repairability, just manufacturing costs. They love adhesives and hate fasteners. I like some of what they do, but they seem to be fully on the side of “car as disposable consumer product”.
That was my first reaction too, and I often criticize Munro for ignoring repairability concerns (which, to be fair, is not their job. They’re all about reducing manufacturing cost). However, in this case I’m not positive that separate valves are actually better from a repairability perspective. Once the valves start to go bad (which they will), you’re going to end up playing whack-a-mole with bad valves. If you’re lucky the valves each throw a separate code so you know which one went bad (and you’ll probably need a dealer computer to get this code), if you’re not they’ll all set the same code and you have to test them individually. Either way, once you replace one 10 year old valve, chances are another one will fail in another year or two, and another a year or two after that, and so on until you have 10 different ages of valve and there’s a constant stream of failures happening.
If they’re all integrated into one part you just replace the one part, which admittedly will cost more up front, but now you’re good for the next 10 years again. And yeah, you could do the same with the individual valves and just replace them all at the same time, but then the cost benefit goes away and you have more labor because they’re all individual parts.
It’s similar to my philosophy on battery modules. Yes, you can replace individual modules as they go bad, but then you’re left with a battery still full of old modules waiting to die so you’re going to be replacing modules forever until you’ve replaced all of them anyway. I’d much rather do the whole battery (and pay the labor cost) once. Plus then you aren’t driving around with a bunch of ticking timebombs waiting to strand you somewhere.
This may be true for the first out-of-warranty owner, where the car still has the value and remaining usefulness to justify replacing it all. The third owner may be replacing pumps / valves / hoses on an individual basis.
There are always outlier component that fail before their designed lifespan. If that happens to one pump or valve, I’d rather have the chance to replace it individually.
True, but how often does that happen? Those outlier failures are, by definition, rare. Is it worth designing something to slightly improve the .1% case or should it be designed for the 99.9%? And even if you have one of those failures it’s likely to be covered under warranty since (from what I understand, anyway) premature failures are vastly more common early in the lifespan of a product. They’re not evenly distributed.
Yes… but this will have like four pumps. That’s four times the chance of one failing!
I just checked, and that cooling distribution block thing is not available from rockauto. I was surprised that what they did offer for the Model 3 seemed very reasonably priced.
There’s enough Model 3’s that someone will make an aftermarket replacement if they begin failing.
Interesting. This got me thinking about Munro & Associates business model.
Obviously they recoup the cost of these cars by selling info to any manufacturer who wants it. But how many would need details of the Taycan? Who else is making such a vehicle? Surely they’d have to sell each report for tens of thousands to break even?
And that may be the case.It wouldnt surprise me if they lose on some reports,just to keep their customers happy.All businesses do it right?
Anywho,just thinking out loud.Carry on
I would bet that their detailed reports do cost many thousands.
Any manufacturer trying to build performance EV’s which includes Ford, GM, Chrysler (Some time in 2040), Hyundai / Kia, would probably be interested in this information. It’s probably something they’ve been doing in-house anyway, and this saves them the cost of a few engineers’ time for the weeks it takes to tear down and document a competitor’s vehicle.
Even if they don’t sell enough reports on a given car to recoup the costs, I suspect they make it up in expertise being able to consult with other manufacturers with deep knowledge of how their competition is doing things. I suspect consulting is a bigger part of their revenue than the reports themselves.
I think any automaker working on EVs would be interested in how the Taycan works.
Particularly because Porsche seem to have done a good job of building a performance EV that doesn’t thermally throttle itself after a single hot lap!
The benefit of having engineering insight like that? You can sell it for big bucks to interested parties. It’s specialized information of great value.
Alternatively, automakers would have to stand up their own teardown crews of engineers, and it would take years to build a crew with the same level of experience. That in itself is a huge expenditure, so why not just buy the reports and insights from the pros?
The reports do cost tens of thousands of dollars. It’s useful to manufacturers who want to benchmark a car, or a system on a car, but may not have the time or resources to do it themselves
Munro creates reports on different design, engineering and manufacturing aspects of the vehicle. For example, you can buy a report that’s exclusively about the cooling system or one that’s exclusively electrical.
You can even send them an entire product or car and they’ll create the report for you. They also do a lot of engineering and manufacturing consultation to help cut cost and increase quality
Honestly I can’t wait till we get ACTIVELY air cooled BEV drivetrains, for “economy car” BEVs you don’t need liquid cooling and you could likely save a lot of weight by using fans instead.
Imagine how much better the performance of the Nissan Leaf would be if it had cooling fans for the batteries? In hot weather it would perform a lot better, when charging the batteries it would allow for faster charge rates. Liquid cooled battery packs have not only the disadvantage of having to carry such a massive amount of coolant but also that in cold weather the coolant sucks a ton of range when it’s dead cold outside, especially so if you park your BEV outside.
Automakers have been building cars with liquid cooling for so long liquid cooling is the only way they can imagine cooling the drivetrain of an automobile, including BEVs.
I think this probably won’t happen, as it would be difficult to do stuff like battery preconditioning in super cold environments without a liquid cooling circuit. I could be wrong though, maybe something to look into further.
I think it would be pretty easy, put an electric heater in there with air intake and air exhaust shutters. When it’s really cold you have minimal heat loss through the system, when you need more cooling air the vents open more, so on and so forth. Also you could also heat the cabin quicker than a liquid cooled BEV. It’s definitely a ton more efficient to precondition an actively air cooled battery pack than an actively liquid cooled one as the air cooled one has less thermal mass to heat up than the liquid cooled one. Nissan Leafs (Leaves?) are Notoriously good in cold weather.
Out of Spec reviews made a couple vids where they BEVs to deep freeze over a night or two in below freezing temps. The Nissan Leaf accepted a charge immediately, it took a Tesla Model 3 ~45 minutes of preconditioning before the battery would accept a charge, over 4 kWh of power just on heating up the battery so it would accept a charge,
Heating battery packs by an air-to-air electric heater outdoors in the winter would quickly un-do any benefits of air-cooling (at least for 1/3 of the year in a lot of the US).
I’m also pretty sure the cabin heaters usually aren’t tied to the battery cooling system in BEVs. I at least think Tesla used kind of an electric space heater at first and now has switched to an electric heat pump. Neither option would need the battery pack at optimal temperature to heat the cabin.
They don’t need air to air heaters much, they heat up extremely quickly. Said thing was demonstrated by Out of Spec Reviews with his deep freeze vids I mentioned above. Nissan Leaf immediately took a charge. The Tesla took 45 minutes of heating at a supercharger to get up to temp enough to take a charge. 4kWh in heating alone.
I see no reason why you couldn’t tie in cabin heating with the battery so it just recirculates cabin air to heat the cabin and for air cooled battery packs it would make even more sense as it’s already air to air heating.
The leaf battery warms up faster because it is 1/4 the size of the Tesla unit.
It also takes longer to thaw a roast than a pound of hamburger.
Is the M3 battery pack 2700 times larger than the Leaf’s? Because the Tesla took 45 minutes of heating while plugged into a Tesla Supercharger using 4 kWh before it would take a charge. The Leaf started charging as soon as the charging session started, so lets do a little math here.
Leaf: 1 second to start charging
M3: 45 minutes to start charging
45 minutes in seconds is 45 x 60 which = 2700 seconds
By your logic the Leaf’s battery capacity must be 1/2700th of that of the Tesla Model 3 for the difference in battery warming up enough to start charging time is concerned.
GM shares the coolant loop from the battery, Motors, and cabin heater in order to increase efficiency. So does tesla. I’m not sure on other manufacturers but it seems to be fairly common to do it
I looked into the tesla heat pump and it’s apparently built into this whole integrated unit with the octo-valve. I can’t tell if they are just using the term ‘heat pump’ to refer to a pump circulating regular coolant or if it works like a domestic heat pump which operates kind of like a reverse-cycle air conditioner.
It works like a domestic heat pump to increase efficiency. Most newer EVs are switching to heat pumps for that reason. GM Ultium, Hydundai/Kia and VW all run them
Thanks. That was my understanding when I first read about them. Articles I found yesterday seemed less clear.
liquid cooling offers a lot of advantages over air cooling.
motorcycles, probably the optimum vehicle for air cooling have almost universally abandoned air cooling because you just can’t get competitive power, packaging and etc with air cooling.
the only reason small private airplanes still use air cooling is that the core engine designs are primarily WWII vintage and the cost of ground up certifying a new engine design is prohibitive when the existing engines are “good enough”
Said “advantage” doesn’t work when the battery is cold in cold temps, as the temp is “consistently” much colder than optimal and the only way to get it up to temp and keep it there is to suck a ton of power and by being colder for longer it sucks a ton of power. If anything air cooled batteries perform much better in the cold than liquid cooled ones. Since BEVs don’t generate much waste heat liquid cooling is a hinderance in cold conditions. You also need a lot more liquid coolant for a BEV battery pack than you need for an equivalent ICE vehicle.
Said density is only necessary for high power and longer range applications. There are plenty of BEVs that could be ACTIVELY air cooled instead. Again a Nissan Leaf with a fairly shoddy cooling fan modification will charge faster and preform much better in hot conditions. I am not advocating for EVERY BEV to have an ACTIVELY air cooled drivetrain, just mostly economy cars like the Leaf.
As previously stated I’m not saying ACTIVELY air cooled drivetrains are for every BEV, but on the low end of the market where the Nissan Leaf lives it would be a massive improvement over the Leaf.
Motorcycles on the low end of the power spectrum use PASSIVE air cooling almost exclusively today. Historically the overwhelming majority of motorcycles used PASSIVELY air cooled engines almost exclusively.
The most popular “small private plane” engine used air cooled cylinders (Rotax 912 series), most modern airplanes are build with either Turboprop engines (which are air cooled) or Turbine engines (also air cooled). The only reason we’ve seen an increase in the amount of liquid cooled engines in “small private planes” is mainly due to a lack of avgas in Europe and the cheapest way to make aviation engines that run on Jet-A is to adapt existing automotive diesel engines for said use case. From the ground up Aviation Jet-A burning Piston engines are almost always built as air cooled engines.
For economy BEVs they’re more likely to be parked outside for storage when compared to expensive BEVs. They’re more likely to be charged outside than inside than more expensive BEVs. They’re more likely to be someone’s only car than more expensive BEVs. Economy BEVs generally don’t have as much range as more expensive BEVs.
For such a vehicle an actively air cooled BEV makes a lot of sense.
That last paragraph is a weird hill to die on, considering this article is about Porsche.
This is either the EV equivalent of a transmission valve body, or a magic pan flute that will be used to summon the alien armada to finally finish us off.
Just have 1 mode and you won’t need all these pumps and pipes. Way to over complicate things.
It needs those pipes to keep cool at high performance. Without them, it would either be very limited performance, or horrendously inefficient.
Sure, but then you limit what the car can do. Porsche wants a car that can go fast and maintain high performance operation for a long time, but also a car that can go a long way at a calmer pace. The tradeoff is complexity.
All I know is that EVs do not need coolant and cooling systems because they are way simpler than any ICE vehicle.
This just in, German company over-engineers solution to problem. News at 11.
I bet the cooling system in DT’s Leaf is a lot less complicated. /s
It will likely become even less complicated if it gets dismantled for scrap.
EVs are Teslas only game. It makes sense for them to pour money into R&D and reduce the manufacturing costs. It meets their long term goals. Incumbent manufacturers on the other hand are only making EVs because they have to. If they could get away with not making them, they would. So it seems that they are not committing as much into R&D of subsystems because they haven’t seen the payoff and may not long term. It’s still a gamble for them.
Agreed. I also wonder if what we are looking at here is the most elegant solution within the parameters the engineers were given.
Yup, and I’m sure one of those parameters is to use existing parts and minimize new tooling requirements. So yeah use the same pumps and valves as found on other VW products rather than design a part that is for a single application, particularly for a low volume application.
The incumbents also seems to be waiting to spend until the next stage of battery tech, like solid state are available. Toyota has pretty much admitted to doing so. I would imagine most manufacturers will have the money for EV R&D when they actually deliver the miles people are asking for, as it seems for all intents and purposes that they know lithium and even LFP are limited no matter what you do.
Yeah, I can see that to an extent. I think over time you’ll see EV cooling systems get more elegant across all automakers that are in the market. It just takes time.
Also not sure how much more complicated the Teslas cooling system would be, if it would be aimed for track like the Taycans. Not even Plaids systems handle the continous track use.
My takeaway is that EVs aren’t less complicated than ICE cars, they are just complicated in different ways. Cooling and heating is the underwater part of the iceberg and the place for better engineering. When I see a BOM with lots of valves I immediately envision a modular valve block like the hydraulics on a construction machine and not a bunch of individual valves shotgunned all over the car.
Yeah, that absolutely makes sense.
It feels like automakers are having to make an adjustment. There used to be pretty much just one hot thing that needed cooling – the big ol’ engine. Now, you’ve got to cool one, two, or more motors… the power electronics… the battery…
In order to simplify an EV’s cooling system, it would be a lot easier to do so by simplifying the EV’s battery pack. With LiFePO4 chemistry, you eliminate most of the fire hazard, and it is possible to achieve an internal resistance value so low that you can lessen the need for thermal management and increase peak power even for hypercar applications. Thus, opening up the possibility that the car’s pack is a single series string of prismatic cells, which in turn greatly simplifies both BMS circuitry and cooling.
The major downside of course is packaging. Another one is that you can no longer use standardized off-the-shelf Li Ion batteries that are ubiquitous in consumer electronics. The other cost is a loss of about 20-25% gravimetric energy density.
But just consider that if you want, say, an 80 kWh pack, you could use 800V architecture and have a single series string of 250 prismatic 100AH LiFePO4 cells in series. Finding a bad battery and replacing it would be a much simpler process, than repairing some monstrosity of a pack with thousands of cells each with its own internal fusing and BMS leads, all of which necessitates a complicated network of cooling pipes and systems to keep the coolant flowing in all the places it is needed. You could have a single run of pipes for cooling on such a pack.
I have no idea what you just said, but it sounds great!
How would this have an impact on packaging? By increasing the thickness of the battery pack? (genuinely curious)
Not only is the thickness of the battery pack possibly increased(it will depend upon the form factor of the cells used), but each individual cell by necessity, no matter what dimensions it is designed to have, is going to take more volume than an 18650 or 21700 or 4680 cell, which in turn creates additional constraints on the size and shape of the battery housing that can be made to fit them which in turn dictates everything else about the car’s design parameters.
In cars already produced, like say a Tesla Model 3, such cells may not even fit at all.
Tesla now has 4680 cells in use, albeit they’re still Li Ion. They are 3.6V nominal and 20 AH. If one made a single series string set up for 800V architecture, they could get away with 222 cells in series, as one string, and have a 16 kWh pack weighing 173 lbs. This pack would be great for a minimalist 2-seater microcar designed for minimal mass and aero drag. A CdA value of under 0.2 m^2 with a mass of around 900 lbs would get a 200 mile range at normal highway speeds with such a tiny pack, and it would be small enough in capacity that charging speed wouldn’t be an issue. It would also be very simple compared to the monstrosities Tesla has been building out of 18650s, 4680s, and 21700s(albeit their CATL LiFePO4 Model 3 is similarly simple to what I propose, and they seem to be getting the hint that this is the way to go). You could fit a lightweight axial flux motor in each wheel and make a crazy amount of power for such a light vehicle, bypassing the need for any gear reduction.
I think the range obsession prevents this course of action but we’ll see. Of course, if solid state gets off the ground, that will just change the game entirely.
All the more incentive to ditch the oversized grilles, oversized wheels, creases, low-profile tires, other baroque styling cues, reduce frontal area by making the cars slightly smaller(which could also reduce mass), make the damned things as aerodynamically slippery as possible overall, and ditch CUVs/SUVs for sedans, minivans, and wagons. That would grant a massive bonus to efficiency, which increases the amount of range per kWh of battery.
The 4,000 lb Mercedes Vision EQXX concept gets 6 miles per kWh, thanks to a drag coefficient of 0.17. And this thing is a heavy car, considering they could build a 3,000 lb economy oriented sedan with a smaller battery and slightly less frontal area. Most modern CUV EVs are getting somewhere around 3 miles per kWh for comparison.
Solid state batteries are a game changer even if they were to hypothetically only offer one-third of the volumetric energy density of modern lithium ion batteries. The reason being, is they have the potential to outlast the rest of the car and destroy the fire hazard inherent with lithium-based battery chemistries. Modern lithium ion batteries are around 250 Wh/kg, and LiFePO4 around 200 Wh/kg. In the 1990s, when batteries had gotten up to 70 Wh/kg with Ovonic NiMH, they were “good enough” for an efficiently-designed car packing a 25-30 kWh pack to get real world 150-200 mile ranges on the highway and could be fast charged in under 30 minutes. Everything else after that has been beyond what is necessary, and it has also been squandered on massive oversized vehicles with barn door aerodynamics(at least relative to what is possible).
The problem isn’t the battery pack, but consumer preference.
If battery packs were the size of toasters, manufacturers would still be building big cars because nobody wants ride around in a tiny penalty box.
Consumer preferences are what they are because the bottom 80% are priced out of the new car market altogether. The industry is focused exclusively on the upper 20%.
A good indicator for what the bottom 80% want in a car is to check the depreciation of used cars. The cars that hold their value best indicate what the non-wealthy want in a car. Notice that basic Toyota Corollas and Honda Civics hold their value well. The major automakers almost universally ignore these traits now, because they’re chasing the upper 20% who have money, and trying to extract as much as they can.
If someone were to make an EV that was sufficiently inexpensive that the monthly payment was less than the amount saved on not using gasoline and not having constant maintenance expenses on a clunker 15 year old ICE car, I think it would eventually catch on. Maybe not immediately, but over a decade or so. By necessity, this sort of EV will have a small kWh battery pack, and a low enough road load that it can still get at least 200 miles highway range with that same battery pack. This requires a large amount of mass reduction, feature reduction, and aero drag reduction. In turn, if the solid state batteries that finally get commercialized are low density compared to modern Li Ion and LiFePO4, they could still work for this application.
It makes sense to develop a product for a customer who can afford to purchase it. In general, someone with a 15 year old clunker isn’t buying anything from a new car dealer – it would be a silly plan to cater to them.
Civics and Corollas do OK on the used market. So do Rav4s and CRVs and almost anything except out-of-warranty luxury cars. Used pickup prices show that the used buyers aren’t really too concerned with weight or fuel economy – at least as a primary motivator.
As for the 15 year old clunker guy, I am one. I currently drive a 14 year old car with ~150k miles. I have a short non-highway commute and fill it up maybe twice a month. This was a pretty big maintenance year and I probably spent about $1500 keeping it alive. Between gas and maintenance I’m probably at $225/month. Cars.com’s loan calculator says that is a $10,700 loan.
That’s around what I paid for this current clunker 10 years ago, and I have heated leather seats and enough interior space for four adults and two medium dogs. Locally I could get a 2012 Corolla due for it’s second timing belt around that price or a Rav4 from 2010.
That’s a good $6k less than the cheapest new car – and people generally don’t even want to drive that.
A sub-$11k new vehicle represents a gigantic loss of space, function, features and (likely) safety if that target price is even possible. I would be unwilling to make that sacrifice and I daily drive a Miata in the warmer months. Good luck getting someone out of a Highlander into one of these things.
Over how many months and at what interest?
Someone with good credit taking out a $20k loan over 84 months at 5% interest with no down payment will pay $282.68/mo.
For someone who drives more miles and mostly highway and needs a reliable car for their job, AND if the warrantee lasts the loan term or exceeds it, could potentially be looking at net savings, plus have the convenience/reliability of something new and not have to worry about being bankrupted by a repair bill.
The absolute maximum term anyone should be financing a car, 60 months. 84 month loans are for people buying Mitsubishis with an upside-down trade. Interest is whatever cars.com plugs into their calculator for excellent credit. Who’s offering 7 year warranties outside of Hyundai?
As for highway commute – I’m even less interested in the tiny tube of death for highway use (may as well call it the Blindspot Speed Bump). I’m also not too sold on the reliability of a vehicle from an unknown manufacturer undercutting a Nissan Versa by $6000. The last manufacturer launching a car that way was Yugo (it didn’t go well).
For $20k you can get a real car, and that is what people would buy.
An insulated refrigerator box will probably be very inexpensive to heat through the winter. If you try to sell me one for $400k as an alternative to my house, I wouldn’t be interested.
I think this may be what happens down the road as LiFePo batteries become more energy dense. However, the high power application that Porsche needs is just too demanding for the current LFP offerings
Dude. That’s a turbo.
You misspelled “alternator.”
Yeah, it looked full
It’s complicated and surely can be improved, but I wonder how much is not knowing what we’re looking at compared to a gas car. When I was first learning about engines it was overwhelming to look at all the wires and components, but once you understand the function of everything it begins to make sense.
This is my take as well. I remember rebuilding the entire (very complicated) PCV system on the 1.8t in my ex’s Passat. Lots of hoses, check valves, intake had to come off, etc. It was really daunting at first but once I dug in and figured it out, it all fell into place.
Anyway, in regards to the Porsche in this article…it’s the Germans, of course it’s overly complicated.
I definitely get that angle, but it is in some ways more complex than a gas car’s cooling system. A lot of gas cars have a water pump in the engine block and a single main cooling loop. This car has three water pumps, a ton of valves, multiple motors, electronics units, and a battery pack that all need cooling… in this regard, it is a mite more complex.