I can’t really remember exactly why we were talking about it, but for whatever reason David and I ended up talking about front-wheel drive layouts. I think it was triggered by the realization that the Dodge Intrepid was a longitudinal FWD design, which, buy modern standards, is pretty unusual. That, of course, made me think about other longitudinal FWD cars, like Audis and Citroën 2CVs, and then the other kind of longitudinal FWD, where the transmission is in front, like Saabs and Citroën Traction Avants and and Cords. Anyway, it got in my head, and the only way to exorcise thinking about this is to rope all of you poor bastards into it. So, with that in mind, now I’m curious and desperately want to know this: do you have a favorite FWD layout?
Here, let’s walk through all of the FWD layouts I can think of; I tried to include all of them, including at least one that I don’t think has ever been tried, because of stupidity. So, here we go, time to evaluate and see what grabs you, deep and tight:
Okay, these two transverse-engine versions, just mirror images of one another, are by far the most common FWD layout – and, most likely, the most common drivetrain layout of any kind on the road today. I suppose the original Mini is a bit different, in that it has the transmission below the engine, but it’s pretty much like these. Their biggest advantage is most likely packaging; it’s a really compact and space-efficient design.
This layout is perhaps most commonly seen now in Audis, and lends itself well to having all wheel drive variants. It does push the engine very far forward, making the car pretty nose heavy, but there are plenty of great-handling cars that use this method despite the seemingly very understeer-y layout. It’s less space efficient than the transverse version, but you still don’t need a driveshaft, so it’s not too bad.
I always liked this sort of layout, probably best known in Saabs, because it forces a front-mid engine layout, which I’ve always been a fan of. It also lends well to a sloping hood and easy transmission access, though getting to the spark plugs on the rearmost cylinders can be tough.
Okay, those are the mainstream options. Let’s look at the weirder stuff:
Now, this just seems bonkers: rear engine, front drive. This seems like a layout specifically designed to find the worst qualities of every layout: you still need a driveshaft, you have to deal with rear-engine oversteer, and you get none of the traction benefits of putting the engine over the drive wheels. There seems to be zero reasons to try this, yet it has been tried a few times! Never successfully, but I did once catalog all the loons who tried this for The Old Site:
Why do this? I have no idea. Maybe some kind of latent distaste for rationality, I get that. I suppose you could also do this with the transaxle up front:
Would that be any better? Maybe a little, but not much. At all. It’s still ridiculous. I suppose technically the Dymaxion may have actually been rear-mid, front drive? Oh jeez. Fine, let’s make one of these for that absurd layout:
I’m not making a transaxle front version of this, though, because it’s never been done since, you know, it’s just that stupid. It’s got all of the problems of the rear-engine/front drive layout, but with worse packaging. It’s kind of achingly beautiful, in that miserable way.
Okay, one more weirdo, this one was actually attempted:
The legendary T-Drive! This was a design attempted by Ford to accomplish something I can’t imagine anyone actually asked for: shoving a straight-eight engine transversely in a Ford Tempo.
They did manage to do it, by tapping power from the middle of the crankshaft instead of either end. It’s bonkers. If there was a good reason to do this, I can’t figure out what it might be. But I’m glad they did it?
Everyone got all of these? Take a moment to really consider which one moves you the most. Technically, emotionally, erotically, all of it. Time to vote!
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Would the classic Saab 900 (and presumably the 99) really count as a transmission forward FWD? While the engine output, clutch, and flywheel does face the front of the car, the transmission itself sits under the engine and serves as the oil pan, with a chain connecting the two.
https://sweedspeed.com/wp-content/uploads/2020/10/IMG_4936.jpg
Interesting. Does changing engine oil also change transmission fluid? Or are all the gears of the transmission kept out of the oil pan?
No, the two don’t share oil, the top of the transmission is closed off from the engine. But interestingly enough they both require the same 10W-30 oil (on manuals that is, automatics may be a different story).
RWD is my favorite form of FWD.
Transverse. If you are going to go FWD, might as well just take the packaging efficiency and move on.
Hey, those diagrams for the transverse front wheel drive layout look completely screwy to me. All of the examples that I am familiar with have the drive axles come from the differential which is located between the transmission and the engine with none of that crazy dog leg stuff. Mostly the drive axle is to the rear of the engine although I think there are some cars with the drive axle in front of the transverse engine.
At any rate, I’ve never ever seen that crazy dog leg stuff.
Those are terrible diagrams.
I skipped past them, but now you’ve pointed it out I’ve lost a tiny bit of respect for Torch. I’ve still got loads left though, don’t worry.
I’m sure that a correction is on the way, plus it’s an opportunity to dive into why Honda engines spun backward until they switched the side the transmission was on.
I’ve owned three of those layouts despite only having owned 4 FWD cars (I’m counting all three CRXs as one here).
I guess for a favourite I’d have to go longitudinal in front of the gearbox. Normally induces front-heavy understeer, but not if it’s a 602cc air-cooled flat twin, nothing heavy about that engine.
My favourite layout regardless of drive location is mid-longitudinal straight six RWD like the BMW M1 and nothing else I can think off. I guess it’s a waste to have room back there for a V12 and only fit half of it, but I like straight sixes.
I just remembered: I worked on an EV with front hub motors, which isn’t any of those layouts, and also a REEV with transverse electric motor and gearbox but a longitudinal ICE with a generator on it. Neither of those made it beyond a single prototype though, because one has issues and the other one was just stupid.
If we’re including EVs then transverse twin front motors driving a wheel each is the daddy.
Lamborghini Marzal, but that wasn’t a production car.
Oh, but you forgot one!
How about the longitudinal engine with a torque converter behind the engine connected by a chain to a automatic transmission beside the engine with a differential in front of that?
I think that is how one would describe the Oldsmobile Toronado and Cadillac Eldorado drivetrains. Did right hand axle go through the engine on those?
No, the axle did not. They used an oil pan with a shortened sump that allowed room for the axle to pass beneath it.
https://www.classiccarsseller.com/media/uploads/cars/2019/1/12/1978-cadillac-eldorado-brownbrown/10.jpg
Though I seem to recall there was some AWD variant of some car, (I want to say a Mercedes?) that had the axle go through the oil pan?
BMWiX. Miserable to do anything on. (Meaning more miserable than the average on a BMW).
Longitudinal, transmission behind. Because I’ve been in love with the ’66 Olds Toronado forever.
Going with the longitudinal, engine front layout from experience with my ’88 VW Fox. I’m always surprised at how much fun that is to drive for a fwd car.
The first time you replace a clutch in a SAAB, your life will change. Maybe that’s a dumb reason to pick a layout, but it’s mine.
I agree there is a certain satisfaction to be derived from lifting the whole engine out of the car for a clutch job, then reinstalling it, all with just one’s bare hands, but I don’t know that I’d call it life-changing. They are also easy to carry over to the trunk for storage, though:
https://live.staticflickr.com/8434/7504752768_c75413ff59_c.jpg
Did anything do a Toyota previa but with the drive running forwards? No obscure Japanese vans?
Liked the layout of my ‘86 SAAB 900T the best. Thirty years and 500,000 miles with nary a hitch.
It may not be the most advanced, but I can tell you why transverse with the gearbox on the left is fun in the A112. Empty, 62% of the weight is at the front, 51.5% of which is on the left wheel. Add the driver at 85 kilos, then make an extremely aggressive right turn in race mode, and you shall be turning on three, or possibly even two wheels without tipping over.
My Renault 12TL was longitudinal rear tranny and it did have a rather over-bitey demeanor. And it understeered quite a bit, but pretty much all early FWD cars did.
To this day, it is one of the few cars I have made money on. It was totaled in a snowstorm and the clueless insurance paid me way more than I had in it. Then I bought it back for $200 and drove it 2 more years!
The Audi-esque layout is my favorite as far as FWD goes, because it’s easy to make it AWD or RWD from there, since everything is facing the correct direction anyways. Therefore it’s the lesser of the evils (the evils being FWD in general).
True, but the old ones had a flaw- the motor was shoved so far forward that the radiator had to be pushed off to the side, reducing it’s size and leading to overheating issues.
(former 5000 owner speaking from ‘sperience)
I know it’s terrible for cooling, but the radiator next to the 5 cylinder engine layout is so cool-looking. Reminds me of a time before engine bays got homogenized— everything is a 2L-ish turbo 4 nowadays, yawn.
I mean, rationally, the obvious, common solution is best. BUT that T-drive.. man, I had never heard of it but it wins hands down for effort.
It’s Renault 4 time again and I’m quite proud to have been the owner of two almost mid-engined (well, front-mid engined) cars in my youth! 😀
The spark plugs were no issue, plenty of space to wrench on the engine as the engine was small and all the parts were accessible for a shadetree mechanic I was at the time.
Bought the first Renault 4 out of spite because parents said I’m not allowed to and I’ve bought the biggest POS on the road. Sold it for a very minor loss in a month.
My second Renault 4 I bought from my father with 275.000 km and took it to 400.000 km with no issues. Sold it to a colleague of mine and he promptly put in a ditch where it fell appart… probably even before landing 😀
I’m partial to the longitudinal/transmission-in-front, and can provide evidence via my past ownership of a Saab 900, Traction Avant, and two LeCars.
This article needs more Cord.
What does the UR Mini count as ? bonus points for sharing engine oil with transmission
does koenigsegg gemera count for the rear engine, front transaxle?
Gimme the T-drive, cause when I want to have to change the clutch or torque converter I REALLY wanna get upset at someone.
Longitudinal, transmission in front, for the reasons you provided and because SAAB. I feel like it subtly enhances the handling without all the compromises of, say, an H4 engine configuration.
Always SAAB. Mic drop
My Citroen DS, Renault 5(s) and R16 had the transmission-in-front layout. Decent traction, easy to work on (aside from pulling the engine, which meant the gearbox had to come out first, but they were fairly lightweight), nice weight distribution and, best of all, equal-length driveshafts, which basically eliminated torque steer.
As a bonus this setup made room to carry the spare tire up front, which was good for trunk space. At least that worked until the elastic strap that held the spare in place wore out. After that, Bungee cords.
One great joke was if the mechanic was not aware that the first oil screw from the bottom was for gearbox oil and the second was for engine oil. There were some surprise gearbox oil changes and a lot of laughs, but lessons were learned 🙂
I currently have one example each of transverse, transmission right (Austin Allegro, although, as noted for the Mini, the transmission is under the engine); transverse, transmission left (Austin Maestro); and longitudinal, engine front (SAAB 96). They all regularly need work and, in these applications at least, the SAAB’s configuration is the easiest for the widest range of engine and transmission work, so it’s my favorite. I’d certainly be willing to try the other configurations, though.
2nd the SAAB transmission under the engine, clutch in front. While it makes clutch replacement easy, transmission repair and pinion brg/pinion gear & shaft replacement are a bit tougher. In the USA, transmission left helps balance the weight of the driver on the left. In Japan and the UK (including Australia), trans on the right is more logical.
Well, no, mine’s a 96. The engine is entirely in front of the transmission, with the clutch in between, as shown in this example that’s much, much more presentable than mine:
https://journal.classiccars.com/media/2021/09/saab-96-5-2-768×562.jpg
V engines should be longitudinal, inline engines should be transverse.
Anyone who has changed the back bank of spark plugs in a FWD V6 will agree.
As former owner of a Cadillac with a transverse HT 4500 V8, I can’t argue.
Inline 6 in BMW and all the other serious cars are a beautiful example of longitudinal perfection 🙂
Inline 4? Well, that would just look wrong longitudinal… until you get to Mazda Miata (and you always get to Mazda Miata, of course) where it represents perfection again 🙂
Ok, but those cars are RWD
Or had to deal with exhaust manifolds. And if any studs are going to break, they’re going to break on the rear bank of cylinders.