Rear-wheel-drive and all-wheel-drive cars are common enough these days, but the front-wheel drive configuration is the most popular drivetrain layout bar none. The transverse front-wheel drive layout, that is. But what about front-wheel drive with a longitudinally-mounted engine? Could such a thing even exist?
Once upon a time, rear wheel drive cars were simply the default. You had the engine in the front and it sent power to the back wheels. But then engineers started optimizing for things like legroom and cargo space, and everything changed. Front-wheel-drive cars started to take off, with transverse-mounted engines used to maximize space for passengers and cargo. The benefits for the customer were undeniable, so the design took the mass market by storm.
Thus, you might think that every front-wheel-drive car out there has a transversely mounted engine. Take a sample of just about any parking lot, and your assumption would be reaffirmed. But it would be wrong—for a slim number of longitudinal front-drivers do exist!
Longitudinal Story
First things first, what do we mean by longitudinal layout? Well, we’re talking about a car where the engine is mounted such that its driveshaft is aligned with the long axis of the vehicle (i.e. front to back).
The longitudinal layout, also known as “north-south,” makes perfect sense for a rear-wheel drive platform, as the transmission sits directly behind the engine, and then sends power to the rear wheels via the driveshaft.
In contrast, most front-wheel drive cars use transverse layouts, also referred to as “east-west.” This is where the engine’s driveshaft is perpendicular to the long axis of the car.
This layout is prized for its compactness, as it’s easy to fit a compact transaxle onto one side of the engine to drive the front wheels. Designers can create a very short engine bay with this layout, providing more room for passengers and cargo for a given size of vehicle.
Given the transverse layout makes so much sense for front-wheel drive, seldom few vehicles go the longitudinal front-wheel drive route. Perhaps the only main benefit is that the layout can provide better lateral weight distribution, with the engine mounted closer to the centerline of the vehicle. In contrast, transverse layouts often have the engine mounted significantly off to one side.
Another benefit is reduced torque steer. With an engine and transmission mounted more centrally in a longitudinal setup, equal-length half-shafts are easier to implement, reducing torque steer greatly. It can theoretically make it easier to fit larger engines, too, though the combination of big engines and front-wheel drive is a rare one. It’s ideal for very wide engines, though, like boxers, or 90-degree V engines.
Meanwhile, the drawbacks are usually pretty obvious. You tend to need quite a long hood to fit a longitudinal FWD setup. You can also get a lot of understeer if you have the engine mounted a long way ahead of the front wheels. Alternatively, you can have the engine behind the front wheels in more of a mid-mounted position, but this will intrude on cabin space.
The Oddballs Among Us
It’s a a weird layout with few benefits, but that hasn’t stopped a wide variety of automakers tinkering with longitudinal front-wheel drive. Some of these vehicles you’ll find surprisingly familiar, others are more obscure.
Saab is perhaps the best known for its longitudinal FWD vehicles, which place the engine towards the middle and the transmission towards the front. This covered a great deal of the company’s models, from the 1960 Saab 96 to the 1994 Saab 900. The company eventually abandoned the idea in the mid-1990s, switching to the more common transverse layout.
This layout was also famously used by the Citroen Traction Avant, often referred to as the grandfather of front-wheel-drive. The Traction Avant had its engine mounted far behind the front axle line. The transaxle was bolted in front of the engine, which then sent drive to both front wheels.
In contrast, some automakers elected to put the engine up front, ahead of the transmission. Audi is a particular fan of this layout, and you’ll see it even on modern cars like the FWD versions of the A5. This layout can be particularly advantageous for vehicles that also have an AWD variant, as it makes it relatively simple to send power to the rear axle.
Subaru also effectively implements this layout in its FWD models. After all, the width of the company’s boxer engines would make a transverse layout impractical and ugly. It also maintains commonality with the company’s all-wheel-drive models.
You’ll find a similar layout in vehicles like the Renault Fuego and the Renault 21. In the latter case, Renault actually built models with smaller engines with transverse FWD. However, the company’s transverse gearboxes weren’t up to handling the greater torque of the company’s larger engines, and so those with the 2.0-liter used a longitudinal FWD layout.
@fastlanejezza Renault 21 Engine Layout ⚙️ #fastlanejezza #renault #renault21 #engine #renault21turbo #renaultengine #renault5 #renault5engine #enginelayouts #midenginerenault5
The beloved Oldsmobile Toronado fits into this category, too. It had a monstrous 7.5-liter V8 engine with the transmission mounted on the back and underneath the engine. It sent drive forward to a differential mounted directly under the engine, driving the front wheels.
Much the same was done on the second- and third-generation Honda/Acura Legend. Despite being front-wheel-drive, these models had long hoods and overall proportions more befitting a rear-wheel-drive layout. In the engine bay, Honda paired its C-Series V6 with a rear-mounted transmission, which fed a differential underneath the engine block.
Ultimately, you won’t find this layout in cheaper, smaller cars. By and large, it’s too space inefficient for such applications, and doesn’t provide much benefit in return. However, it’s still finding use in larger, luxury applications. It’s particularly useful for automakers that want to sell models with a longitudinal AWD drivetrain with a reduced-cost FWD version as well.
Hopefully, now, you find yourself duly educated on this obscure layout. Next time you see such a car out on the road, you can tell your friends about how it’s got a longitudinal FWD drivetrain and why that’s strange. Though, if they’re not car enthusiasts, you’ll probably need to explain the whole thing from the beginning. Feel free to point them to this article if so.
[Ed note: The first V4 Ford Taunus was also front-drive longitudinal engine, as was pretty much all two stroke DKWs. -DT/JT/Matt]
[Second ed note: As SWG and some of you lovely commenters noted, we should not forget about the Chrysler LH Cars!
Front engine V6, front-wheel drive! -DT]
Image credits: Audi, Saab, Oldsmobile, Citroen, Honda, Lewin Day, TTTNIS, JDM Auto Parts USA, Diagrams – Jason Torchinksy
I have owned 4 longitudinal FWD cars:
Citroen GS
Alfasud (2 of them)
Renault 5.
In addition, my father owned a Renault 16.
Lovely top down view of the Renault 12 in the layout examples 🙂
Was just gonna mention the Chrysler LH cars… which have their design roots with the AMC/Eagle Premiere.
Along with the LH cars and Premiere, the many other larger Renault models had the same layout.
And remember the Citroen Traction Avant? That car along with all the other older Citroens like the 2cv and also had the same layout.
Longitudal FWD isn’t rare at all.
Has there ever been a transverse flat/boxer engine? I guess maybe an oddball 2-cylinder, but it seems only logical they would all be mounted longitudinal.
I used to own the exact Saab in the cut away. I miss that car every day.
Mercedes-Benz’s first FWD passenger car (W168, A-Class) has a transverse-mounted engine behind the front axle. The engine is tilted forward at about 30° angle with differential gear and driveshafts closer to the cylinder head than in line with the oil pan or crankshaft. This set-up allows the whole engine and gearbox to slide down out of the way instead of into the passenger interior during the frontal collision.
Mercedes-Benz abandoned this unique set-up for the third-generation W176 A-Class, which uses the new MFA-platform that retains the popular configuration of mounting engine in upright position ahead of front axle.
I spent some time in the Chrysler LH cars and while I can’t speak to the overall quality, especially in the long term, I liked the looks and found them delightful in terms of comfort back in the day. But yeah, we didn’t really know it was that layout until we rented one and had a look under the hood to check the oil.
A good example of the improved packaging efficiencies of transversely mounted engines is the Saab 9000. It had a longer wheelbase and increased interior space compared to the 900 despite being shorter in overall length.
Saab 9000 – Wikipedia
Very interesting. I didn’t know there were configurations with a transmission up front. Cool!
Now, when it comes to longitudinal FWD engine the ones I remember the most were the ones used in full sized GM luxury coupes, Audis, the LH cars and Subarus.
I’d say for V configuration and H configuration engines it makes total sense. You really want to be able to replace your spark plugs with ease.
There were also the Triumph 1300 and 1500 saloons, with the gearbox under the engine.
Lest we forget! The 1982-88 Toyota Tercel!
…and to be clear, ALL tercels of that generation. Not just the 4WD variant championed by Santa Claus when new and methemphetamine enthusiasts in New Mexico 30 years later.
Don’t forget the first generation, L10, from 1978 to 1982!
1979 – 85 Riviera/Toronado/El Dorado were pretty common on U.S. roads.
Millions of Subarus with this layout…
Aren’t those AWD, not FWD?
Up until 1999, the Legacy was available in FWD as well
Fully 1/4 of the cars I’ve owned have been longitudinal FWD – 2xLeCars, a Traction Avant, a 2CV, a Saab 900, and a Lancia Fulvia. They seem pretty common to me.
It also bears mentioning that the DKW layout was the basis for the Audi platforms, some of which were adopted by VW when Volkswagen acquired Auto Union. The B1-through-5 and BX (Brazilian) platform, of which you may know the Passat, Fox, and Gol (not Golf), were built on the same longitudinal layout, and some BX variants (the Gol included) even got the Beetle’s air-cooled flat 4, sipping ethanol through twin carbs in some trims!
Also, it’s my understanding that the Renault 5/LeCar has the longitudinal drivetrain taken almost straight from the Renault 8, where it’s rear-mounted. Unlike Volkswagen, who flipped it over to put the engine out front, Renault just kept it exactly as it was.
2CVs are longitudinal FWD.