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Why the distance between the end of the front fender and the starting point of the front door of a vehicle is different in RWD and FWD cars?

I am talking about the gap marked with red in this pic: https://goo.gl/photos/GkSaasZ21h2h68eU7

This applies to maybe 98% of the cars I see on the roads, so I find it interesting. At first everybody says it's a question of design or something like this, but when you start looking at the cars that pass, you see that there is something.

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This is a little of an opinional answer (because I don't have any solid source for this), but I think it comes down to two things:

  1. The orientation of the transmission is generally different. In many (if not all) FWD vehicles, the transmission is positioned horizontally (parallel to the bumpers and axles), where as in RWD vehicles the transmission is generally oriented vertically (perpendicular to the bumpers and axles). This of course pushes back where you can have the cab space begin.
  2. Weight dispersion would probably be the second main reason. Depending on a number of factors (math and laws primarily), the engineers may need to push or pull the location of the motor and trans. This of course depends on a lot of design elements, but could basically come down to where they want the weight sitting.

As Solar Mike mentions, this will also vary depending on the purpose of the cars' design (utility vs race for example) of course, but I think a large part of that will be forced because of the size and orientation of everything that they have to fit in the engine compartment.

Another interesting point of not is how this fender/door distance is also increased with older cars and cars that just had huge motors and were RWD. This creates a huge distance between the front wheel well and the door because of how long the engine is. Rolls-Royce 100EXenter image description here

  • I think this sums all. Weight distribution and the fact that the FWD cars have their gearboxes not behind the engine but next to it. So it would be better if the engine is exactly on top of the front axle. – user3687808 Aug 22 '17 at 6:35
  • And handling re component location for a 50-50 weight distribution? – Solar Mike Aug 22 '17 at 13:09
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It is different because of the purpose of the vehicle, the ground clearance required, the type of vehicle : sports car (think old...), sedan / coupe, suv, pickup etc as the sitting position changes for driver and passenger : more upright means leg space tends to be shorter, more reclined has more length for the legs.

The front or rear wheel drive also has an effect as the "nose" of the car needs to incorporate a transmission and differential on a FWD. Mind you the mini designed by Sir Alec Issigonis was a superb solution...

A RWD does not have those constraints and some designs were not based on frugality of fuel consumption either....

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