FWD vs RWD

[Tumbo]

Originally Posted by siko

If you have to add two more suppositions:
* Same tyres
* Optimal weight distribution for each platform (ie 50/50 for RWD)

... then for sure RWD.

Why is that?

P.S. AWD is not mentioned in this question at all.
I just want to know which of FWD and RWD is faster.

[Michael]

I would say RWD. Of course like many others have mentioned there are so many variables that play into this.

But basic physics, at least what I have heard, is that when the inertia is sent back meaning the power is forcing the car to slant back, this puts more traction, by a small percentage on the back wheels. Meaning if it were a RWD then it would be delivering a little bit more power because the wheels are being cemented onto the floor. As in a FWD car the force does the same and therefore lifts the front up causing it to not put as much power down on the ground as one would think.

Like some of you have mentioned. AWD is very different. If you were to put an AWD car vs an RWD car like the S4 vs. M3. you will see that the S4 will have a faster start because of the AWD and the grip it has. It is as though some is pushing in the back and someone else is pulling in the back. But then where there is momentum the M3 catches up and passes the S4 (not by a lot)

[Carbon]

In some cases, FWD might be faster with the weight of the engine over the driven wheels (assuming it isn't a Porsche or something). I still think the two would be extremely close with the advantage probably depending on the car itself.

[dOmInIX]

I'd go with RWD because of fun!!

[martinbo]

In theory, regarding cars of like output and weight with identical tyres, RWD will invariably negate the FWD's advantage of less drivetrain mass and friction with it's superior traction under acceleration. Just like BMW said, as a vehicle accelerates weight is transfered to the rear axle which improves grip dramatically and hence tractive acceleration.

The RWD car will be quicker.

[donau]

Originally Posted by martinbo

In theory, regarding cars of like output and weight with identical tyres, RWD will invariably negate the FWD's advantage of less drivetrain mass and friction with it's superior traction under acceleration. Just like BMW said, as a vehicle accelerates weight is transfered to the rear axle which improves grip dramatically and hence tractive acceleration.

The RWD car will be quicker.

I believe so too. And obviously a RWD car with the engine sitting on top of the rear wheels will have an advantage to a RWD front engined car. What about a RWD mid-engined car?

[Tumbo]

Originally Posted by martinbo

In theory, regarding cars of like output and weight with identical tyres, RWD will invariably negate the FWD's advantage of less drivetrain mass and friction with it's superior traction under acceleration. Just like BMW said, as a vehicle accelerates weight is transfered to the rear axle which improves grip dramatically and hence tractive acceleration.

The RWD car will be quicker.

Thanx.

[ojis]

I still think that the FWD car will win in most cases. You'll need a helluva poweful engine if you want to lose traction at 100 km/h so traction is not the issue here. Also a FWD car weights roughly 30kg - 40kg less than a RWD.

[Snake Vargas]

Originally Posted by martinbo

In theory, regarding cars of like output and weight with identical tyres, RWD will invariably negate the FWD's advantage of less drivetrain mass and friction with it's superior traction under acceleration. Just like BMW said, as a vehicle accelerates weight is transfered to the rear axle which improves grip dramatically and hence tractive acceleration.

The RWD car will be quicker.

Hi everyone. Sorry for dredging up an old topic, but over the past ten days (almost 2 weeks?) or so I've been in Hong Kong, and then away in the mountains for a bit..

Anyhow, would the extra traction from the RWD's weight transfer to the driving wheels only matter if traction was going to be broken in the FWD car? For example, if the cars in question only had 25kW and 50Nm and weighed 1000kg (sure, no car does, probably, but for the purposes of the theory).

I am of the opinion that, in that case, and ignoring driveline inertia, neither car would have any particular advantage.