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Hypothetically if we have two almost identical cars with identical attributes (horse power, engine size, weight, etc.) , but one of them is front wheel drive and the other is rear wheel drive. My question is:

  • Which car will accelerate, and ultimately go faster?
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  • I think the RWD will have better mechanical grip due to weight distribution and shifting upon acceleration...we'll see what the community says.
    – DucatiKiller
    Commented Jan 27, 2016 at 21:39
  • Is horse power / torque measured at the crank or at the wheels? FF and RR tend to have lower parasitic loses than FR vehicles. If it is measured at the crank, the FF and RR vehicle would have an advantage. Guess that would put us right back where we started though...
    – rpmerf
    Commented Jan 27, 2016 at 22:10
  • Please forgive an ignorant question, I know F = front and R = rear, but I'm not following what you mean by FF, RR, and FR. I have a feeling I'm going to feel really dumb when you tell me.. lol
    – cdunn
    Commented Jan 27, 2016 at 22:38
  • FF usually means front engined front drive, and RR rear engined rear drive. So FR would be front engined rear wheel drive.
    – Karx Marl
    Commented Jan 27, 2016 at 22:47

1 Answer 1

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So two things to consider, acceleration from stopped, and top end speed. And based on your question, the following are identical:

  • Engine horsepower
  • Aerodynamics
  • Gear ratios
  • Tire size

And the only difference is one is a transverse mounted front wheel drive, and the other is a rear wheel drive.

Acceleration from a stop

In this case I think if the two cars have enough horsepower to break the tires loose so they are slipping rather than driving the car forward (doing a burnout), then the RWD would have some advantage. That's due to the weight transfer mentioned by @DucatiKiller in the above comment allowing more horsepower to be applied to the tires without breaking them loose.

Top Speed

For the top end, it's a question of force applied to drive the car forward vs drag. But, there is one more thing that's different between the two. The transverse mounted FWD has a much shorter drive train than the RWD. Same components ultimately (transmission and a differential) just no long drive shaft. Honestly, the amount of energy lost in heating up the longer drive train when compared to the FWD shorter path is negligible compared to the losses in aerodynamic drag. So if I had to bet, the FWD would technically be faster by an amount to small to be measured or matter.

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  • If all things were equal, I'd agree with you on the acceleration part, but on top speed, if aero drag was the same between the two vehicles (ie: all things being equal), neither would win the top speed war. I'm very glad you pointed out this was actually two questions, not a single one.
    – Pᴀᴜʟsᴛᴇʀ2 ♦
    Commented Jan 27, 2016 at 22:08
  • I disagree on the acceleration part. The front wheel drive car would have more of the weight over top of the drive wheels, 70/30. The rear wheel drive car is split roughly 50/50. If the weight of the two cars was the same then the front wheel drive car would have more traction.
    – vini_i
    Commented Jan 27, 2016 at 22:15
  • If I understand correctly when the car accelerates the weight of the car distributes itself to the back end of the car. Correct me if I'm wrong, but since the RWD car has more weight back than the FWD car, the RWD car has more contact (so to say) between the tires and the surface so it'll propel itself much easier just like @DucatiKiller said.
    – Karx Marl
    Commented Jan 27, 2016 at 22:26
  • I think a lot of this depends on just how much horsepower the two cars have. If they are powerful engines and tires that grip well there will be a lot of acceleration and there will be a lot of weight transfer to the rear wheels. Maybe or maybe not enough to overcome the cars front to rear weight ratio. If the cars are like my 2000 Toyota Camry even with both chipmunks running as fast as they can there won't be much acceleration.. lol So, I think we would need to define things a little more because @vini_i has a really good point, in the FWD the weight is already on the wheels.
    – cdunn
    Commented Jan 27, 2016 at 22:34
  • So, if @KarxMarl is ok with it, lets break down the acceleration from a stop into two more cases. Case 1: the FWD car has a 70/30 front to rear weight ratio, and the RWD is 55/45. The horsepower available to both is measured at the crank and is 120 BHP. In case 2, same front to rear weight ratios, but the engines produce 350 BHP. In both cases the cars weigh a total of lets say 3500 lbs. This is a great thought question, love this!
    – cdunn
    Commented Jan 27, 2016 at 22:51

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