Oo hoo - nice contentious topic Artist.

There are a great many misconceptions about AWD and the benefits it provides.

monster is right, AWD drivetrains have more components: 3 differentials instead of one, two propshafts and two extra driveshafts in its simplest form. In essence, some of the power produced by the engine is consumed by the rotational masses and frictional (more gears, more teeth, more friction) losses know as driveline drag. In effect this means that a car with AWD is less efficient at putting power to the road - especially at higher speeds than a two-wheel drive car. This is a primary reason why the best supercars are rear-wheel drive and why a car like the Veyron needs 1000 horses.

All-wheel drive cars are only faster off the mark if the driver pulls away:
a. without bogging the engine down
b. without slipping the clutch

It must be noted that for the optimum launch in any car just the right amount of wheelspin needs to be generated to avoid bogging the engine down. It's simple: too little wheelspin and grip on the surface overcomes the engine torque, too much wheelspin and you waste valuable seconds trying to grip the road enough to translate into meaningful forward acceleration.

There are several ways to launching an all-wheel drive car for optimum get up and go:

a. A the clutch side-step method. Get the revs up to around 5500 rpm and slide your foot leftways off the clutch. [Wince] Here the idea is to "shock" the tyres into letting go for just an instant so that all the engine power can be translated into forward motion without getting bogged down. The problem with this method is that one can smash first gear and/or its synchromesh to smithereens or, if the torque does somehow make it past the transmission, then the centre and rear differentials take up all of the driveline shock and they can end-up being a little less than "round". A little bit of wheelspin is thus essential. If not then this has to be the most mechanically unsympathetic launch method, it sounds terrible and makes the most awful "BDWANGGG" sound. The preferred method for launching an RS4 quickly.

b. The handbrake-friction point method. Getting the revs up to around 4000 rpm hold the car using the handbrake whilst simultaneously engaging friction point. Stomp on the gas, drop the clutch and the handbrake in one go and hey presto. Burns clutches quicker than Grandma burns the chips if done by an amateur. Preferred method for launching EVOs and STIs.

c. The auto-tranny two footed pullaway. In performance cars with a high stall speed torque convertor automatic hold the car with the left foot on the brake and dial up the rpm. Release the foot brake and mash the accelerator to the carpet. A fine way to break an automatic transmission if not done with a measure of precision and mechanical circumspection. NOT recommended for DSG's, SMGs and CVTs.

In more cases than not the AWD driver actually loses out to a less powerful two wheel drive car because they didn't dial up the right amount of rpm and ended up trying to race off 3000 rpm.

The same will apply to FWD vs RWD, the FWD system being slightly more efficient in terms of placing the maximum amount of power at the wheels. This is oft negated by the poor traction on the front wheels from pullaway as a result of weight transfer to the rear on take off and the diminished available grip on the front wheels.