Cars

[DodgyAgent]

[Dark Black]

I don't know about VW but most Audis are full time 4WD with a Torsen centre diff.

I thought the TT was only part-time 4WD?

[gingerjedi]

I see dodgy is busy making money.

[doodab]

I thought the TT was only part-time 4WD?

Yes apparently the TT & A3 are, but most of them are full time 4WD with a torsen diff.

[Dark Black]

Yes apparently the TT & A3 are, but most of them are full time 4WD with a torsen diff.

Fair enough... i always thought part-time 4WD (controlled by the car and not the driver) was a stupid idea anyway.

[Mich the Tester]

What do people think of volvos?

I think of them when I want to get rid of an inconvenient erection.

[Old Hack]

Get a car with over 300 lb-ft torque, and try launching it from standstill. The 4WD will take it without flinching, the rwd might slide it's rear end a bit depending on the state of tyres, and the road conditions. The FWD will then start showing signs of torque steer. You will feel like you have to grip the steering wheel tightly, otherwise the front wheels will make it wobble. It's true that many modern FWD cars come with factory fitted LSD, but that helps more in cornering and keeping traction when you come out of tight bends. Essentially, LSD allows 2 wheels to spin at different speeds, which helps on twisty roads.

Normally, a powered wheel will take the path of least resistance, so if you have one wheel parked in wet mud, or grass, it will light up, whilst the other wheel doesn't move an inch, as all power is being given to the spinning wheel. An LSD actually provides the power to the wheel with the most grip. Then you have 4WD which can have diff locks, which essentially ensure both wheels turn at the same speed; great for off roading, rubbish for on the road, as the axles suffer what is called wind up.

I don't know about VW but most Audis are full time 4WD with a Torsen centre diff.

Correct; they have a pukka 4WD system whilst VW use an electronic part time 4WD.

I thought the TT was only part-time 4WD?

They made the TT is lower power FWD, but otherwise, they have full time asychrobnous 4WD

Yes apparently the TT & A3 are, but most of them are full time 4WD with a torsen diff.

Not the TT, although the very latest one doesn't use a torsen diff, it uses a new carlos fandango one, apart from the Q7, which still has the torsen. It also has electronic diff locks.

The 4Motion system is slightly different, in that the ones that have a longitudinal engine (N-S), have a torsen diff, and transverse engines (E-W) have a haldex clutch differential which unlike the torsen, can be electronically controlled, so that you only get 4WD when you really need it. It's actually a brilliant bit of kit, saves gas, saves tyres, and emissions.