carla

sorry for my ignorance but is it possible for quattro to not fuvtion and is there a way to find out if the 4 wheel drive is functioning?? thanks guys!!

Denver J

quattro always works... it's a true FT AWD system

more

if you have a manual transmission the quattro doesnt "work well" with the clutch in.

DavidG

The front-to-rear torque distribution is strictly mechanical via a Torsen differential. This part of the system functions full-time, and it would be hard for it to fail unless you find your car on blocks and the drivetrain stolen :-)

However, the left-to-right torque distribution takes place using the ABS system to apply selective braking. This part of the system only works at speeds below 18 MPH (from what I've read on other postings in this forum). Below 18 MPH, it is also a full-time system, with no user intervention required. I suppose that this could fail if the appropriate electronics failed (although, since this is tied into the braking system, I'm sure it's designed to be quite robust).

DaveL

you will hear very little of the tire spin heard in FWD or RWD cars. What spin you do hear is momentary as the torque from the spinning wheel will then transfer to other wheels.

It is an amazing system, but remember that the traction you get is only working under throttle. If you are off throttle and coasting into a turn you really have no better traction than any other vehicle on the road. Road adhesion in that scenario is mostly related to the speed your going and the adhesion limits of the tires.

In other words...don't let quattro raise your confidence level too much because it really doesn't help you brake or turn better than a 2wd car.

Just some friendly advice because I don't like to see fellow A4 owners in ditches. ;-)
Dave
'97 1.8TQMS Wett

wheels? (Greg Davis 99.5 2.8 QMS)

whoah, you lost me there. Are you saying that above 18mph, 1 front and 1 rear are the only pulling

JayP

Under engine braking, quattro is more balanced than a front driver. Just like acceleration, the load goes to all 4 wheels. If you engine brake too much with a front driver and go too deep into a corner you'll get push. With rear drive you'll throw the rear out.

With quattro you can get back on the throttle a lot sooner after the apex, even before! If you add 40 feet to the straightway you'll have a higher top speed.

Both situations deal with engine load. Push the clutch in and you're in the same dynamic as 2wd cars.

(Professional driver on a closed circuit.)

Jason H

Below 18mph your torque split for the rear wheels for example, could be 70% right, 30%
left. But above 18 mph it is always 50/50. So under 18, you can have any arrangement that
adds up to 100%

example:

LF - 35 RF - 65

LR - 23 RR - 77

But over 18 it can only adjust front and back:

LF - 30 RF - 30 (30% here as a SET L&R)

LR - 70 RR - 70 "

or:

LF - 55 RF - 55

LR - 45 RR - 45

jason s.

let's say this a4 lasts for 15 years, how will you be able to tell if the quattro ever fails? as well, when the system isn't engaged over a very long period of time, does anything bad happen to it?

yeah yeah, i know...pretty weird questions. but i was just wondering.

jason
98.5 a4tqs tip

Andy Hedin

<i>...as well, when the system isn't engaged over a very long period of time...</i>

Quattro is always "engaged". It's a full-time all-wheel drive system....it's not like the four-wheel drive on some trucks were you have to actually engage the system via a button, lever, etc.

Andy Hedin