Snow Chains in Audi A6 Quattro

Quattro is not a 4 X 4. It is an all wheel drive system - very different.

If you *must* use chains, they should go on all four corners. However, I live in snowy New England and have never had the need for chains with Quattro AWD. You can go just about anywhere with a good set of tires, but stopping can be a problem. Therefore, I recommend good snow tires on all four corners. You'll go anywhere you want, and you'll be able to also stop. Put studs on the snows and you can live atop Mt Washington......... well 2/3rds of the way up, at least. d;o) Dave

With AWD, you really need all four tires to be the same. If you want chains, then they should go on all four wheels. For most conditions (other than ice) a good snow tire should be adequate.

The specification that chains should never go on the front alone is correct

-- you NEVER want the rear wheels to have less traction or cornering force than the fronts, otherwise the car will spin out much too easily. For the same reason, you should always keep the tires with the greatest tread depth on the rear, not the front.

anachronism,

Hear hear! I thought I was they only one knowing that the best tires should be in the rear. Now I know there's at least someone else.

Ronald

R@L schrieb:

Can you elaborate?

Why would it be better to have less friction in the front on a front driven car? That supports understeering, doesn't it? The rear wheels just roll along. What's the error here?

Regards

Wolfgang

If you have ever tried to break hard, really hard, with badly worn tires at the back you would know. The tires with the least grip will try to get in front of the tires with the best grip...

Sure did. As hard as it would go. On parking lots I did lots of try (and error ;-)) things. On gravel and on snow as well as on dry tarmac.

I never had the problem that on my front driven A6 the rear broke out.

But I often had the problem that the car would understeer.

So, what are you guys doing differently?

Maybe I change tires too early to see that. Mine go when they are down to 2 mm for summer and less then 3 to 4 on winter tires.

Maybe I'm also OT as this is a quattro thread.

Regards

Wolfgang

If you are able to brake in a completely straight line, on a smooth surface, with absolutely constant coefficient of friction, then the rear tires will probably stay in line behind the front. Deviations from this ideal condition will require some quick reaction on the steering to keep the car straight.

However, if you hit a patch on the road with appreciably different traction, or if the right wheels encounter a different situation thasn the left, even fast steering reaction may not be enough to prevent the rear from coming around. Or if you are turning and still have to slow down (bad planning; unexpected obstacle, etc.)

A slight bit of understeer is not bad -- you just have to approach your corners a bit differently than if you had oversteer. A lot of understeer is not good -- neither is a lot of oversteer.

While a "expert driver" might get away with an oversteering car, the presciption to put the better tires on the rear is proper for "the average driver" and certainly safest for those with no clue at all. :-)

Jay Somerset schrieb:

This is entirely true for a non ABS car. But wrong for an Audi (or any other car wit ABS). BTDT myself more then once. We trained that on a 3 day handling/track training class and with the ABS on a full power brake with the left side on perfect race tarmac and the right side on deliberately slippery surface (a special surface which gets slippery like ice when wettened) it only required the slightest bit of countersteer, and I mean just a bit, to keep a straight line. All cars without ABS went off the track unless the would open the brakes, re-align and hit the brakes hard again.

Yep. Agreed.

Hmmm.

Regards

Wolfgang

I have to agree with Wolfgang. The braking system is biased towards the front wheels. They do most of the stopping. Plus, there is no way the rear end is going to come around regardless of the tire wear unless the rear locks up first which isn't going to happen on any car I've ever driven.

I've driven school cars with "bologna skins" on both the front and the rear with fwd cars. We called them bologna skins because they were nearly bald. But, they gave more of a foot print on the track and were better performers than *new* tires. Of course rain is another matter when tire treads are involved. I wouldn't want to drive a slick tire (bologna skin) in the rain, especially on the front.

I've owned Quattros for more than 20 years and the tires always wear the same. I rotate on a regular basis (every 10k miles), so the tires wear evenly. In fact, I've never seen a Quattro with tires that weren't worn evenly.

Well maintained (rotation and inflation) tires are essential to good safety and performance on any car, yet it is often the most overlooked item on the car. I see even cop cars with underinflated tires just begging to come off the wheel in an emergency high speed maneuver. Dave

"Wolfgang Pawlinetz" schreef in bericht news: snipped-for-privacy@4ax.com...

I believe it was when you're breaking into a slippery corner, it's for the average driver *easier* to escape from an understear (rear-tyres ok) then from an oversteer-situation (rear-tyres too 'slick').

The way the car goes with the least grip on the front will go in a straight line, when the least grip is on the back, the car will spin.

-- Dan

Understeer is corrected easily by releasing the throttel. Oversteer is difficult to cope with and needs a lot of space to correct. So in corners you prefer understeer and put the worn tires in front -it's always better not to use worn tires.

Ronald

Don't the tyre manufacturers themselves recommend that the tyres with most tread go on the rear - to protect themselves from liability?

-- Doug Ramage

I agree that ABS does make the problem largely go away, at least with braking, but on cornering the traction system is not as efficient in counteracting differential front/rear grip. if there is a marked difference in tread depth, I would put the better tires on the rear, even with AWD.