AaronL

...toe adjustment: I have heard both suggestions for my car, but I wonder if I could get a more definite answer. The symptom is that the front left tire is nearer to its low thread marker plus is almost completely worn out at the outer edge only. Right front tire has normal wear and not as worn out as the left one.

Any ideas? Is this an alignment or left front toe issue?

OOOOya

Just measure across groove to groove on the front & rear side of the front tires - as high up as you can without the tape measure contacting the underside of the car (which won't be very high up). Anything more than 1/16" should be corrected soon.

Last fall I had 1 tire worn completely bald on the inside shoulder due to 5/32" toe in.

AaronL

Groove to groove, w/o contacting the underside of the car? Do you have any photos on how?

gondar

the measurement suggested is of non-parallelism, how much the inward the fronts of the tires are, toward each, other relative to the rears.

a badly worn outer tire edge sounds like too much positive camber on that side, but on these cars to adjust the camber you move the whole subframe relative to the body and one side affects the other. you have to split the values. Audi cheaped out on that. OF course you could have combined toe and camber issues.

you can often detect bad toe wear by feel, running your fingers sideways across the tread (pervert) it feels directional, like velvet, more one way than the other. it can be quite noticable.

AaronL

How much is a complete toe/camber adjustment on A8s?

AaronL

Alignment = Done at an Audi stealer or any respectable shop would do, right?

OOOOya

No pictures though...visualize...

Preferably car is sitting on a level surface with the wheels pointed straight ahead.

Feed the tape measure under the car from one side - start with it either behind or in front of the front tires. Have one person hold the "dumb end" of the tape measure in one of the tread grooves. Doesn't matter which one, as long as they use the same groove on the front and back side. You'll want the tape measure up as close to the under carriage without touching it (it's spanning the width of the car at this point). Make sure it's not twisted or sagging. Read the "smart end" of tape measure at any convenient point - I usually pick a tread groove that lines up nicely with one of the 1/16" marks on the tape. WRITE THE NUMBER DOWN because you'll surely forget what you said when you move to the front/back side. I do...

Make the same measurement on the opposite side (front/back) of the tire. Both people should use their same respective tread groove or you'll be way off.