My 20" a6 wheel is a 35 series tire. The 19" a6 wheel is a 40 series.

1 inch difference is a 05 profile difference in tire size to keep the ride height the same.

So if a 20" q7 is a 45 series tire, i don't see how using a 21" wheel and a 40 series tire is going to mess things up.

Every other car in Audis line up does the same thing. An 18 inch a4 wheels is 40 series, and 19 goes to 35 series.

I'm not sure why Audi went down 2 profile sizes 45 to 35 on the q7 wheel and tire for a 1 inch difference in rim.

 

What tyre pressures should you be running with Michelin tyres 21 inch?

 

What tyre pressures shoud you be using with 21 inch michelins?

 

44 front, 49 rear is what was recommended

 

That's correct under full load. It's 36/35 psi under normal load according to the manual.

 

I have not had a chance to take any pics but I do have about 1500 miles on the Vredestiens now and will say that they are a great tire! Very quiet do to the asymmetrical but NON directional design. I actually thought they sent me four left side tires because they look like they should be directional based on the tread pattern. But this is by design...the left hand tire tread spins in one direction and the other spins the opposite which creates less chance of any harmonic road noise. There is also no tram lining on hiway grooves since there is only one groove that runs parallel to the road. My Contis would rip the wheel out of your hand at any groove in the road.

These also grip the road very well! This is one of the best all around tires I have used on and SUV (and I have tries most of them).

Add in the fact that this is the lowest price tire in the 295-35-21 spec and I am more than thrilled!

Get them, you will not be dissapointed

 

Update on my use of 295/40 21.
Have decided to go back to 295/35 21 for three reasons.
1. I like to use spacers and this not possible on front with 295/40 21 as spacers cause the increased diameter wheel to rub on arches on near full lock.
2. I have to say that steering feels sharper with 295/35 21 maybe because of less weight( or maybe my 295/35 21 Pirellis are better tyre than 295/40 continentals.
3. Ride now dosent feel that different now I've got 295/35 back on.

Hope someone finds the above useful

 

G'day Audi fans -

Recently upgraded to the 2011 S-Line TDi and absolutely loving it - aside from the noisy, super-soft compound and fast-wearing Dunlop Sport Maxx. So when they wore down I went to replace them and found the choice of OEM tire (295/35 r21) was staggeringly narrow. Also found it really hard to find information for this difficult size so wanted to post my experience up.
I ended up picking Continentals, but the America's Tire rep (who I've always had great experiences with) told me they weren't sufficiently load rated for the car, and suggested bumping up one (profile) size.
So here you can see the 'before' - 295/35r21 Dunlops, and 'after' - Continental 295/40R21XL 111W MBZ ContiCrossContact.
It's amazing what a difference it makes on a lot of levels. Visually I like the fatter look, and the way they better fill the arches (although, yes, in the after picture the car is on 'DYNAMIC' and originally it was in 'COMFORT'.) The ride is incredibly improved. Infinitely more quiet, 30% more comfortable without losing any handling (although I haven't done much more than city driving yet). Even my passengers, who'd accompanied me to the tire store, remarked on the immediate difference they could feel as we left.
But here's the catch: on the lowest -DYNAMIC - adaptive air suspension setting, the FRONT TIRES RUBBED THE FRONT EDGES OF THE ARCHES ON FULL LOCK TURN. Of course I discovered this as soon as I began to reverse out of the tire place, and immediately flagged it with the manager. In the end I decided to stick with it because a) I rarely use Dynamic mode, and if I do, it's for higher-speed driving - not car park maneuvering, and b) I wanted to see if the ride was sufficiently improved. As outlined above, it definitely was.
Sure, the speedo and odo will be out a bit (the latter 'in my favor') but that doesn't worry me too much.
So there you have it, hope that helps other 21"-rollin' Q7 drivers who are wondering about tire options. Love to hear other people's experiences.

Before and after: 2011 Q7 S-Line on 295/35r21 OEMs, and 295/40r21 Continentals.

 

using vcds / vagcom adjust the tire circumference so the speedo and nav adapt properly and read accurately.

 

Wait...one of you said moving up to the 40 series tire would cause your odometer to be higher than actual miles, and the other says it will be in your favor slightly...which is it?

edit << nevermind on the above - read this backwards "100 odometer miles would really be 108.43." >>

And has anyone confirmed you can adjust with VAGCOM? I really want to bump up to the 40 series tire and get some all season tires instead of just dumping the 21" rims and getting 20's or smaller, but need to confirm there won't be issues besides rubbing at full turn/stop.