MP4.2+6.0

All good, but I would not assume the original size actually reads correctly to start with. In fact, a better assumption is it does not--and is almost invariably a bit optimistic. Audi, or whatever the make and model. The reason is a manufacturer gets fined for selling a non-compliant vehicle if the car is equipped with speedo that reads even slightly too low, but not if it reads marginally high. Thus, they err that way. But yes, it then means the 255 math relative to actual is marginally yet more off.

Best way to check these days is a simple GPS app on a phone. Just drive down road at whatever indicated speed you want and compare it to phone display. For me, the 275/40-20's in either Conti DW (summers) or DWS-06 (A/S's) are dead nuts correct. The very slightly smaller diameter 275/35-21's mine came with were...slightly optimistic.

LexusLSguy

My next set is going to be the Pirelli Cinturato P7's. I have new Continetals from the CPO right now and they are OK. The P7's are rated as one of the best all season out there by Consumer Reports. On the 19" wheel they have a 700 tread life rating but it goes down to 500 on the 20". Anyway, if you guys have not researched this tire I suggest you do. I am also an avid Michelin fan and my old MXV4's were the best tires I have ever owned. The Premier A/S are fantastic tires as well but not offered in my size. Many LS owners use them on the 430 and 460 and rave about the handing / quietness. I have not personally owned a set yet but I do trust the massive threads about them on the Lexus forums. Obviously, if you live in a warm climate year round you may not want an all season vs a summer tire but here in the northeast unless you run two sets they are a must. Summer tires really suck in the snow / ice.

Baloo588

I am getting my 255/40R20 Michelin Pilot Sport AS plus Nspec mounted on tuesday and will get back to you guys how the ride feels in terms of smoothness, absorbing bumps etc.

As for the P7, the newer version is the P7 plus which we have on a Mercedes S550 and those are really smooth and quiet vs the older P7. Tirerack forums show many people more happier with the P7 plus. I just dont know why they aren't making bigger and wider size P7 plus for the A8...

Baloo588

If you look at these pics of the Michelin Pilot Sport AS plus n-spec you can see there is really good thread depth and the pattern looks very smooth and nice for the A8. The porsche panamera drivers are commenting on how smooth and quiet and great traction these tires are over all with 40k plus mileage on some of the sets. This is good because thats what I want and especially with porsche lvl of tolerance and expectations, Michelin designed this tire with that in mind. Also its 101V rated which will be smoother than the 101Y I currently have on the AS3. Also the sidewall is thick enough. I had a D3 2006 Audi A8L with 255/40R19 and the ride was very smooth at this thickness and never had issue with bent rims etc in 180k miles on that car.

Baloo588

For those who want another option such as the 275/40R20 then Michelin released a new version AS3 N-spec.

https://www.tirerack.com/tires/tires...FQMIaQodrvkMeg

LexusLSguy

That is interesting baloo that they don't offer the plus once you go to a 20" wheel. I'm sure the Michelins will be nice tires. About 90% are. I don't think you will get 40k miles out of them but I could be wrong. Looking forward to your review.

GR8-LIFE

I've had bad luck with tires. I complained about the Pirellis making noise at 14K miles. Then I went with Conti Sport contact 3's to replace them and the conties wore unevenely (I rotate every 5K miles._ The right rear hit the wear bar at 10K miles! I couldnt believe it. The car began to drive like crap. Continental wouldnt do ****. So no more Contis

Then I tried the Firestone INdy 500's (270-20) They were ok at first but at 1K mile I am hearing realy bad variable pitch noise between 35-50 mph. You could hear it on smooth roads. The tires didnt seem to be balanced well either. Tires Plus balanced a 2nd time. Not that much better. We cross rotated and the noise pitch changed somewhat but I still hear it. The noise will only get worse if its a tire

Suddenly the OEM pirellis arent looking that bad so i am trying to negotiate with Tires plus in getting back to the Pirellis. What an ordeal!

I have concluded that the tires industry is a very ugly one especially with performance tires. I have even had my dealer say he is reluctant to align cars that change the size although I wouldnt consider 265 to 270 a change. Thats not even a 1-up!

LexusLSguy

Are you getting an alignment done with each new set of tires? Running through tires in 10k miles means something is wrong somewhere.

GR8-LIFE

It goes on the rack and if needs an aligment it gets it. Have never had the tire woes that I have had with mY A8 and I have had over 30 cars.

Hindsight is 20-20 but Never should have changed out the Pirellis even though I am not a fan of them on a big luxury car. But 14K miles (which is about 2 years for me) isnt bad on that kind of tire when listening to others getting even less miles with other tires.

I figured I would get much more tred from the Conti sport Contact 3's. Nope. And Like I said, Continental didnt do squat about it. Do some reviews. You will see others getting poor tred life as well

cleex024

you also have to remember that your mpg goes down because your car now reads 2-3 mph slower. so when driving 60 your car will actually be going 62-63 mph. when calculating mpg you have to put in that deviation now...bascially you are getting around 2 mpg more than what you calculated.

you arent really having bad luck...those tires you chose are not that good of tires if you go read reviews on tirerack...i would only go with tires that are at least 4.5 star rated on tirerack unless you are going with something more specialized like track only type of tires.

try the conti extreme contact dws 06s that everyone is recommending here or anything else they are recommending. those are all highly recommended on tirerack too.