2008 A4 --Tire Load Question---Doc or Others

**A4B07** · 08-15-2008 03:43 PM

2008 A4 Avant 2.0 6MT

Was putting order through today but ran into this issue:

The factory 17 x 7.5 rims have tires with Load Cap of 94H or 1477lbs (235/45/17).

I am looking to switch to 18"x 8.5-235/40/18.

The tires I am looking at tirerack are Yokohama Advan S4.
Tirerack pulls them up as OK application, but they are 91H / 1356lbs.

Max load of vehicle(vehicle weight + max cargo load) divided on the 4 tires (even taking uuneven fore/aft weight distribution into account) puts the max load at 1356 or 91H per tire.

-What is the minimum load that is OK?
-Is Audi putting 94 because of extra rim protection?

-Is 91 OK as per Tirerack recommendation? Or should I stick to 94?

--Anyone done 91?

Any insight would be appreciated.

Any ideas?

Thanks.

**Doc@tirerack** · 08-18-2008 09:57 AM

We require the 235/40R18 to be a 93 load index or higher. I don't have the axle ratings in from of me to help tell why, but if the 91 load carries enough, it most likely so close that if you did not check your PSI everyday (and fell below 36) you'd been in trouble.

**A4B07** · 08-19-2008 02:20 PM

I am getting conflicting info on this even from you guys at Tirerack.

The problem in complicated with Audi now NOT putting a GAWR Axle load sticker on door and replacing it with just a tire size and Max Load sticker.

-As stated Calculating the weight of car (3670lbs), with correct Front / Rear Weight distribution and adding the Max Allowed Load for Car (from sticker in Door), the front Axle load comes in at 1350 (rear is lower-the car being front heavy)- which is 91 load (at 36psi as you mentioned)

----- But let me ask this a different way:

1)The OEM tires on the car are the Conti ProContacts 235/45/17 - 94 XL , with a load of 1477. But from what I understand this is calculated at 41 psi (since XL).

2) Audi tells you to run them at 35psi which should make them around load 1356 at this pressure? Am I correct?

So what is the difference between the 94XL at 35 psi (1356 load) versus 91SL at 36psi (1356 load)????

1356 is 1356- Isn't it?
Am I overlooking something?

Am I getting better Rim protection because of the Reinforced XL's? Is this the difference?

What gives?

Thanks.

**Doc@tirerack** · 08-19-2008 02:59 PM

I found a picture of a sticker (2007 A4 Avant 2.0) that puts the gross Vehicle Weight Rating at 5,400 lbs, and the (heavier) front axle rated at 2,579 lbs. After looking at that, I can only assume Audi requires XL more as protection for the wheel (and to minimize the chance of bubbles on the sidewall.)

**A4B07** · 08-19-2008 03:53 PM

And so I assume the 91Y SL Yokohama S4's (235/40/18) with 1356lbs will NOT be a problem then.

If this is so Please Confirm and I will put order through.

That would be good news since the two tires of choice (Yoko's and Michelin PS AS2) are both same 91 rating-

Leaning towards Yoko's because of Michelin's noise issues as they go over 10-15k and slight edge for light snow to Yoko's from those whio have used the 2.

Unless you want to talk me out of one over other.

Thanks Again.

**Doc@tirerack** · 08-19-2008 04:08 PM

The main thing will be to make sure you are at (or above) 36 PSI all the time to prevent blowouts or premature wear.

**FLAudiMotion** · 11-07-2008 10:30 PM

yeah, so i am in the same situation. and i dont think this was really answered in this thread yet. I have 94H and i am leaning towards buying tires rated at 91Y. Is the general consensus that 91Y will be okay on a B7 A4 Q?