[mann]

I have an E91 (wagon) and just put on OEM 19" 220 wheels on and the DTC light will go off when accelerating. I also will feel the traction control kick on sometimes.
I am running a staggered set-up:
235/35/19 (8.5x19) - Front
265/30/19 (9.5x19) - Rear

Should I have run 225/30 up front and 255/35 in rear instead???

It seems that everything I have read and told I should have been fine?.....

Any guidance would be much appreciated as I am about to give up on the 19's and find some 18's instead.

[thegrinchboy]

Not sure who told you that your tire combination work but, with xDrive/all wheel drive, the rule of thumb is to keep the front and back within 1% of each other. The difference in diameter of your tires is as calculated at 6.661%. Thus your DTC is going crazy. Check it out yourself with the calculator... http://www.e90post.com/forums/forumdisplay.php?f=12

I wouldn't drive the car with this setup.

[danniexi]

Originally Posted by mann

235/30/19 - Front
265/35/19 - Rear

The tires you should be running are:

235/35/19
265/30/19

Unless that is what you meant.

[mann]

I did stopped driving right after the test drive and put back the stock wheels.

Should I be looking at the "difference in diameter" OR the "Percent difference"?

...and how are many other xi e9x's running this set-up?

[thegrinchboy]

Focus on the % difference. It should 1% or less.

I don't think you will find anyone running on your setup because it's way out of recommended spec.

[mike5809]

Originally Posted by danniexi

The tires you should be running are:

235/35/19
265/30/19

Unless that is what you meant.

Unless he changed it, that is what he said he put on

[danniexi]

Originally Posted by mike5809

Unless he changed it, that is what he said he put on

OP edited his original post; I assume it was a typo.

[mike5809]

Ah OK Figured that was the case. Interesting then that he is saying he has issues with 235/35 & 265/30

OP: What tires are they?

[b-man]

235/35 265/30 should be fine. I'm running 235/35 275/30 on 220

[mann]

Sorry for the late reply...

My original post was a typo on my tire size.
I have Goodyear F1's in front and Continental Sport Contact in the back.

The rear wheels I believe stuck out to much. When I would pull into any drive way I would rub somewhere.....not sure if it was in the front or back? It also looked like even if I would have rolled the rear fender the rear wheels still looked like it was sticking out to much.

I only took one picture of the car before putting original wheels back on...attached is the pic with them one....I hope I can figure this out or I am selling them and finding some 18's.

[zipstic]

Originally Posted by mann

Sorry for the late reply...

My original post was a typo on my tire size.
I have Goodyear F1's in front and Continental Sport Contact in the back.

The rear wheels I believe stuck out to much. When I would pull into any drive way I would rub somewhere.....not sure if it was in the front or back? It also looked like even if I would have rolled the rear fender the rear wheels still looked like it was sticking out to much.

I only took one picture of the car before putting original wheels back on...attached is the pic with them one....I hope I can figure this out or I am selling them and finding some 18's.

Do you know what the rolling diameters are for your tires? Brands will have different rolling diameters even though they state they are the same size. For example, the Hankook V12 evo12 in 265/30/19 has a 797 RPM whereas the conti DW has a 821 RPM. Obviously this is a huge difference. Also, are all 4 tires new? Or are they worn differently?

[mann]

No, I did not look at the tires Brand for specific tire rolling diameter. I just referenced the wheel offset calculator. Both sets of tires are about 95% new...

How would I translate RPM to Percent Difference (to be within 1%)?

[zipstic]

The RPM for the 235/35/19 Goodyear's is either 820 or 821 depending on which model you have. Since the latest Conti Sport Contacts models aren't made in 265/30/19 I'm not sure what the RPM is. You may have to do some digging.

Take the 820 (or 821) and divide by the Conti's RPM. It should be within 1%.

[Andrewe92]

1% rolling diameter difference between front and rear tires is the most you can get away with xdrive. i do believe it is because of the transfer case