Jordan12

Hey guys,

with the winter just around the corner in the northeast, I swapped the summer wheels & tires on my e55 with a set of winters I had from my old S4 (245/45/18, Blizzak WS70s, mounted on 18x8 rims). The bolt pattern and hub diameter match perfectly, the offset is not ideal in the front, but with a set of spacers they seem to fit fine, no rubbing.

Here is my issue: the car feels a bit "twitchy" around 70 mph. Not sure what is causing it, the lugs are torqued properly, do not seem to loosen up with driving, nothing is rubbing (inside, outside, brake calipers, etc....). I may also be imagining this, but I do feel a slight oscillation coming from the rear.

Also the traction control warning light comes on way too much, even when braking (never seen this before) and when going over uneven roads, etc... I have only seen it flicker during hard acceleration before.

Anyone else had any experience like this? I forgot to mention that in the rear I use no spacers and as such my wheels are more than 20 mm closer to the mid-line of the car (effectively decreasing the width in the rear by 40+ mm.

Thanks,
--Jordan

Hotsauce55

Is the distance between your front tires greater than your rear tires? Like a reverse stagger setup?

uraberg

the circumference of the stock tires is about 80 inches. 245/45-18 is almost 84. I'm guessing this screws with the car's expected wheel rotation at a given speed.

Jordan12

Yes the rear wheels are currently narrower by [maybe] 20 mm. Do you think this would be a problem? I ordered a pair of 15mm spacers for my rear wheels anyways, should bring the rears out farther than the fronts.

Jordan12

My apologies, I mis-typed the size of my winter tires. They are 245/40-18, which means the circumference is 80.8". Rear stock tires (265/35-18) have circumference of 79.5". Do you think this may cause a problem? it is less than 2% difference?

Hotsauce55

Load transferring, wider track and less load gets transferred vs a shorter track. I would think then the rear effectively gets more load transferred to it making it feel "twitchy". May not be your problem but seems to make sense to me. Consider putting the proper rims on the car.

Jordan12

Do you not think spacing these out in the back would work? Tirerack's recommended package for my car is 18x8 and their recommended tire size is 245/40-18. The only difference is that they use different offset (35mm in the back vs. 45mm which us what I have). This is why I think using 10mm spacers should do the trick. I can even go to 15mm in the back to get some more staggering. Or am I missing something?

Hotsauce55

Might work, the staggering may not even be a problem... give it a go

Nanook

Are the tires directional and if so properly oriented ?

Jordan12

Yes, they are directional and are properly oriented.

Does anyone have any thoughts on the traction control light coming on during braking? This one really puzzles me.

Thanks,
--Jordan

Nanook

Sounds like a diameter variation

Jordan12

Hmm.... So the e55 normally runs on mis-matched wheels, with diameter difference between fronts (245/40-18) and rears (265/35-18) of approximately 2% (25.7" vs 25.3"). My current setup, with all 4 winter tires at 245/40-18 probably has a variation on less than 1/8 inch, entirely due to wear (front pair is a bit more worn down, sub-1/16 difference). 2/16 out of 25.6 is just under 1/2%, so a 4-fold less diameter variation than stock.

Or maybe the ABS and traction system expect a mismatch and need to be reprogrammed? But for a RWD car, this would be truly excessive. Of course if any car out there would have such a "feature" it would likely be an AMG Merc

Nanook

Nah..can't be the issue then...something else is amiss

tscales

I ran single size Blizzaks on mine for a long time. That said, I'm not sure I ever got it to 70mph in the winter.

Honestly, I found the car almost unusable in snow, even with snow tires. I tended to park it in favor of other vehicles (primarily a 996TT).

Now I live in Florida, so....

2000UZJ

What are the aspect ratio's of the tires? I had 245/35 and 275/40 on mine for the past week and kept getting ABS/ESP lights and limp mode on the highway.

p.s. i didn't have a choice. had a blow out and new rims on the way so I picked up what was free

tscales

245/40R18 all around. It was a tire/wheel package from Tirerack.

The stock staggered tires are only 6/10ths difference in diameter.