nawlinstornado

I'm looking to modify my stock setup from:
235/40-18x8 ET 45MM (front)
255/35-18x8.5 ET 49MM (rear)

to:
255/35-19x8.5 ET XX (front)
285/30-19x9.5 ET XX (rear)

I've noticed everyone that has 35mm offset front and rear seems happy, but I'm nervous about shifting the center axis that far outward. I like the 45mm offset fitment better, but am concerned about rubbing. Performance is my biggest concern, not appearance.

Help?

nawlinstornado

Here are the fitment numbers I've been looking at:

Front with 35MM offset:
http://www.willtheyfit.com/index.php...&Submit=Submit

Front with 45mm offset:
http://www.willtheyfit.com/index.php...&Submit=Submit

Rear with 35mm offset:
http://www.willtheyfit.com/index.php...&Submit=Submit

Rear with 45mm offset:
http://www.willtheyfit.com/index.php...&Submit=Submit

threeMBs

Rear 9.5" wide et35 wheel with 285 tire will stick out by over 1/3" (need et42-43, but will it have enough inner clearance will depend on tire's manufacturer as some are wider than others). 275 tire on 9.5" et40 (+/- 2mm) is a sure fit.

Front 8.5" wide et35 wheel with 245 tire is perfect, while 255 will require et38-40 offset.

IMHO, wider than stock rear tires are mandatory for C207/A207 E550s. So while 245/275 will have zero fitment issues and will improve traction over stock, 255/285 may present some headaches if offsets are not spot on and/or tire is too square.

nawlinstornado

ThreeMBs,
What width/offset do you have on your 20" wheels?

threeMBs

8.5" et30 front and 9.5" et37 rear, but with 235/35-20 front and 265/30-20 (1" taller than stock) rear tires. IMHO, to handle traction issues (I assume that's why you're looking for widest possible tires) you can go wider tires or taller diameters. Both methods work.

nawlinstornado

Traction is the problem, both off the line and cornering. While the car exhibits understeer in normal driving, performance driving exposes a lot of oversteer. The eventual availability of an LSD (I hope) will help but I still think the extra rubber is a necessity.

Based on the "will they fit" calculator, an ET45 on the front results in increases of 6.4mm, 6.4mm, and 8mm to poke, inset, and radius, respectively. This looks really good to me as the poke is less than 245 on ET 35 and I'm sure the 1/4" inset and 1/3" radius won't be a problem.

ET45 rear, though, results in increases of 16.7mm, 8.7mm, and 9mm to the poke, inset, and radius. The poke is less than a 275 on ET35, and I don't think the radius will be an issue. I'm concerned the inset may be getting a little close to the suspension, though.

threeMBs

FYI: it is considered safe to move wheels' center line by upto 10mm. The widths and offsets I provided in my first post are within this guidline and is close to what I use on my 19" wheels. On my 20" wheels, I do use even more aggressive offsets, hence narrower tires.

nawlinstornado

I'm at the point where, if I can't find someone that has a full set of measurements or experience with ET45 application on this car, I'm just going to buy the 45mm offset and and some spacers. I found a place online that sells 5mm hub centric spacers for $40/pair.

threeMBs

1. What's the point of buying et45 wheels then use 5mm spacers for et40? Just buy et40 wheels, unless wheels you like are not available in around et40.

2. Specifically to 5mm spacers. You can not use them on C207's hubs. Hubs are only 6-7mm. After 5mm spacers - only 1-2mm left to seat wheels on. Not enough. Your wheels' weight will be supported by bolts instead of hub. Not a good idea.

nawlinstornado

The wheels I've been looking at are only available in 35 and 45. I don't plan to use the spacers unless there is a fitment issue.

I'm not concerned. Vehicle weight is not supported by the hubs or bolts, regardless of application, but by static surface friction generated by bolt tension.

nawlinstornado

Update:

I took a chance and went with my gut. Bought the 19x8.5 front, 19x9.5 rear with ET 45 on both. Loaded them with 255/35 and 285/30 Conti ExtremeContact DWS and VOILA! It worked! Although I was a little shocked at how wrong I was about the rear fitment. I thought there would be plenty of room on the front and very little on the rear. Once mounted, I had about 7mm space left on the front but plenty on the rear.

Anyway, no issues. I've driven the car lock-to-lock in a parking lot, driven over speed bumps, etc. and there is no rubbing whatsoever. I still haven't driven on them enough to feel confident testing the limits of adhesion, but the ride quality is unchanged and the handling is every bit as responsive as stock.

I'll post up some pics as soon as I have a chance.

nawlinstornado

****Update****

After some "spirited" driving, I ended up putting 5mm spacers on the front. Although the fitment was fine for city driving, the inside corners of the front tires would rub the lower assembly spring plate when under heavy load (hard braking or cornering). Not enough to damage the tire but it made a lot of noise and would cause some minor oversteer near the limit. The 5mm spacer has provided just enough room for the tire.

I'm also very impressed by the Conti ExtremeContact DWS tires. Night-and-day difference from the Pirelli PZero M&S from the factory. The difference in dry weather traction is more significant than could be expected from the extra 30mm/20mm (rear/front), and the wet weather traction is incredible. I don't see the blinking yellow light nearly as often.

I was at the dealership this weekend and noticed the 2013 went back to the Michelin Primacy MXM4 - not much of a shock. The Pirellis just aren't that impressive.

Anyway, as promised, here are some pics of the final installation. The front and rear are almost perfectly flush with the body, and the stock alightment settings still allow the tire to recess into the wheel-well without rubbing anywhere.

2010_E550

Good to hear that it worked out for you. I plan on running 19x9 et 35 front, 19x10.5 et 40 rear.

The factory Pirelli's are pure garbage. We all know that first hand.

I just put Vredestein Ultrac Sessanta in 235/40/18 and 255/35/18 on two weeks ago at a cold tire pressure of 28 psi front, 34 psi rear.

An amazing tire! Quiet, comfortable, and once they warm up the grip is surprising. All four shipped for ~ $850. Cant beat that.

If you haven't tried these tires yet I highly recommend them.

nawlinstornado

I'm really happy with the Continentals. Quieter, better traction, responsive, etc. I've been running the factory-recommended 36psi all the way around and have been very impressed. The wheels, on the otherhand...... See my other threads if you're interested in them.