atgd

Have you thought of the new 2013 SL or E63 wheels (the 19" twin five spoke ones). Good match for your setup: 255 fronts and 285 backs at 19". Do not know whether the offset fitment will work, though. The mechanic I spoke at MB Boston, seems to think that the E63s should fit.

Worth looking into it, albeit not cheap.

Anyway love your car. Just got mine last week: '10 E550 Coupe, Palladium Silver/black interior w P2 + Appearance pkg.

nawlinstornado

I'm sticking with what I know works. The ExtremeContact DWS fit (per manufacturer specs) on those size wheels and I'm really happy with the tires. I'd rather not tempt fate by making any changes.

Looks likely that I'll be purchasing a set of BBS CH-R in silver. They have the right size, bolt pattern, and offset (40 front, 45 rear) so that I can get rid of the spacers.

nawlinstornado

Good suggestion, but I just checked the offsets on those wheels and they are off. On the E63, I'd need spacers on the rear. For the SL wheels, the front would stick out too far.

nawlinstornado

Alrighty, then. Just ordered the BBS CH-R in Silver, 19x8.5 ET40 and 19x9.5 ET45. I hope they don't take long to come in. The current wheels are getting worse and I don't really drive my car any more. I could put the factory wheels back on but I'm just too lazy for that!

Dueclaws

Congrats! Great choice.

nawlinstornado

Here's my last update on this thread:

I placed my order through the Vivid Racing website this morning as they had the best price I could find online. When I called later to find out if the wheels were actually in stock, I learned they did not have the rears and there would be a three-week wait. Since I can't really drive my car right now, this was unacceptable. My Edge is okay, but I miss my Benz!

Just out of curiosity, I decided to call Tire Rack. Their website didn't show they had the wheels in my size, but what's a few minutes on the phone, right? Turns out they had them in stock and on sale for the same price as Vivid. Plus, their shipping charges were cheaper (by $10) and they are throwing in the proper lug bolts (conical) for free.

I cancelled the Vivid order and bought them through Tire Rack. The salesman said they should arrive on Wednesday so I'm making an appointment to get them put on Friday morning. I am a little nervous as they are a bit "louder" than I was looking for, but I think they will look great. I'll post up pics as soon as they are installed.

Dueclaws

Sweet! Looking forward to your pics and good call contacting Tire Rack.
I must add that your 255/285 combo and offset work was great pioneering for the rest of us.
Thanks! What's the difference in speedo vs. actual speed?

nawlinstornado

Good question. Mathematically calculated, the speedometer should read 58.36 @ 60mph actual. However, I'm a little confused as there is a police radar speed sign that I've "confirmed" my speed against with both the old and new setup. No difference was observed.

I asked my MB service tech about calibrating the speedometer (before I actually installed the new tires) and he said there was no need to. It kind of begs the question: with all the tight integration, does the computer verify pulse readings aginst the GPS and adjust automatically? Or is my "observation" of the speedometer and sign a little off? I plan to ask the tech when I take my car in for its 10K service.

Dueclaws

Would be great if the computer is verifying against the GPS!
Have the larger tires alleviated most of the traction problems?
Thanks!

nawlinstornado

Alleviated? No. Improved? Yes! Cornering under power no longer delivers the oversteer I was experiencing - it's almost dead neutral with "spirited" accelerations, goes into slight understeer as you add a little more power, starts to drift straight with a hair more, and then goes into massive oversteer with the foot all the way down.

Straight line acceleration is still a problem, but I'm not squeaking my tires in 3rd gear anymore. The only real solution is to get a limited-slip diff, or 570mm rear tires, to get the full benefit of the rear tires.

Dueclaws

Unfortunate the transmission computer doesn't self-adjust for alternate rear axle ratios to allow fitment of a differential with LSD.

nawlinstornado

Agreed. I need to ping RennTech again about developing an LSD for the 550s. I offered them my car as a test mule, and they seemed interested back in May, but I haven't heard from them since.


Time to call and annoy them some more.

nawlinstornado

Just for fun, I looked up the specific tire dimensions for the Continentals and the Pirellis. The difference is less than the size theoretical measurements I gave before.

The Pirelli PZero Nero All-Season are spec'd at 825 revolutions per mile. The Continentals in my size are spec'd at 811. That works out to 58.98 mph indicated at 60 mph actual. I doubt my foot/eyes are good enough to work out 1 mph with a radar speed sign. Hell, tire pressure could make up for 1mph!

Dueclaws

I'm guessing the Michelin Pilot Sports (my fav) are too large, but haven't checked dimensions.

nawlinstornado

Pics of my new, new wheels are up. Check them out here: https://mbworld.org/forums/e-class-c...hopefully.html