Koru_Kinshi

I've been doing some research on widening tires, and it seems that 20 wider is the max anyone recommends.

I'd like to get some wider tires under the wheels when it's time to replace, but I want to have a good balance of power management and handling. I was thinking of either going 10 wider all around, or maybe leaving the front stock and going 10 wider on the back. I have no intention of getting different rims. What do you guys think? I know on the SL's they have a 30 width difference between the front and the back, the V12 going 255/285.

Toadster

i'm putting Hancook Ventus V12 245/40-18 in front and 275/35-18 out back

not sure if the V12 255 will fit up front

I was searching for pricing, and was shocked to see that Amazon sells Michelin tires now too!

cij911

You have to size the tire to the rim. If you put too big a tire on a rim, your car will handle worse as the tire will roll over the rim.

If you are interested in performance, you will want to get as wide and as light a rim as possible. From the research I have done, it appears you should do a 18x~9" F and 18x~10.5" R. A lot of folks put 19s or 20s on their cars and don't even know what the rims weigh - just for looks I guess. The net is the car handles worse or rides like crap - they will tell you it rides fine.

Additionally, as you increase the rim diameter, you have to decrease the tire profile, which in my humble opinion is bad for our cars as the sidewall becomes too small (on a 20") and will ruin ride quality (for a luxury street car).

AgSilver

masonh66

well said.i still can't figure why so many 20" wheels for these cars?i wouldn't put 20's on my E63 if you paid me.

i could probably get used to the ride,but i want all the handling i can get out of my car,so i put some sub-20lb 18" wheels on it with some sub-25lb tires.

pearlpower

It's a matter of balance. The E55 has extreme understeer from the factory which explains why it is not balanced clipping the apex in a corner.

Compound this with folks eager to run wider rear tires to tame wheel spin without understanding handling, now you have a car that has even more understeer making the car handle like a Big Wheel.

Google oversteer/understeer on proper tire sizing and pressures to assist.

http://en.wikipedia.org/wiki/Understeer_and_oversteer

also search this forum as it has been discussed in the past a few times.

Toadster

all depends on the application though... drag guys will put huge tires out back and skinnies up front - not a track car then

would be interesting to see some track times with the rear wheels all around

pearlpower

He is referring to HANDLING, not track.

Koru_Kinshi

I *did* do a search, and all I found 90% of the time was argument...which seems to happen quite often on this forum. I just want to know people's personal experiences and what not, heh. On my C32, I went 10 wider all around which seemed to do nicely, hence why I'm curious if the same theory will work here as well. I really don't feel like getting different rims and junk. I like the stock look as it is.

cij911

I know you understand what I am about to say, so this is not geared towards you...

There is a lot more than tire width and pressure that determines how a car handles. IMHO, the e55 is a nice luxury sports tourer, that in many cases can "eat" many a sports car. Most OEMs intentionally design understeer into the factory alignment and suspension settings, but these can be tweaked for advanced drivers that want oversteer.

I drive my car with ESP off and have no problem getting the car to rotate in a turn. If I were to take the e55 to a road circuit, I would change the front geometry a bit and probably try to fit a 9.5" rim, but for the street I don't feel that will make any difference for 99% of the drivers.

Now the rear is another story IMHO. With 500+ ft lbs of torque, the factory rubber is challenged to put the power to the ground. I would LOVE to put 12" or 13" rubber in the back (like a 911) and be able to use the power more and traction control less....Unfortunately we are limited to ~11" in the rear...

Just my $0.02...

Koru_Kinshi

So long story short the only reason to change tire width is to hold power down to the ground better. Best to leave it stock otherwise then if I don't want to change rims, yes?

cij911

If you want cliff notes, yes....

A wider tire will give you better lateral acceleration as well (assuming you use the same tire compound)....

You can also buy lighter rims to improve acceleration and braking, but my guess is you won't push your car hard enough to know the difference.

So net / net, keep your stock rims and stock tire dimensions....

AgSilver

Lightweight rotors, KMAC adjustable bushings, toe-links and 18" Toyo Proxes or equivalent and lowering the car about 1" will result in a remarkable improvement in the handling qualities.