KCviper

Can anyone comment on the speedo effects when going with the 275/35/18 and 245/40/18? I know the 265/35/18 are very close, but just interested in your opinions for "when it's time".......

ZephyrAMG

Where is the best place to change tires here in the US? Discount tire? Firestone? Goodyear? Dealership?

A place that wont throw your rims around when they change them...

c32kompressor

i had tire kingdom do mine. they were great and relativley inexpansive (cheaper than most places) dont go through the dealer, i have michellin a/s + and for two it costed me 495$, the same tires through my dealer would have run me around 600$ the dealer is a rip off!!

Bonk

To compare the effects on the speedometer/odometer, you have to calculate the % error that the new tires introduce in terms of differing diameters.

Calculate the tire's diameter as follows:

If the tire is www/ppRdd then the diameter in inches is (www*0.pp/12.7)+dd

For the stock tire size of 255/35R18, the diameter is (255*0.35/12.7)+18 = 25.03 inches.

Let's say you decide to go with 275/35R18s instead then the new tire's diameter is (275*0.35/12.7)+18 = 25.58 inches.

The new tire is 25.58-25.03 = 0.55 inches larger in diameter.

The overall speedometer/odometer error is therefore [difference/original diameter] ie. 0.55/25.03 ~= 2.2%

This means if your speedometer says you're going 100mph you're actually going 102.2mph. If your odometer says you've driven 10000 miles you've actually driven 10220 miles. This error obviously only applies while you have the new tires on.

Speedometers usually have anywhere from 0-5% error anyway so I wouldn't worry about the effects for this size tire.

You can also use the same formula when thinking of moving to 19"/20" wheels as well... your goal is to find a tire/wheel combo that will stay as close as possible to the stock diameter of 25.03".

baabootoo

My local Sears store had two machines; one specifically for larger wheels. It was only $13 a tire for mounting and balancing too.

LP560-4

Will somebody kindly tell me if I should be switching out just my rears or all four at once for the first tire swap. I have 7k miles.


Also if I were to change only the rears the first time, would it be about right to change the fronts together when I change the rears for the 2nd time (I assume after another 12-15k miles)?

c32kompressor

i changed just my rear i think it was fine. i dont see the need to get new fronts when you dont need them, if its not on the wear bar than there's no reason to

sflgator

+1. It's okay to run different rear tires than the front, but try to keep the tread pattern similar. My oem Pirelli P-Zero's on the front have 15k mi. on them and they're almost ready to be changed; got the Michelin A/S on the rear now.

LP560-4

Is tirerack the best place to buy tires?

KCviper

Thanks for the explaination! I just don't want the speedo, etc to be very far off....

LP560-4

Its usually only off by like 2-3 miles max.

LP560-4

Tirerack has PS2 for around 700 bucks for rear two tires. Is this a reasonable price? Should I save a couple hundred bucks and just go with the Bridgestones RE050A PP?

Even Money

I'm about to spring for some Hankook v12s, 245/40/18 and 275/35/18. My guy swears by 'em. 700 for 2 tires is ridiculous, especially when you burn through 'em in about 5K miles..

NickZag

I was looking into these also, they've had good reviews. If you wouldn't mind posting your opinion after you get some miles on them we would appreciate it!

baabootoo

Check Discount Tire also. Their prices are usually better than on the internet add. E-mail/call them direct for exactly what you want.

REDSRT

I recently installed the Hankooks Ventus V12 Evo's 265/35/18...Great tires so sar, sticky if not stickier than the Pirellis, especially in the twisties. Aggressive thread pattern, and the launches seemed to improve. Pretty cheap too, around $350 bux installed

REDSRT

https://mbworld.org/forums/c63-amg-w...s-v12-evo.html

Even Money

You think 275 will fit?

propain

Thanks for the info all!!

Now to choose the tires im going to use. I still have about 6K left on the front OEM's so im leaving those on for now.

What do you guys think about the VENTUS V12 EVO K110? How about the Dunlop Direzza Sport Z1 Star Spec? Sumitomo HTR Z III?

Im obvisouly looking for good grip and better tread life than the Pirelli's without spending more than $200ish a tire.

The Star specs I hear are the best but they cost $220 each. Im willing to go with them if they are as good as the reviews are saying.

Whatcha think?

LP560-4

Those are all extreme performance tires, right?


Are they loud and uncomfortable?

maximooz

I found this tool off another thread: http://www.ajdesigner.com/fl_tire/tire.php

sflgator

FYI guys...

Just bought and had them put on a set of Michelin Pilot Sport A/S Plus tires on the front to match the rear (265/35/18's); went with the 245/40/18's on the front and all I can say is "wow...these sizes are what the C63 AMG should've come with as oem." My car looks like it's been dropped; there's very little gap now in the front as well as the rear! Looks great, imho.

propain

I went with the Hankook Ventus V12 Evo. 275/35/18

They fit perfect and totally fill the gap. 2nd best rated tire tested on Car and Driver.

KCviper

Let us know what you think about these Hankook's. I'll be due soon........

c63canada

read this article by car and driver

http://www.caranddriver.com/reviews/...r_spec_page_11