Gremlin9

There is no clear definitive answer based on my searching for PSS rear tires on 18 inch stock wheels (there is a clear preference for 245s on the front)

Please evaluate these 3 factors:

1)Appearance

2)Function/Grip/Drivability

3)Rubbing

Does anybody have any pics from the rear to see how wide these tires look?


Thanks.

b16

I think this has been beaten to death in this forum, but here we go again..

1.) This is subjective, I think it looks fine.
2.) Both work the same, you'll get a little more grip from 275's having a larger contact patch.
3.) No rubbing with either on stock wheels with stock suspension.

Here is a photo of my 275 PSS on my stock wheels at stock height.

SonnyakaPig

I know I'll be shot down for this thought, but maybe it's worth considering that AMG chose the stock tire widths for a reason.

I'm not passing judgment on anyone that runs wider tire widths on the stock wheels. But, it just seems to me AMG felt 235/255 was best for handling.

If it were me and I wanted to run wider than stock rubber, I would go 265's.

b16

Yes, and that reason is cost and packaging.

The rear tire size is the same on the regular C class (with optional 18's)

SonnyakaPig

Probably, but not necessarily.

It would be interesting to know which width AMG uses in their driving academy cars. I think cost and packaging would be less of a factor for the upkeep of those vehicles.

Even if cost and packaging is the primary reason, that doesn't negate the possibility that altering the tire width from OEM specs may change the suspension geometry somewhat.

bhamg

The nice thing about 265's on the rear is that the tire is the same height (overall diameter) as the front 235's. 255's are 0.4" smaller in OD than the 235's.

SonnyakaPig

That's very specific information. I appreciate learning that.

I would then ask, is that leveling in height preferable to the stock dimensions?

My next question would be, what happens to the relative height (front of car to rear) when you install 275's instead of 265's?

bhamg

The first week I owned the car I thought the front tire just looked a little tall in relation to the rear. When I checked it out on Tire Rack I was actually surprised to see there was so much of a difference. IMO 265's give the car a subtly more aggressive stance...perhaps it's my imagination but I think not. Everyone who uses 275's in the rear does so in conjunction with 245's on the front so it would be the same relatively speaking as 235/265. I went from OE P30 to coilovers anyway so I guess it's a moot point now.

SonnyakaPig

I ran 235/265 once. I wasn't looking at the stance then, though, so I didn't notice a difference in appearance.

irablumberg

Does the change in tire size (larger than stock) affect the speedo / odometer in any meaningful way? Does it mess with the traction control or stability control?

TIA,
Ira

Gremlin9

Anybody have pics of 275 pss from directly behind the car so that we can get an idea of how beefy they look?

Thanks.

Gremlin9

Originally Posted by hhughes1
Tread width for the 265 is actually listed as wider than that for the 275. Mounted on 9" wheels will likely yield a larger contact patch with the 265. Additionally any decrease in sidewall height looks better in my point of view especially with the drop from the H&R springs. I have run the 265/245 combination for several years now and just feel comfortable with it on the stock wheels.


Comments?

How is it possible for 265s to have a larger contact patch than 275s???

bhamg

No and no. The difference in the speedo reading going from 255's to 265's on the rear is 1 mph lower at 70 mph, so given the (on the low side) error engineered into the typical speedo you are closer to true speed with the 265's.

cyberorth

Every manufacturer releases spec sheets for all of their tire models. These are available at their website for all to see. The exact dimensions of every size of every model tire of every manufacturer is specific to that exact tire. The general width/height/wheel diameter sizing is for classification or reference only. Even two EXACT tires of the same size may be different in that one maybe oe for one car and the other for general use.
I am baffled by how often people overlook this matter, even car techs

cyberorth

Of course AMG academy uses the oe contis because continental sponsors the event. They have conti tires coming out of every orifice. They go through those very often. Even more so at the AMG day events where they let people do laps for free.

Your point regarding suspension geometry is valid, but I doubt if that applies to the c. May be sls.

Imo, It is only in the case of low volume production cars like the exotics that tires are selected for specific performance. For our cars, it's a matter of which tire manufacturer wins the bid. Again IMO, both Pirellis and contis that are oe for c63 are inferior compare to what is available.

Gremlin9

Thanks for the pic, looks great!

Can you comment on this post regarding the contact patch?

Originally Posted by hhughes1
Tread width for the 265 is actually listed as wider than that for the 275. Mounted on 9" wheels will likely yield a larger contact patch with the 265. Additionally any decrease in sidewall height looks better in my point of view especially with the drop from the H&R springs. I have run the 265/245 combination for several years now and just feel comfortable with it on the stock wheels.


Comments?

How is it possible for 265s to have a larger contact patch than 275s???

bhamg

My car was delivered with Pirellis. My spare wheels are now a new set of the OE split-5 spoke wheels with Contis. IMO there is no comparison between the two tires. The P Zeros were a thoroughly average tire in all respects. The Contis IMO are a vastly superior all-round tire, lots of grip in the dry and excellent wet weather braking and cornering performance, as I found out during the recent heavy rains here.

khmergod

I and many others run 275 rears. Will run 245 front when oe tires wear out. No rubbing that I know of. Clearance on inside well is very small. I think that is max width for stock offset without spacers.

rory breaker

There was a guy in some older threads who talked about buying 275s and returning them because of the sidewall size. Specifically the PSS'. Don't know if he posted pics but do a search and you may find them.

Keithb

I put Conti 265's on the rear of my car and they look and behave quite nicely. Almost didn't, as while they were getting installed a somewhat rookie put the wheel back on and came in to tell me they were rubbing. When I went to look, omg, yes they were rubbing the inside fender well - when the wheel was hanging with the car on the lift (what a dimwit!) He had a hard time believing that they wouldn't rub when the car was on the ground. Fortunately the owner (also an AMG owner) was there to keep him in line.

khmergod

Th sidewall is a little "fat" on brighter colors such as silver and grey. Can't even tell on my red.

Mort

Check the specs on Tire Rack http://www.tirerack.com/tires/tires....ot+Super+Sport

and you will see the tread width on the 265/35/18 is 10.1" and for the 275/35/18 is 10.0". Therefore the contact patch is slightly larger for the 265. The 265 or 275 refers to section (total) width of the tire on a measured rim width, thus the tread width can vary depending on how square or rounded the shoulders are on a particular tire. You will see the section width of the 265/35/18 is 10.7" and for the 275/35/18 is 10.9" so it is larger in section and how the tire size is rated.

Gremlin9

If this is the case, then why would anybody put 275s on the stock 18 inch wheels?

Wouldn't 265s give better drivability and traction since the tread width is more important than the section width?

Or is the section width more important than the tread width for traction and drivability?

I am very confused...

Chocofishez

Here is how 275/245 looks on my palladium.

The sidewalls are definitely larger and give a beefier look, but I don't mind. C63s aren't being sold as nimble corner carvers, but rather as refined muscle cars. I think the fatter tires fit the theme well. I love this setup.

bhamg

It's worth noting also that the measured rim width for both sizes was 9.5" which makes a very persuasive argument for going no larger than 265 in the PSS on OE wheels.