E55 KEV

Most AWD cars do not have staggered wheels, not even the 450HP 2004 Audi RS6.

I did not think it was possible for AWD cars to properly use a staggered setup because of trasfer case issues or something. However, I see the 2004 S-Class 4Matic has the AMG Sport Package option which includes:

245/45/18
265/40/18

Kar don

Must be a typo, a friend of mine has a 03 4matic sport and it has 245/45 all around on 18x8 rims.

E55AMG99

AWD cars can use staggered tires/wheels. While most use the same size all around, the 911TT is AWD and has a staggered tire/wheel setup. If you choose to switch to a staggered setup, the diameters must be as close to exact as possible. It is less critical and sometimes preferred with viscous coupled drive systems. Again, the 911TT uses a slight difference in rolling diameter to send 5% of the power up front and 95% to the rear (until traction is lost). If the front and rear were exactly the same, 100% would go to the rear wheels until the speed of the front and rear tires started to differ.

scorchie

Some of the new Mercedes cars with 4Matic are now coming with staggered setup. Interestingly, many of these come with tire diameters that are quite different on the front and rear--if nothing, at least not the tire sizes that would be closest. I believe the E500 4Matic and the S500 4Matic are available with a staggered setup with 265 rear tires. The 275 in the same profile would be a closer match for the 245 tires. It's even visually discernable that the rear tires are smaller, especially on a car like the E55.

-s-

Luke@tirerack

it's all about tire diameter ... and the way in which the all wheel drive system is design but, in your example both the front tires and rear tire are 26.7" tall (and it is exact tire specific) ....... and they utilize a viscous coupling system which allows a little slippage between front and rear unlike the RS6

steve s

some of the awd systems are normally 95% front and 5% rear... especially those that were created from fwd originally...these tend to keep the rims at the same width... a difference in tire width can cause slippage and overheat/wear out some of the mechanicals in the awd...

E55AMG99

I think Honda CRV is front biased this way and uses clutches to transmit power to the rear but what does "width" have to do with slippage between front and rear wheels?

steve s

it's hard to keep the same tire diameter with different widths... thickness of a tire wall is determined by the aspect ratio... aspect ratio is by definition relative to tire width...

take my c36... front tire is 225-45-17...rear is 245-40-17... the rear is actually a little smaller than the front..

some awd systems detect a difference in tire rotation between front and rear while travelling the same distance...which a different diameter tire will do... this may cause the awd to think there is slippage and a constant use of the system trying to compensate for this "slippage" may cause excess heat and/or excess wear...

this is one of the reasons why many awd manufaturers recommend changing all four tires at the same time, and not only one... and keep all four tires the same brand/same line rather than mix and match...

E55 KEV

Tire Rack list E-Class and S-Class with and without 4Matic with TPMS. What is that? I can't find that describe on MBUSA.com?

Lynn

Tire Pressure Monitoring System

E55AMG99

I see what you are trying to say. It is hard to keep the same diameter when changing one or more of the variables. A closer numerical match would be 225-45-17and 255-40-17. The rolling difference is less than 2 revolutions per mile. Believe it or not, this difference is as close or closer than some mass produced tires within the same make/model line due to mold variances. Vehicle load distribution and disparate tire pressure front to rear will also cause differences in rolling diameter as great or greater than the example above.

The buildup of heat and excess wear due to front/rear rolling diameter differences is entirely dependent on the type of system used to transmit power fore and aft. Viscous coupled drives systems are immune and even have a difference built in for "pre-load". Direct gear driven with or without clutches are not.

E55AMG99

I see what you are trying to say. It is hard to keep the same diameter when changing one or more of the variables. A closer numerical match would be 225-45-17and 255-40-17. The rolling difference is less than 2 revolutions per mile. Believe it or not, this difference is as close or closer than some mass produced tires within the same make/model line due to mold variances. Vehicle load distribution and disparate tire pressure front to rear will also cause differences in rolling diameter as great or greater than the example above.

The buildup of heat and excess wear due to front/rear rolling diameter differences is entirely dependent on the type of system used to transmit power fore and aft. Viscous coupled drives systems are immune and even have a difference built in for "pre-load". Direct gear driven with or without clutches are not.

E55MKB

Kev:

My 993turbo uses staggered tire fitment. fr are 225-40/18 and rr are 285-30/18. The car uses viscous center diff meaning the diff will increase locking when slippage between fr and rear axle is detected. In other word, heat due to the slippage will increase viscosity of the silicone fluid in the viscuos diff which in turn causes less slippage/more locking between fr and rr axles.

Porsche purposely chose the fr and rr tire size not to have the same diameter (fr slightly bigger than rear). Remember that the car is mostly rear wheel biased but as the car gain speed, the difference in tire rotation between fr and rr axle generate more heat in the center diff to cause more locking between fr and rr axle which in turn increase straight line stability at higher speed.

There has been some cases of owner putting even larger/wider front tires on 993tt (to reduce understeer) without really taking consideration of the diameter issue and resulted in burned viscous center diff.

steve s

yeah... it really depends on how it was originally set up as...

WannaBeAMG

read the fine print. in the brochure it sais when equipped with 4matic its 245/45/18 all around. i thought there used to be the same disclaimer on mbusa.com too but i didnt see it.

E55 KEV

I thought that was the staggered setup was too good to be true. If that is the case then Tire Rack needs to update their recommention on the staggered setup for 2004 S-Class on their website.

Tire Rack list staggered setups for 2004 E-Class sedans and wagons also. Their are no staggered setups for the W203 nor the W210.

That is where my confusion started - why are their Tire Rack suggested staggered setups for the 2004 W220 cars and not the 2003 W220 4Matics? Tire Rack also shows staggered for 2004 W211 4Matics models and not for any W203 or W210 4Matics.