Can I run 255 50 19 up front and 255 55 19 rear on a 2wd 2011 ML350? I have 2 pirelli 55's that are new and want to put them on the rear. Will I screw up on board computer or tranny?

 

can't see how there would be an issue with either of the things you mention, however your speedo is going to be off due to the higher profile tires (higher than stock) in the rear.

 

Well I called Mercedes and spoke to Service rep. They did not recommend due to the sensors. I still do not see how it will mess with sensors but he said may get some weird codes.

 

which sensors? the pressure sensors? for what it's worth, I have found service reps NOT to be the final answer on several MB things.

 

I am not sure what sensors.

 

What the MB service rep is probably referring to is the wheel speed sensors...


The computer is looking for equal tire rotations on all four corners and a change in speed via. the steering angle to determine if you have traction, a wheel is slipping or one or more wheels locked. Minor variations due to tire wear are tolerated, but larger variations are not.


I bet the MB rep doesn't know the threshold so they have to say that it may not work.


The difference in diameter (from Pirelli/Tire Rack) appears to be around 0.75". That equates to about the 11/32" tread depth... so the computer will see about that maximum difference from brand new to bald tires. In lay mans terms it will most likely interpret that the front tires are about "worn out" and the rear are "brand new". Assuming the tires wear evenly throughout their life this difference should remain about the same.


If it were my vehicle I would give it a try... the worst case being I would have to pay to take off one set if the computer/ABS started to throw codes - but I don't think it will.


Hope this helps.

 

note - the OP stated this is a 2wheel drive ML. I bet this also confused the MB service tech. Don't come across these too often.