biker349

i have a 2004 mercedes cl600 with the staggered wheel set up. my front tires are 265/40/18, my rear tires are the low profile tires that come with the staggered set up from the dealer. whenever i drive the rear tires are very unforgiving when going over speed bumps, pot holes and uneven surface. also drivers keep waving at me telling me that my rear tires are flat. i would like to put bigger tires on the rear wheels to stop some of these problems. what do you think would be the biggest tire and biggest sidewall that i could put on the rear wheels without any modifications to the cars body. i think the size of the sidewall is the thing that would solve the problem.
any thoughts, or feedback is greatly appreciated.
thank you

renault12ts

Your standard front tyre should be a 245/45 18. Your standard rear tyre will be 265/40 18. It does seem your car came with the wrong front tyres and probably the wrong rear ones too.