yavor

I'm wondering about leaving my 20'' 9J rims with 265/45/20 tyres only for the winter ones and switching to 21'' for the summer. The problem is the only original rims wider than 9J are the ones for the GLE63, which has wheels with a different offset. I'd like to drive with 295/40/21 tyres which should give a bit more comfort thant the OEM size 295/35/21. Has anybody has any idea if the rims from GLE63 that have ET46 will stick too much out on a normal GLE 350d with the more agressive offset/ ET 46 for GLE63 compared to ET 53 for the normal GLE + 1 inch wider rim?

E55 KEV

295/40/21 is too tall and will cause a large speedometer error. google tire size calculator for details.

yavor

The wheel radius will be 11.5 mm larger than with the OEM size, which means the vehicle will be 1cm taller that I don't think is so much, the difference in the height of the tyre sidewall is similar if you drive inflated to 2.2 bar /as recommended on the fuel tank door/ or if you drive at 2.6 bar for instance. The speedometer error will be 3% which is also not bothering me, the question was more if this setup will harm the suspension or something on the car and also I was hoping somebody has tested these rims because what bothers me is if the wider rim with smaller offset will protrude too much out of the wheel well or not. And also what change in fuel consumption to expect going from 265 to 295, neglibile or not?

E55 KEV

There should not be any problems doing a plus-1 rim upgrade from 20 to 21 but it may be hard finding someone who has put the wrong sized tires on their W166 to be able to answer your questions. Most owners prolly stay within the recommendations. A 295/40/21 is 2 inches or 50mm taller than a 265/40/20.