DNAPoPo

Car is a 2010 W212 E550.

If you were to pick out 20" wheels what specs would be ideal in your opinions?

I'm thinking along the lines of:
20x9 et35 fronts with 255/30/20 tires
20x10 et54 rears with 285/30/20 tires

What would you guys change?

Thanks in advance.

DNAPoPo

Where are the wheel gurus?

bighman

I think the offsets for the rear may be too high...also rear tires should be 285/25/20

DNAPoPo

Yup, that is the correct size for for same diameter in rear, but I was actually told a 30 would fit, so I am leaning towards it for a smoother ride.

ohlord

tire sizes wrong
20's just plain wrong
And actually neither rear profile matches the dia.

the one you think would be smoother is more wronger than the other suggested.

DNAPoPo

I guess it would help if you provide something more right instead... I'm open to any suggestions as I am no expert.

ohlord

But a 9 front on a 30-35et rim in 245/35/19 and a 9.5 on a 52et in 285/30/19
are within 1 rev of each other front and rear and 10revs per mile off the oem sport diameter.
There are reasons Mercedes did not use 20's and Your suspension etc. is not destined for them either.Proceed with caution if you do choose to go with 20's
your ride quality will vanish, handling will be compromised,and you will be dodging every pothole from La Jolla to Pacoima
You can always Email Luke at tirerack.com for fitment suggestions.
A 255 on the front might fit with fender rolling but why go there if not needed.
Are you planning on lowering the car?

threeMBs

All the info you seek is already available by checking W212 forum. It contains many threads on the subject.