Are they to bit wide

[Stulc]

Or no...I was looking at 18 inch wheels for an 06 W211 E220 estate/wagon but the front tyres are 245/35 or 40/18, the backs are 275/35 or 40/18 but would like 225/45 or 50's all round. I just that 1..i'll feel every rut, pot hole, bump with the wide ones, 2..how much do the wide ones affect mpg.

 

[s5tuart]

Or no...I was looking at 18 inch wheels for an 06 W211 E220 estate/wagon but the front tyres are 245/35 or 40/18, the backs are 275/35 or 40/18 but would like 225/45 or 50's all round. I just that 1..i'll feel every rut, pot hole, bump with the wide ones, 2..how much do the wide ones affect mpg.

If you go with bigger wheels then avoid potholes like the plague or the wheels will likely get cracked.
Larger sidewalls are your friend on out UK roads.

 

[Stulc]

Yes i know, how much of a difference (less) in mpg could i expect.

 

[SL63 Mark]

I don’t know, is there a guide on the internet somewhere ?

 

[Blobcat]

Used to have 17" 245's all around on my W211 E320

 

[Stulc]

How did they affect the mpg as i don't imagine 18s would be much different from 17s, or are they

 

[s5tuart]

How did they affect the mpg as i don't imagine 18s would be much different from 17s, or are they

Lower profile tyres will compromise fuel economy.

Low Profile Tyres - Advantages and Disadvantages

Cars on roads with larger alloy size or rim size than the standard ones is quite a common sighting nowadays. These upsized alloys or rims are blessed...

www.tyremarket.com

 

[Stulc]

I know they do but by roughly how much as i said.

 

[Blobcat]

How did they affect the mpg as i don't imagine 18s would be much different from 17s, or are they

I averaged >36mpg for 100k miles (calculated from fuel receipts) - very comfortable good wear ~30k miles per set

 

[Stulc]

I think you meant mpg, that's with 17s so 18s will be worse, maybe not that much but will be worse.

 

[sonic]

My E350CDI is on standard summer tyres 245's & 265's 18" Winters are 245"s all around on 17", which I much prefer.
The wife's SLC250 came on standard 225's & 245's 18". But I have changed them to 225's all around all season 17" tyres, which I again much prefer.

 

[Blobcat]

I think you meant mpg, that's with 17s so 18s will be worse, maybe not that much but will be worse.

Yes mpg… fixed it now.
Wider tyres generally reduce the economy

 

[Stulc]

i know but can't find out by how much with 245 18s all round

 

[LostKiwi]

On my old 210 I went from 225/16 all round to 245/17 all round and it dropped around 8%

If changing away from standard sizes don't forget to notify your insurer.