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Hi guys,
I have a 2010 E350 sport sedan with 18 in AMG wheels with tire size 245/40/18. As cool as it looks, it is a painful ride over NJ potholes. I have also replaced the tires with run flats which doesn't quite help either.
Therefore I have decided to get 17" rims but I see the standard recommended tire size is 245/45/17 which is barely different from the current tire size.
Any recommendation on the biggest sidewall I can get 17s for this sedan? I just tried 225/55/17 (from an old S) and they fit. But before I buy new tires for the (old) 17inch rims, I would like to get some advice and recommendations. I do want to stick with the run flats though.
I run 225/50/17 in the winter and that gained me 0.6" additional sidewall with a 1% speedo variance (versus the 0.5" gain of the 245/45/17. Still not much of a gain. 235/50/17 would gain you 0.8" sidewall with a 2% speedo variance. www.tiresize.com is helpful in comparing different sizes
Is yours a 4matic? If so you might be able to go down to 16". 17" is the smallest that will fit due to front lower ball joint clearance.
The horrible ride is due to the run flats. They were standard on some other years and many people got rid of them and the ride was much better afterwards. I have the 245/45/17. They're fine, but I have the regular suspension not the sports. Still have had a few bent rim and a few flat tires. Not as bad as the 18 inch rims I have on the my W211 though. So far in 6 years, two flat tires and two bent rims on the 17 inch ones.
Tires are hugely different from each other depending on what you like. If you're running UHP A/S tires, some tires like the DWS06+ or AS4 can be pretty plush, or on the other hand the Goodyear Exhilarate A/S or Bridgestone Potenza 980AS have incredibly stiff sidewalls which handle subjectively really well (it's more for sharp, crisp turn-in, not absolute grip) but you get a ton of feedback. Run flats are awful though, it's where most of your problems come from. I would just get a AAA membership and run nicer tires. The run flat is an INCREDIBLY hard and dense sidewall that holds the tire up even in the absence of air.
A little bit of sidewall height isn't going to make or break your situation, it's really bad to go super low profile on big 19" wheels sure, but the S class makes do with big ol' wheels these days.
Thanks. I think this is what I needed.
Now, based on everyone's responses, I guess, using non run flats is the next best thing to do. I guess I will give it a shot.
The rims I have are from a 2004 S class... I think they will do just fine. Thank you
the other thing to watch when you fit a custom tire size is the tire's load rating. the stock tires are XL, extra load. these are quite heavy cars.
the stock 245/45R17 XL's, like the Michelin Pilot AS4 I'm running, have a load rating of 99, which is 1709 lbs per tire. The stock 245/40R18 XL are load rating 97, 1609 lbs.
and yes, runflats are *AWFUL*. my son bought a BMW 530xi that came with runflats, and replaced them with regular tires and the car rode and drove 10X nicer.
Thanks. I think this is what I needed.
Now, based on everyone's responses, I guess, using non run flats is the next best thing to do. I guess I will give it a shot.
The rims I have are from a 2004 S class... I think they will do just fine. Thank you
Non run flats with lower tire pressure would help significantly, try it.
Btw, did you say you tried 225/55/17? This gives bigger diameter than the normal/suggested tire size, if that really fits l suggest you go for it.
Right now I'm running 225/55/16 tires with 32psi, and l already changed the springs from 677 to 485 ( comfort) , l still don't 100% satisfy with the ride quality.
the US versions can't fit 16" because we get the larger high performance brakes in all versions. we don't get the E250 etc. tell ya what, i had to nail the binders pretty hard this afternoon, came around a bend and 60 MPH was suddenly full stop. the guy behind me was diving for the right shoulder, so I stayed to the left of my lane to give him extra room if he needed it my wife freaked out. the e350 luxury wagon with the 17s and undrilled rotors and a fresh set of michelin pilot as4 was flawless in the wet weather, there was zero drama, just some annoyance at the idiots who triggered it by bad driving.
I don't remember if it was mentioned in this thread but I had the same problem. This winter I decided to inflate cold at 41psi and haven't had any issues since. I live in Morris County and commute to Harrison, so yea.... roads. It's a lot cheaper than changing anything and it will improve the sporty drive also, if that matters to you.
I-287 has also claimed a few tires so I do understand your frustration.
I guess you have a very good ride now, don't you? Since your W212 is already a "luxury" which has the softest suspension setup, and now you have 235/50 tires!
Yes more air volume and rubber than alloy improve suspension to bumb road or pothole. Larger rim only good in eye but bad for your car longetivy it bent or crack rim, shortened life of strut and shock breaker and it also damaged front drivesaft joint to front diff and to transfer case so it cost too much for look cool. In 150k miles bend and crack wheel 5x$150= $750. Damage to front drive shaft and catalituc converter and oxygen sensor cost $2500. Damage to ujoint of front drive shaft almost cost $8000 plus to replace transmission because for dealer they only replace whole trans which include tranfer case. But i save to do diy buy the part from germany and replace it myself so the cost including tools around $1800. Smaller rim will definitely protect the car that the reason car used tire not band of rubber for car with larger rim.
Yes more air volume and rubber than alloy improve suspension to bumb road or pothole. Larger rim only good in eye but bad for your car longetivy it bent or crack rim, shortened life of strut and shock breaker and it also damaged front drivesaft joint to front diff and to transfer case so it cost too much for look cool. In 150k miles bend and crack wheel 5x$150= $750. Damage to front drive shaft and catalituc converter and oxygen sensor cost $2500. Damage to ujoint of front drive shaft almost cost $8000 plus to replace transmission because for dealer they only replace whole trans which include tranfer case. But i save to do diy buy the part from germany and replace it myself so the cost including tools around $1800. Smaller rim will definitely protect the car that the reason car used tire not band of rubber for car with larger rim.
Hey guys
Just an update. I bought 235/45/18 NON run - flat tires and the car drives beautifully. It feels like an E class again.
Thank you 🙏🏼 for all the input.
i've been running 235/50/17 for couple years now, they are pretty comfy. The only downside is, if you have to use a spare as it is smaller. So i just carry compressor and a tire plug kit, had couple of nails that are faster to patch then to get the spare on.
the US versions can't fit 16" because we get the larger high performance brakes in all versions. we don't get the E250 etc..
My E250 Bluetec accepts 16" wheels just fine.
I am keeping 16" wheels from W211 for potential use on W212, but I have good tires when we don't drive much, so probably another 4 years till my tires age.
I did not have good luck with 17" wheels. When human perception with comfort is pretty lousy, I think tire quality plays bigger role, than sidewall dimension.
Meaning I was happier with 18" tires and much bigger choice of tires.
My car does not have space for spare, but I bought donut-sized wheel from other MB model and am carrying it in the trunk. Driving 150 miles stretches between tire service on 120F desert is not making you want to wait for tow truck.
i've been running 235/50/17 for couple years now, they are pretty comfy. The only downside is, if you have to use a spare as it is smaller. So i just carry ompressor and a tire plug kit, had couple of nails that are faster to patch then to get the spare on.
Instead using donut as spare which had limitation i just get 5th wheel and tire same size as the other four. It fit on the trunk
last flat I got was a sidewall tear from clipping a curb. wasn't repairable. it was a slow leak, so I could inflate the tire and drive around a day, they'd be low the next morning. had to get 4 new tires as the old ones had just enough wear as to not be compatible with a new tire, and this let me switch from the awful harsh noisy ContiProContact MO it came with to the Michelin Pilot AS4 I much prefer, both in 245/45R17 XL. My wife (the primary driver) agrees the Michelins are much quieter and smoother, so we're *BOTH* happy
04-15-2022, 05:06 PM
Tire size question
