[justa]

Just how much comfier are 17" rims compared to 18" ?

Is there a noticable difference ?

[mithiral67]

difference between 17 to 18s is about a tenth, imo, of the difference between 18s and 19s. You likely can't tell the difference unless you compared them back to back.

[Merv B]

My wife has 18s on her Civic and you can feel every bump in the car compared to my bm which has 17in runflats. You still feel them but not as much and it put me off getting a set of 18s for summer and keeping the 17s for winter rubber.

[giotecno]

the e92 m3 18" wheels I got were lighter and more smoother ride than my std 17's so depends if you get the right one mate, also if you switch from runflat to non makes a difference too.

[E92westy]

I'd also add that my E90 on 18's feels better* than my old E92 on 18's.
Both M Sport, both on RFT.....
Go figure.


*thats for 'comfort' and the handling doesn't seem to suffer, but I'm no Stig

[Em135eye]

TBH there's no firm conclusion. Some prefer 17s, some prefer 18s. Try both if you can and decide for yourself! I prefer 17s but I am a bit of an oddity on E90post...

[SO8]

I have found the 19" wheels on my 2010 e92 330d far more comfortable than the 18" ones on my 2008 e92 320d ..... its not just the wheels and tyres but the whole way the suspension is set up ....

[p0jy]

Hi Justa,

I thought you were selling your car?

I prefer the ride on 17s, but 18s do look allot better!

[HighlandPete]

Originally Posted by SO8

..... its not just the wheels and tyres but the whole way the suspension is set up ....

+1

And that is what makes it difficult to say how a particular car will ride, on a given wheel size.

Generally though, a 17" will ride better than a 18", with the same suspension and same tyre brand/spec. Even within a size, different tyres will change the ride quality. Changing to a winter tyre can show this, as typically the same size winter tyre is more comfortable.

Remember each tyre has a spring rate, (well actually as we drive, an ever changing spring rate) so it is part of the total suspension spring rate. One factor which influences comfort, is whether the resulting suspension frequencies and harmonics enhance or detract from the ride quality.

Don't forget tyre and rim weight are critical as well, to what feels best, as unsprung weight is a key factor in ride comfort.

HighlandPete

[kaishang]

I has an 18" M sport suspension loaner and hated it.

17" SE suspension is much better for me.

[Em135eye]

Originally Posted by kaishang

I has an 18" M sport suspension loaner and hated it.

17" SE suspension is much better for me.

+1 - almost.

I've got M Sport suspension on an SE with non RFT tyres. Works very well but not in wiv da kidz.

[ALF_E90]

When I switched from 18's to 17's (originally for winter tyres) the difference was such that sold the 18's and moved to 17's for the summers as well.

In my case this also involved moving from 255 rears to 225 all round, a valid option in my case without upsetting the insurance company since it is an SE not an MSport, and 225/45/17 all round is an option on the plate for summer and winter use.

The improvements were:

• Massively improved ride - particularly over very bad bumps such as speed humps, I laughed out loud the first time I went over some of these. It is now genuinely comfortable, not acceptable.
• Discovering that premium rubber like a CSC3 or F1 Asymetric was barely over £100 - I didn't really want to go down the 452 route on the 18's and premium are expensive for the rears especially, even non-RFT.
• The handling balance is significantly better, the rear end feels like it is working harder when cornering with no noticeable loss of traction from a standing start. I can much more easily play about a little with the rear end without feeling like it will jump out on me when not expecting it - I have to be trying.
• Less tramlining - particularly when putting the nearside wheel pretty much off the road (which happens a lot on local narrow country lanes when someone comes the other way) the car is vastly more stable.
• I can swap front to rear and wear out a set evenly then replace in one go, which personally I prefer.

Of course the narrower rears should be less prone to aquaplaning in the wet as well, which is IMHO the time a tyre's performance is most critical for road use.

Well worth it for me, but I appreciate the looks are more important than the dynamic benefits for some people - if I lived in a city, drove a coupe not a touring, and did a lot fewer miles then I might have kept the 18's!

[Jules59]

E91 330d LCI Msport.
I have 2 sets of staggered wheels with RFT tyres:

F 225/40/R18 88Y, 8J, ET34
R 255/35/R18 90Y, 8.5J, ET37
Michelin Pilot sport

and

F 225/45 17/8J/ET34
R 255/40 17/8.5J/ET37
Bridgestone Potenza

The 17" are much more comfortable; absorbing alot more bump & vibration from the road surface, The 18" setup is more precise in hard cornering (DTC or less driving style), but the difference here is not noticeable when driving gently. None of this is surprising really. But oddly I find the 17" setup has alot more tramlining - maybe due to different tyre makes.

I intend to replace the RFTs with non-RFT summer & winter tyres.

[Pwalo]

I recently fitted 18 inch ellipsoids after having 17's with non rfts'. As Pete states the 18s are heavier and increasing the unsprung weight gives the dampers a much harder time to control the wheels and tyre on rougher roads. My SE with 70 k on the clock suddenly felt like it had gone from a pair of Nike Air to a pair of Dunlop wellies. I the fitted Eibach Pro Kit Progressive Springs and Bilstein B6 Dampers and then it felt like the suspension was back in control. FYI the Fronts are running Bridgestone RFT RE50's and rears are on Bridgestone RE40 non RFT's. I despise the runflats but having blown al my savings fitting new bathroom means that the RFT's will be on for a bit longer. Without the RFT's up front I predict that my ride and comfort will be an acceptably compliant but sufficiently feedback compromise. I will be fitting the 17's once the salt goes down and wil be interested to see whether the cars handling dynamics improve - I sneakily suspect it will over a greater range of surfaces and conditions as I have laways thought the SE/LX variants of cars have always been more capable over a broader range of surfaces and conditions than the more focussed Sport variants. Will rport at the back end of the year