SLK R172 AMG Wheels - help/advice

[Fangio246]

Hi all
First post.... Help and or advice required.
My wife has a beautiful R172 SLK 250 CDI AMG. We liked the AMG styling so only ever test drove this version and as with most test drives didn't spend that long driving the cars we saw.
Now in ownership we find the ride overly firm which for us spoils the car on long journeys - we bought the car to do European road trips! She came to the SLK after two MX5's which we did four 3,000 mile European trips in. Plus I have a Lotus Exige, which is obviously a much more focused sports car, yet has better ride quality than the Merc!

I think it's a shame Mercedes chose to put stiffer springs and dampers on the AMG version but feel changing these is probably a bridge too far!

My idea to improve ride quality is to drop wheel size to 17 inch, or even 16.

Question: has anyone out there tried this and what's their verdict. Or is there anyone in the West Midlands area with a standard R172 with 17 inch wheels who would let me try their wheels on my wife's car for half an hour to evaluate if this will be sufficient?

 

[GlosRichCLK]

Is there clearance on the front brake disks/caliper for smaller wheels?

If you look in the manual it should show the wheel sizes that are suitable for that model, or pop the car details into here for a list of the wheel/tyre sizes.

 

[John Laidlaw]

Before going toooo far, have you checked and are you using the factory tyre pressures?
Generally these are set really high to attain the over optimistic MPG figures- try dropping the pressures a few psi and see how it feels.
Otherwise to check on changing a wheel or tyre set up you can use this..

http://www.willtheyfit.com/

 

[John Laidlaw]

Before going toooo far, have you checked and are you using the factory tyre pressures?
Generally these are set really high to attain the over optimistic MPG figures- try dropping the pressures a few psi and see how it feels.
Otherwise to check on changing a wheel or tyre set up you can use this..

http://www.willtheyfit.com/

 

[LostKiwi]

There are 16s and 17s listed for your car so in theory it should be OK but... there are 344mm and 322mm diameter disks fitted. If you have the former then 16s will fit. If you have the later 17s may be your minimum.

From a personal experience perspective I went from 16s to 17s to 19s on my 210.
There was a sizable degradation in ride from 17s to 19s but a barely noticeable (though still present) one from 16s to 17s.

 

[Fangio246]

Thanks for the replies.
Firstly I tend to run my tyre pressures slightly below manufacturers recommendations, that said I appreciate different tyre brands and models can help. Just don't think this will enough for our liking.

I don't know without checking what disc size I have but know I can get at least 17's on the car.
This is why I wanted to try someone's 17's to see if there was enough of an improvement to warrant going down this road.

Still after someone in the West Midlands, Worcestershire, Warwickshire, Gloucestershire area with a standard R172 SLK running 17 inch wheels who wouldn't mind me trying their wheels/tyre combo out for half an hour....

 

[John Laidlaw]

No worries, hope someone will turn up for you, as you say it would be a better real time feel!

 

[LostKiwi]

You're more than welcome to try my wheels I have on my 210 (from a 211 E Class originally). They are 17s but shod with bigger tyres than you would use (245/45/17 as opposed to 225/45/17).

I'm in Daventry if thats any good.

 

[Fangio246]

Hi LostKiwi
Thanks for your offer, really appreciated.
Couple of problems, firstly your wheel/tyre combo will be 15mm plus larger in overall diameter than I'm currently running. Plus I would like to try a similar width setup, 7.5 J width front and 8.5 rear, as is used on the standard R172 SLK running 17 inch wheels.