Highest tyre profile.

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C240 Sport

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Tunbridge Wells
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Mercedes benz cls 320 diesel 2006
I have a 2010 Eclass 350 Spt Blueefficiency Cabriolet. Front tyres are225/40 R18 Rears 255/35 R18.
What is the highest profile i can go on these tyre?
 
Hi , in the first instance I would look at handbook supplied with the car. Mercedes put the tyre data under the fuel fillers but don't know what model year.
 
Hi , in the first instance I would look at handbook supplied with the car. Mercedes put the tyre data under the fuel fillers but don't know what model year.
Yea I've looked in the handbook at the different tyre sizes but I was wondering if you could up the profile on them for a smoother ride.
 
Yea I've looked in the handbook at the different tyre sizes but I was wondering if you could up the profile on them for a smoother ride.
Not without reducing the rim diameter accordingly. There are many online comparison calculators to show the different possibilities.
One needs to keep the overall rolling circumference the same otherwise the will be speedometer errors
Keep in mind any deviation from the sizes shown in the handbook would need to be notified to your insurer.
 
Yea I've looked in the handbook at the different tyre sizes but I was wondering if you could up the profile on them for a smoother ride.

Nothing about tyres will alter the comfort apart from changing to comfort suspension, shocks and springs. Then maybe go to 17 inch rims , which TBF will just look silly on the car.
 
Nothing about tyres will alter the comfort apart from changing to comfort suspension, shocks and springs. Then maybe go to 17 inch rims , which TBF will just look silly on the car.
Wouldnt a higher profile on a tyre give you more sidewall so the ride wouldn't be so harsh.
 
Wouldnt a higher profile on a tyre give you more sidewall so the ride wouldn't be so harsh.
Fwiw I know someone who has done precisely that, for exactly that reason (and after replacing a number of cracked alloys, that had suffered from the blight of Potholed roads).
He is adamant that it does work. No more damaged alloys since, and apparently a softer ride.
Not an MB though, he drives a Toyota and went from 45 to 55 profile.
Hth.
 
Fwiw I know someone who has done precisely that, for exactly that reason (and after replacing a number of cracked alloys, that had suffered from the blight of Potholed roads).
He is adamant that it does work. No more damaged alloys since, and apparently a softer ride.
Not an MB though, he drives a Toyota and went from 45 to 55 profile.
Hth.
Sounds good to me.
 
Wouldnt a higher profile on a tyre give you more sidewall so the ride wouldn't be so harsh.

The short answer is yes if you want a monster truck look. Drop to 16 inch rims should do you nicely.Screenshot_20230713-185247.png
 
As others said.

If you're keeping the 18" rims, you have very limited options.

The only way to get higher profile tyres without upsetting the factory setup is by replacing the 18" rims with 17" or 16" rims.
 
All these internet threads that believe higher profile tyres are the answer don't take into account just how bad and how big potholes are these days.
I've had cars with 19" wheels, 18" and 17", a Renault Kangoo van with 14" steel wheels that all buckled after hitting potholes and I've had a Ford Ranger with 16" wheels and tyres that looked liked balloons, none of higher profile tyres coped with the state of today's roads.
In fact, the two cars with 18" and 19" wheels are the only two that never needed any repairs, and the one with 19" wheels is more comfortable than the one with 18" wheels.
 
The tyre and the pressure you inflate them to is also a factor.

Some have sidewalls that are very solid, whilst other tyres are more compliant
 
In my experience the larger the sidewall the quieter and more comfortable the car is.
As others have said the only way to increase the size of the tyre sidewall and retain the overall diameter/circumference of the tyre is (pretty obviously) to reduce the diameter of the wheel.
As an example a 195/65/15, 205/55/16, 225/45/17 and 225/40/18 will all have about the same outside diameter with different rim sizes. There will be a minimum size rim that will clear the brake components - usually the smallest size rim that will fit will be shown in the car handbook under the winter tyres section.
 
My 2010 A207 came with copy AMG 19 wheels and very low profile tyres. I got sick of them and bought some genuine MB 17 from eBay. The coupe style cars do look better with the big wheels but they have questionable usability in the uk. Depends what you use/need the car for. The ride definitely improved with the 17s and higher profile tyres and surprisingly I think it handles better. Much more progressive.
 
If Mercedes did not make their wheels from a biscuit/chocolate alloy it would not be an issue what size the wheels were!! I only rarely hear about pothole wheel damage on other forums for other marques I'm on.
 
If Mercedes did not make their wheels from a biscuit/chocolate alloy it would not be an issue what size the wheels were!! I only rarely hear about pothole wheel damage on other forums for other marques I'm on.
Except they don't - Ronal (amongst others) make their wheels for them. Of course, it could be that Mercedes specify that the wheels Ronal make for them are fabricated from the finest German Kӓse!
 
Rather than blame tyres, the biggest change in modern cars lack of comfort is they all have rock hard suspension. Even high up SUV's corner without any body roll. You now rely on the tyres to do the job the suspension used to take care of.
 
Very true......Nurburgring lap times seem to matter more than comfort these days....which is fine on certain cars with RS, AMG or M somewhere in their name....not so much on a big comfy non sport E class.. That said I don't want my cars to handle like a pig on stilts either so there has to be some compromise. The more powerful cars get the less they will be able to cope on softer springs/dampers. You could get away with it back in the day when "fast cars" were 180 or 200 horse and 1300kg....not so much with 3 or 4 hundred dobbins and 1750 plus kg.
 

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