Rear axle tyres on C63

[akhan48]

Does anyone know if I can get away with using 255/35 winter tyres on the rear of my C63, as opposed to the 255/30 ones which are already on the car?

 

[bobbersmill]

Does anyone know if I can get away with using 255/35 winter tyres on the rear of my C63, as opposed to the 255/30 ones which are already on the car?

The new tyre will be 12.7mm too high. This will mean your speedo on the non stock tyre will be 4% too low.
Its not a great deal but I would keep them stock on a car like the C63.
Tire size calculator
Plug some combos into this site and you can see the effect of changing sizes. If you are not already aware the 30 number in the OEM tyre size represents a percentage of the width so the OEM sidewall is 30% of the width of the tyre ie 255 x 30% = 76.5mm (height of sidewall).
Hope this helps.

 

[akhan48]

Thanks for that, very interesting, I hadn't even considered that it might affect my speedo reading. Looks like I'll have to keep to the stock tyre size then.

 

[Toodeep]

Thanks for that, very interesting, I hadn't even considered that it might affect my speedo reading. Looks like I'll have to keep to the stock tyre size then.

Do it (as long as they physically fit which someone else might confirm). A European Union directive to manufacturers dictates that a speedo may read up to 10% higher than actual but not a single mile per hour lower. In effect, this means they err on the side of caution and the percentage error in your car may well be as much or greater than the under-read potential caused by your proposed change. In any case, the under-read, if any, is likely to be even more negligible than the 4% suggested (and reduce with wear). Even if this were not the case:

1 You could drive a couple of mph under the speed limit if that is a concern.

2 Weigh the consequences of an under-reading speedo against having the wrong rubber for the conditions.

 

[talleres]

My dilemma too

I'm interested as I have a similar dilemma and I plan to use the car all winter if possible.

Any thoughts on this? My spec has mixed size tyres on the 19 inch rims. Continental winter tyres (TS810), rated for 149mph, are £236 from mytyres for 235/35 R19.

However they don't offer Continentals for 255/30 R19. They offer instead Dunlop Wintersport 3D at £289. I won't mix tyres.So my dillemma is this. Do I:

1. Go with the option set out by the OP,

or

2. Get a set of 18 inch wheels and a matched set of winter tyres

Advice appreciated (and sorry if this is a thread hijack).

 

[whitenemesis]

What does the owner's handbook suggest?

 

[mika]

why not do 255/30/19 dunlop wintersport 3D on rear approx £280
and 235/35/19 dunlop wintersport 3D on front approx £ 250
not cheap but
standard size (i think)
same 19 "rims
thats what im planning

 

[talleres]

Whitenemesis, I haven't got it yet. Like Bobbersmill, I've changed my mind about my spec so many times I missed my October slot.

Mika Hakkinen, good idea - thank you.

I've had a long and happy time with Continentals but will look to using the Dunlops. Unless I can get a set of the standard 18 inch rims at a decent price as 18 inch wheels should be better in the winter, and It'd be easy to simply exchange wheels when I need to (I have the storage space).

 

[andy27168]

Hi,
If you change the tyre profile you risk your traction control system and cruise control not working correctly.

 

[The _Don]

I would try to stick to the original sizes.

 

[whitenemesis]

Just checked the interactive online handbook and there are no recommendations for winter tyres for the C63

 

[crockers]

If your speedo under reads so will the mileage. Could be classified as clocking.

 

[Palmball]

With regards to tyre size, the only non-stock size that's suitable for the C63 are 265/30/19 - this size makes next to no difference to the rolling circumference and is the tyre size I always use on the C63 (once the under-tyred 255 originals have worn out). You will find a lot more tyre choice available at this more popular and cheaper size too.

Winter tyre wise, just get a set of Vredestein Wintrac Extreme's! These are widely regarded as the very best winter tyre on the market, available at less than what is being quoted for other brands.

Camskill are selling at:

235/35/19 - £164 + postage
265/30/19 - £198 + postage

 

[akhan48]

Palmball, thank you very much, that was exactly the info I needed! 255/30 at the rears are a very expensive size! 255/35 are a lot cheaper so was wondering if I could use them, but I will take your advice and get 265/30 at the rear.

Thanks again!

 

[talleres]

Palmball, thanks from me too.

 

[bobbersmill]

Palmball, thank you very much, that was exactly the info I needed! 255/30 at the rears are a very expensive size! 255/35 are a lot cheaper so was wondering if I could use them, but I will take your advice and get 265/30 at the rear.

Thanks again!

Palmballs recomendation is nearer to OEM in that the sidewall will be 79.5mm tall vs oem which is 76.5mm. The 255/35 you are thinking of are 89.25mm tall meaning a) the tyre will become 12.75mm closer to the wheel arch b) increase the rolling radius of the tyre c) cause the speedo to read a lower speed than is actually being travelled.
You also need to check what the maximum width is that the rims can take with a knowledgable tyre fitter.

 

[G7Wagen]

I have 255/30 19's on my new E Coupe 350 CDi deliverey next week... (Rears) do you think the 265's you mention will fit my car as well... i've just pulled my hair out(and am nearly bald) trying to get a good priced set of 255's for my other car CLK 320 on 255/35/18's

 

[bobbersmill]

I have 255/30 19's on my new E Coupe 350 CDi deliverey next week... (Rears) do you think the 265's you mention will fit my car as well... i've just pulled my hair out(and am nearly bald) trying to get a good priced set of 255's for my other car CLK 320 on 255/35/18's

Radius wise as I said above its not a great deal different to oem but not being a tyre and wheel expert I would ask someone who knows if the slightly increased tyre width is okay for the rim.

 

[G7Wagen]

Radius wise as I said above its not a great deal different to oem but not being a tyre and wheel expert I would ask someone who knows if the slightly increased tyre width is okay for the rim.

on another note, would changing from standard tyre size invalidate warranty claims on the wheels...i heard of early CLS AMG wheels cracking... what du think?

 

[bobbersmill]

on another note, would changing from standard tyre size invalidate warranty claims on the wheels...i heard of early CLS AMG wheels cracking... what du think?

My own personal opinion (not shared by everyone) has and will always be dont give them an excuse so I always keep my cars OEM. Having said that I cannot see how they could refject a claim if the tyre fitted is within the tolerances of the wheel design.