wheels & Tyres.

[Geoff W]

Hi all.
Just got some original MB alloys for my 97 c180, got them very cheap and they are cleaning up a treat, as new in fact.
My original steel wheels are 15" and are fitted with Mitchelin energy 195/65 R15 tyres, where as the new alloys are 16" fitted with 205/55 R16 Mitchelin pilot tyres.
I have looked at the calculator kindly provided by Bolide and there is only a outer diameter difference of 2mm.
So i have the following questions:
1/ Is a 2mm difference acceptable?
2/ The tyres on the alloys are very good condition with around 4mm of tread left to the wear bars, when i bought them i thought the tyres would be scrap, so is it worth having them balanced to use up the remaining tread, or should i just buy new tyres?
3/ my original tyres have 91H on them whereas the tyres on the alloys have 91W on them, what does this signify?

Due to help from members of the forum i managed to get the new studs from e Bay for £20.00, not bad Eh?
Thanks to everyone and a happy new year to you all.
Regards Geoff.

 

[jberks]

Geoff,
sounds like you have everything you need. The tyres are reduced from 65 to 55 profile already to allow for the larger diameter wheel and the 2mm difference is normal. Taking into account that tyres vary by the tread depth over their lives which is a lot more than 2mm. So, I'd say yes they're fine.

I'd certainly use the tyres but I'd also have them looked at closely first to ensure there isn't any damage, then a balance to ensure all is well. Assuming this is ok, yes I'd run on them.

The 91h/w rating is
91 = load rating 615kgs
h = 130mph
w = 160mph
so unless you intend to sit on athe autobahn flat out for a couple of hours, either are fine!

http://www.tyresave.co.uk/tyrspeed.html

One thought is the bolts. Mine has different length bolts for steel as against alloys - not sure about yours but worth checking.

 

[Blobcat]

2mm should not make a difference, tyre wear can make up for that

I would balance them and fit them, cheaper than new hoops all around

H & W are the speed ratings, W is much higher than H so from a legal point of view you are fine. 91 is the load figure, there was a thread on this recently.

Why not wear out the tyres on the steel wheels whilst the roads are salt covered then put the alloys on in the spring?

 

[Geoff W]

Hi all. Thanks for the speedy replies, Yes i am going to use the steel wheels for the winter, don't want to trash my new wheels, and i have actually bought the correct bolts off e bay yesterday (Details and part Nos as supplied by forum members).
So thanks to you guys, it seems my little venture turned out OK.
Many thanks Geoff.