w208 tyre profile cruise control problem

[chrisf-1]

Hi everyone I have owned a 1999 W208 cabriolet CLK pre facelift 320 for the last 5 months (so still lots of bits to do). I have a problem with the cruise control so I had a chat about it with the chap who read my codes for me and he said it is the rear wheel tyre profile the car came to me with aftermarket alloys so I will check exact sizes and post them tomorrow, anyway what happens with the cruise is it engages as it should but between 65-70 mph the cruise on its own disengages while I am accelerating with cruise stalk to set at my required speed. Now I have no reason to distrust this man's word as in fact his code reading with star was much cheaper than I was expecting and everything he said so far has been correct. The car is on 17'' wheels so could someone let me know (a) if 17'' is the correct wheel size? and if not is there a profile tyres that could be put on the rear to correct the problem and. (B) What size wheels and tyres did this come out of the factory with? Many thanks Chris

 

[andy27168]

Hi,
Normally if you have the 17" rims then you will have staggered rims, 7.5" on the front and 8.5" on the rear, correct tyre sizes for these are front: 225/45R17 rear: 245/40R17.
I have a very similar issue with my AMG at the moment, I have the correct tyre sizes on mine, it does not bring up any warning lights and no fault codes, "I think" I have a dodgy reluctor ring on the rear.

 

[sspeed]

As above....
Mercedes offer several different wheel and tyre combos for each model so unless each rear wheel has a different circumference, then I cannot see a 17" wheel causing problems..
Just check that each rear tyre is actually the same size (Im serious)..

your Car was available with several wheel sizes.. 16" / 17" / 18" .. Even 19" in AMG and can you believe 20" in Brabus

Tyre sizes should be:

16" Front AND Rear 225/50 x R16V

17" Front: 225/45 R17 91W Rear: 245/40 R17 91W

18" Front: 225/40 R18 88Y Rear: 255/35 R18 94Y

19" Front" 225/35 R19 88Y Rear: 255/30 R19 91Y