Problem with Cruise Control
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Joined: Jun 2006
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Problem with Cruise Control
I'm not sure when this actually started, but for some reason I can't set my cruise control above 75 mph 
I know I used to be able to set it to 80 or when I took it on th interstate, but now it won't set. If I try to set it to anything above 75, the cruise control won't activate.
Anyone else have this problem before, or know what may be the issue?
I know I used to be able to set it to 80 or when I took it on th interstate, but now it won't set. If I try to set it to anything above 75, the cruise control won't activate.
Anyone else have this problem before, or know what may be the issue?
MBWorld Fanatic!
Joined: Apr 2005
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From: SCV SoCal
2002 CLK430
ESP, ASR, ABS, and cruise control all use the wheel sensors to see how fast each wheel is rotating. When there's a large enough difference, and the car is not turning, the ESP is programmed to log that as a error and to shut the cruise down. If the rolling diameter of all four tires is far enough off, that will do it. What sized tires do you have? Also, a tire that's very low on air can cause the same problem.
Thread Starter
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Thanks for the help Marcus.
I have 225/40/18 in the front, and 275/35/18 in the rear. It didn't always do this. Do you think the differences is sizes would make the difference? Why 75 mph? Is that the standard cut-off?
I have 225/40/18 in the front, and 275/35/18 in the rear. It didn't always do this. Do you think the differences is sizes would make the difference? Why 75 mph? Is that the standard cut-off?
MBWorld Fanatic!
Joined: Apr 2005
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From: SCV SoCal
2002 CLK430
Using a Dunlop Z1, that might be a problem. On a Z1, a 225/40-18 revs 831/mile. A 275/35-18 revs 811/mile.
75 MPH isn't a special speed. With matching diameters, you can set the cruise to any speed above 25 MPH (that's per the owners manual, I've never tried above 100). However, the faster you go, the less tolerant of differences in diameter ESP is. If there's a curve in the road, that will make the inner and outer tires read differently too.
Thread Starter
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I just looked up my tires revs/miles:
Goodyear Eagel F1 All Season
225/40/18= 833 revs/mile 275/35/18= 818 revs/mile
Hmm....significant enough?
Can this be problematic? Is there anything destructive I can do by having this difference and in sizes?
Goodyear Eagel F1 All Season
225/40/18= 833 revs/mile 275/35/18= 818 revs/mile
Hmm....significant enough?
Can this be problematic? Is there anything destructive I can do by having this difference and in sizes?
Super Member
Joined: Feb 2008
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From: Bay Area
02 clk 55, 13 GL 450
Only time I would worry bout damage from different tire size, would be a left to right difference. This would only show up in the rear in the form of working the spider gears in the diff. You would burn the clutches in a limited slip application. I'm with Marcus in that for your set up, I don't see anything more than inconvenience than damage.
