I own a 2000 CL500 -

The other night I engaged in a little race with a corvette (not Z06) on a straight line of freeway on the way home. Me and him were pretty even, then, at 115mph, my car starts bogging down like it was governed at that speed?? I thought my car was governed @ 130MPH, so I was like WTF?? Anyways, I took it to my local MB shop & everything mechanically/electronically check out okay, but shop foreman informed me that the probable cause for the governor engaging at a lower speed is the larger diameter wheels I have on my car (20"). Has anybody else experienced this problem with 20" wheels on their car??? It's not like I plan on going over 115mph all the time, but when the governor kicks in 15mph less than its suppose to, a little frustrating & makes me wonder whats going on.

 

The speedo should read slower than the actual speed if the ECU wasn't adjusted for a larger tire diameter, if indeed the tires are taller. Nevertheless, the speed limiter should kick in at whatever speed it's set at regardless of the tire size. If the limiter is set at 130 mph, using a 20" tire size shouldn't lower it to 115 mph, even though your car is actually going faster.

 

It's kind of weird, because the governor should kick in at 130 period. Im just looking for another explanation due to the fact that MB is saying everything is okay. I have a feeling that even if my car had stock wheels, the governor would still remain the same because of something else - possibly my ECU.

 

That's what I said (It's not the tires, it's the mph). At least I tried to say that.

Who told you the limiter is set at 130 mph? Seems kinda low. That Corvette is set at 170-something mph.

Did you buy the car new? Could someone else have had the limiter changed?

 

Sometimes people tweak with them things all the time to mostly remove them. Usually they just end up messing something up causeing the governor to set at a lower speed or act irractic. If you didn't buy the car brand new, that's a possibility.

 

i have a CL500 with 20's i get to 135 all the time.