Contour Enthusiasts Group Archives Forums General General 109 mph gov on 95 SE

I was under the assumption that when you change your overall tire diameter, it throws off your speedo. I was also under the assumption that cutoff got it's info from the engine rpm. Therefore, it would say 109, but rpms would still be correct for cut off. It sounds a little silly to me for the cutoff to get it's info from the VSS, but ok.

In order for the speed limiter cutoff (as opposed to the redline/engine over-rev cutoff) to work off the engine speed, the computer must know what gear you are in. It would also need to know the gear ratios and the final drive ratio. In the case of the 5-speed manual transmission, that would require switches or sensors to tell the computer what gear the transmission is in, which is a lot of additional complexity and cost for NO benefit when there's a perfectly good VSS to use for speed information, which is already wired to the computer. [1]

In the case of the computer-controlled automatic transmission, the computer always knows what gear it's in, but the VSS is still used for the cutoff.

[1] The VSS is used by the computer to provide a dashpot function where it sets the rate at which the idle air valve closes when the throttle is closed, to prevent "lift throttle snatch".


If the cutoff did get it's information from engine speed, tire size would not change the relationship between speedometer displayed vehicle speed and engine speed. Only a gear ratio change or final drive ratio change will do that.

If you were in 4th gear you might've hit the rev limiter, and not the speed limiter

interesting, ok thanx for the knowledge. I'm alway up for learning something.

My speedo is about 3 MPH off...cuts off at 115.

Well I do have a 5 speed so it wasn't an atx rev limiter, and I was late for work at the time going down I-95 south towards old saybrook (all in CT) and I was watchin for the rev limiter every sec and I just so happen to look at my speedo as it hit 109 and the computer cut the throttle. so I figuered I'd ask to see if anyone elses does that since I read on this site that the limiter goes to 112... not much of a difference I was just wondering. I found the limiter on my dad's 5 speed '01 V6 sebring, and that one is set at 130... that was on Route 2 east toward Norwich CT if anyone wanted to know.

with all that specific info I guess 5-O will be waiting for you next time on that route

i love not having a limiter...

It was only that one time... ussually the cops are all over those highways if anyone lives in CT they know what I'm talkin about.