I usually drive my car 4 mph over the speed limit on interstates (the margin of error for most police radar guns). When driving, I usually set the cruise control to 79 mph. Just the other day, while driving, I was using the +/- on the steering wheel to adjust the speed and it stopped allowing me to set it at 79 mph. It would jump from 78 to 80 and vice versa. I turned off the cruise, turned it back on and the same thing. It will set at 75,76,77,78, and then it jumps to 80, 81, etc.

Any ideas?

 

Bump

 

The +/- buttons adjust the cruise control by 2mph, not just one

 

The speed indicated is about 5% optimistic anyway, so you can add 3mph above 60 (68 indicated = 65 actual). This in no way answers your question, but seemed relevant.

I have had mine do the same thing, but it was pretty random and has not done it again.

 

What happens if you drive @ 79mph and then turn on cruise control?

 

My understanding is that the underlying speed is figured in KPH and then converted to MPH. Some speeds going from kilometers to miles cause the skipping.

It's a MINI thing

 

Mine increments by one either way. Has not behaved in any odd fashion. My commute to work goes through two school zones and two speed traps, so I use it religiously.

 

I have an 08 MCS and I can increase or decrease by 1

 

It usually sets at 80 mph, but I believe it has also set at 78 mph.

 

'08 MCa also +1/-1 with a tap on CC button.

And you always subtract about 6% to know the true speed.

 

Mine on occasion does this as well, I've learned just to adjust it as needed. BTW...I'm running 4mph over. Not seeing any funny lights...yet!!

 

Not all speedos are going to be off by the exact same amount. The reason they read optimistic is to cover for possible variance from one car to another. Also, the exact size of your tires will have an effect. Best to calibrate before you try hitting the exact tolerances of law enforcement.