So after decoking the valves and changing the oil gasket housing.
And stage 1 tune and tweaked with the Access port by cobb..I have the 2nd and 3rd tunes but I want to fix this
I noticed my speedometer is way off...
cruising up I-95 yesterday my big speedo is telling me I'm doing 95 and So was everyone else no way!!....So my question is how do I reset the speedo or recalibrate it..Wheels 16x8..Anyone?

 

Have you used outside references to establish your actual speed in comparison to the indicated? Just going by what other people are doing won't get you anywhere. They probably don't know what they're doing anyway. Gotta do that first. Unless you've changes wheel size along with everything else that shouldn't be much of an issue. There's a reference table for different tire sizes vs. speed variation on the interweb.
When you establish a benchmark just remember that there is a built in speed difference of 2 to 4 MPH from the factory.

 

How fast do you think you were going? Any chance that it somehow slipped into KPH and you were only doing 59 mph? Probably not but just a thought.

 

Get a GPS app on your phone and confirm. Like stated above, the speedo is normally a bit optimistic compared to GPS.

Mike

 

ok...GPS on my phone it is...Quite a few Blue Hairs here in Florida so I really doubt they were all going 95...I will check with the GPS...

 

Just made a run with the GPS Speedo on my IPhone and I'm about 5-7 mph off which is not bad....Blue Hairs a really driving faster down here...South Florida retiree's...have rocks in there shoes

 

If they're anything like my father was, they're either pushing the gas pedal or pushing the brake pedal. There is no in between.

 

Our 07 reads pretty high as well. It's probably made worse with the 16 inch winter wheels installed as they have a smaller diameter. My wife gave me crap the other day as she was following me in her mini and had to "Speed Excessively" to keep up. There's no doubt that we are at least off by 8mph or so.

 

Even with stock sized tires, my 2011 MCS's speedometer was a bit "optimistic" in it's numbers. I have read that up to an 8% difference is allowed by federal law. So, at 100 indicated, you could be doing 108, or 92. I have a Garmin GPS, and it seems to read ground speed very accurately. My question earlier (on another post) was what does this "difference" between indicated and actual speed mean for my odometer. I would assume that if I am reading 8% higher speed than I am actually traveling, that the odometer would also be off by 8%. So, at 100k actual miles, my odometer would read 108k. I was told that this was not the case. I still fail to see how THAT is possible, but no worries. If that could be explained to me, though, I sure would appreciate it!

Motoring On!