effects on incorrect speedo calibration

[stigmundfreud]

Out of interest if you have a 3.46 diff but your speedo thinks you have a 3.73 diff what would the difference to MPH be, actual mileage and then fuel economy?

My understanding would be the speedo would read under the speed you are actually doing, fuel economy would look worse and that the trip distances would also under read?

[BO55 VXR]

Yes, your speedo would read slower.... not good with the proliferation of speed cameras

[stigmundfreud]

that was my thinking too!

[crisisjez]

If you want to see exactly what the difference is plug the two F.D ratio`s into gearcalc.

It accurately predicted my 5th gear VMAX.

[stigmundfreud]

cheers

I can physically see the difference as before 2000 rpm in 4th was 40mph read out now its more like 45mph

so a quick example to me would be

6000rpm in 4th was 120 now 135

that would account for my questions recently about the speed VBH was getting out of the VXR8 in 4th