speedo Q

[ScottHmk4]

going from steel wheels to 17" is gonna have an effect on the speedo im sure, it will have been calibrated with smaller wheels to calculate speed, can speedos be re-calibrated to suit bigger wheels?

 

[ross p]

yes with a large sum of money

 

[QuietQuackers]

Feel free to shoot me down if I'm wrong here, but all speedos tend to overestimate the speed of the car (as anyone with sat nav will tell you!). So by sticking 17 inch wheels on, any difference is likely to change the speedo so that it gives a reading of the 'real' speed of the car i.e. something similar to what a sat nav would say you're doing.

I suppose just to see how big the difference is you could always borrow a sat nav off someone to see how the speedo reading differs from the real speed as measured/ displayed on the sat nav.

 

[ross p]

yeah a speedos usually out anyway not sure by how much though

i have 17s on mine and when it is showing 70 on the speedo, the sat nav is showing roundabout 65-68 mph mark

 

[ScottHmk4]

i got my own sat nav.....mite just do that, how accurate is sat nav?

 

[PaulieB]

i got my own sat nav.....mite just do that, how accurate is sat nav?

on a flat - accurate, on a hill - not accurate

 

[ScottHmk4]

well just back from a wee run, turns out sat nav was getting pretty close readings to speedo, if anything its like 1-2 mph out.....went pst one of them flashing speed signs and it flashed about 1mph out of what i was doin. dont think i have any worries

 

[danmay]

ain't got mine done to be honest, left it as it is!