Hi,


I set up my speedo healer using a sat nav, drove it until the sat nav said 60 and i made a note that the clocks read 108.

I put this into the speedo healer online calculator and it told me i had a error of -44.4%

I put this value into my speedohealer and presented it for SVA.

I failed the Speedo calibration test at SVA by a small margin, the vehicle was traveling at 72mph when the clocks said 70.


An error according to the speedohealer calculator of +2.9% ( based on my initial setting).

My question is.....

Do i add +2.9% to my -44.4% reading to get a new calibration figure of -41.5?

colin go on there website and put the speeds in it tells you how to do it really simply

yes but it either tells you to 'reset' the speedohealer and i would then need a fresh set of readings ie turning up to SVA having not done anything with the speedo healer.

If i reset the unit my readings would be back to the same as before approx 60 reading approx 108 again.

i cant just reprograme the unit with the +2.9 reading or it will be WAY off.

[Edited on 11/8/07 by locoboy]

Working backwards from your SVA figures - 72mph on the SVA rollers would have read 123.67mph with SH reset to 0. If you used a figure of -40% this would give you a speedo reading of 74mph at an SVA measured speed of 72mph. This would be a better bet so you are giving yourself a small margin for error. All production cars over read by a small margin.