Since picking up my '96 VXi 4 years ago, the speedo has been under reading by almost 25%. I had thought this may be down to somebody replacing the final drive with a 3.14 or something like that. However I realised that in 3rd I hit the rev limiter around 150kmph. From tech specs sheets that's 6800 rpm (the needle of the rev counter waggles so wildly when accelerating you can't read it). Doing some maths with 559mm diameter ZZS tyres, and assuming standard ratios in the gearbox, the standard 3.92 final drive would max out at 145kmph. Close enough given wheel diameter changes with speed, pressure, temperature. Further checking at my best estimates of a constant 4000rpm, and GPS speedo readings in 1st, 2nd, 3rd, 4th it would seem to confirm standard final drive. So I assume the gearbox and final drive are standard. BUT the speedo is still under reading by almost 25%. Does anybody have a clue how can that be?