hi guys

car is still restricted which I believe is 118mph bit surprised when it drove faster.

I was getting the speed from a gps, I know that the clock does not read true but how inacurate would you expect the regulator to be?

around 10% out would be fairly normal. Stock Speedometer system is pretty poor quality in the Z, and adding any form of after-market kph>mph converter would only make it worse.

Most car's speedometers over-read to be honest mate; even new and (supposedly) high quality cars....

 

...although the deviation is perhaps not as much as it was in the "old" days! The question is, how far out is your speedo compared to your GPS - altering the wheel/tyre sizes also has an effect too. And how do you know that your car is actually still limited to 180km/h? I would guess that with 1990's technology, the car will never know how fast it is trully travelling but would have to base it on signals received from the speed (and possibly ABS) sensors.

 

Supposedly the UK spec was limited to 155mph - and in What-Car/Autocar tests back in the day, the 300zx TT did achieve a genuine 156mph top end.

 

I also know that on my UK spec car, running on 265/35/18 rear tyres, the speedo is not far from the read-out on my sat nav at most speeds. At 70, the readings are identical; on a track, at 100 there is barely 2-3mph in it - although at varying speeds in between 70-100 it has been as much as 7mph out; but at 120 it's once again very close.... Like I said, on a track and not the public road...

 

Richard:cool3:

with my 19's on, my sat nav always says im doing what my speed o says im doing. does my nut in, as on my old pug, the car was 5mph slower than the GPS. my xantia was 7mph slower than the GPS and my silver zed / black zed and first AH3 zed, were all 5mph out. but the blue one was dead on, and so was the black one, once id changed the wheels over? so i always slow down a bit for speed camera's now

wont say how fast I was going for obvious reasons ,no change on the wheel size but very surprised as I know that the gps is very accurate

thanks all