Thread: Defer Speedo Too Hi

The last 3 LR's - Rangie & Disco I've had did this. Never knew it till GPS

Don't know about here, but in the UK speedos are allowed a margin of error to read high, but mustn't read low. Hence, most manufacturers read slightly high. Noticed it on pretty much every car I've had a GPS in....though the D3 is notably more accurate than the Defender, which reads 5k over same as yours!

but how accurate is a gps for speed could it not be possible that the gps is reading slightly high

My 95 Disco reads the same 5K's faster than I'm actually going. All speedos vary to some degree, then you have smaller tyres, bigger wheels and under inflated tyres all these will affect you speedo reading as well. if it's running 5Ks under don't worry about it as that 5 Ks could save you you a big fine.

Yep, I've always suspected my Defender was 5-7kph high. It's not enough that they are just plain slow, but the manufacturer seems compelled to rub it in.

Originally Posted by dullbird

but how accurate is a gps for speed could it not be possible that the gps is reading slightly high

NO, the GPS will be so accurate you can argue against radar fines!

If it really annoys you Jaycar have a speedo corrector kit that is fairly straight forward to build,if you can use a soldering iron, cost approx $50. I changed the tyres on my series 1 Disco to 215x85 and the speedo is spot on, Problem is now I don't get as good fuel consumption, instead of getting 850k's to a tank now I get 800k's jees I think I'm Irish.

I fixed mine by going to 255/85 tyres.

It's now spot on. Trouble is everyone else drives more slowly now.