Thread: Tyre size on D1 tdi

Originally Posted by klappers

So how does that work? I have the same tyres and stuff... So which is reading correctly? GPS or Speedo?

Well from what I have read the speedo's generally under read by about 6/7% so if that is correct the likely hood is your gps is reading more correct.... as your speedo would be under reading. However if you have bigger than 235/70/16's on then you lose the percentage within the speedo. I'm not sire what size tyre is more acurate on the speedo you would have to ask.

This is stuff that I have read and not worked out myself so happy to stand corrected

i run 265x70x16 coopers muddies on standard disco 1995 only trouble i have is on full lock it rubs the control arms but thats it
and i sit 5ks under the speed as my gen rule

but been told standard tyre was the 235x70x16

Originally Posted by Stue 3 doors down

I have a D1 pre update disco and it had 225/70/16 when I bought it but this means the speedo is out by about 5-6% so if your speedo says 100kph then you are actually doing 91-95kph roughly with out getting a calculator.
I have 245/70/16 BFG muds and they hit my rear guards when flexing off road and damaged the guards, the speedo is over the 100kph mark by 3kph at present but this will change whne I get new tyres. What I am told 235/70/16 is spot on with the speedo and no guards require modifactions. Keep in mind that the fuel consumption will go up but this is mostly due to your speedo reading.
Hope this helps

aparently it is ...(but with my limited and not expert experiance in these matters )
...mine seems to be 7km/hout ..as in doing 100km/h ts doing 93km/h..so beats me ...

cheers

Originally Posted by klappers

So how does that work? I have the same tyres and stuff... So which is reading correctly? GPS or Speedo?

I HAVE 245X75 COOPERS AND NOW THE SPEEDO READS SPOT ON AND ITS BEEN CHECKED WITH 2 GPS UNITS. PRIOR TO FITTING THE BIGGER TYRES 100 KS ON THE SPEEDO WAS 93-95 ON THE GPS

Work this out, I have gone from 31" to 33" tyres and now my odo is within 1%, but my speedo is only 5% outaccording to GPS.

Good old LR!

JC