Okay so I ran a test in 4th gear as this removes the ambiguity of which gearbox as they are all 1:1 in 4th gear.
I rang a few mates and compared. My car is the last column.
I think if you combine this with the 10% over-stated RPM on the dash... then these are within measurement error and it all...
Good replies guys.
Old.Tony i believe your maths is correct in those examples.
Tonight I measured the circumference with some thin rope and got 2.37 (compared to 2.398m if the tyre was 'exactly' to spec)
As you can see this is not the source of my problem, they are very comparable.
Next...
Thanks guys.
I will measure circumference tonight using a tape measure. Maybe tyre wear has attributed, or the manufacturer of that specific tyre is faily out of spec. Good thinking.
Speedo was spot on compared to GPS.
Any other thoughts on how these calculations are wrong?
Something just...
Hi guys,
Brand new here so I apologise in advance I'm this isn't the right place or this has been discussed.
As the title says: 2006 ZD30 Manual, D22 STR
Tyres: 255/70/16 (slightly smaller than stock)
At 110km/hr my rev's are at 3100 RPM = 51.66 rev/sec
This is ridiculous for a diesel...
The...