Outer Limits 4x4 Board

My mate has just put a set of 265\75\16 coopers on his 3 litre turbo gu patrol, and says now he is getting 15 litres \100km.
He thinks he was getting around 10l\100 with std tyres. (figures are mainly highway 110 kmh)
What do you 3 litre owners think?

Std tyres are only 265/70/16's.....

If he's getting 15L per 100km where he was getting 10 previously something else is up. Air cleaner springs to mind.

One thing that can shag hwy. mileage is going over 100km/h. When (my wife's) was new we took it Toowoomba driving @ 100km/h and got better than 10L per 100km, drove to Rocky driving @ 120-125 km'h and consumption went up to 15L per 100 km.

Just my thoughts.


Regards

Thanks David, you have just confirmed what I suspected, 10l \100 was when it was bog stock, since then he has added all the usual stuff, draws full of recovery gear winch e.t.c..
The tyres are now adding 10% to the gearing so 100 kph on speedo is actually 110 kph.
So he is driving it faster, as well as it being 100 or so kg heavier.
The good experement would be to drive at an indicated 90 kph, and see what happens.
Thanks for your input.

Also trip meter will read low by tyre size increase in %.
So economy wont be as bad.

Bazzle

One thing that can shag hwy. mileage is going over 100km/h. When (my wife's) was new we took it Toowoomba driving @ 100km/h and got better than 10L per 100km, drove to Rocky driving @ 120-125 km'h and consumption went up to 15L per 100 km.
i have the same problem with my 4.2 petrol if im doing 110 - 120 u chew heaps more fuel

I run 285/75/16 coopers and getting 14l/100klm on my 4.2TD with snorkel, K&N filter and 3"mandel exhaust and the wife makes me sit on 110k/p/hr