Outer Limits 4x4 Board

hey guys
i got a 04 triton 2.8td and i was wondering how much would 31's knock my fuel economy and speedo out. the tyre bloke said that they would knock the speedo out but by how much. also is 13l per 100kms of fuel consuumption sound high. thats keepin every gear change under 3000rpm and not gong faster then 105 andim rollin on the standard cheese cutters at the moment.
cheers
Adrian

I know nothing of your particular engine, but that sounds pretty high to me, I get about 15-17L/100kms in my 3.5L LWB Pajero in city driving. So I would have expected you to get a fair bit better due to A a lighter car and B a more effiecent engine.

yeh i know i thought it sounded a bit high. last time i filled up i went 400 kms and i put 52 litres into the tank
75 litre tank so that works out to about 13 l per 100km. is there any thing i should be getting checked to try and solve the problem.

It would be sending out a bit of black smoke?

With injector pumps it's best to just take them to a specialist. The last Triton our work had was a sport model and had 265/70/16 on it (roughly 31 inch) anyway.