bigger tyres and fuel consumtion

[nathanrhodes90]

Ok just another quick question to help me with my planning my near future mods.

will there be a big difference in fuel consumtion between 31" and 33" tyres on an xj???

[Easy Rollins 1]

Many moons ago a friend purchased a 4rUNNER.hE MODIFIED IT OVER THE TIME HE OWNED IT BUT ADDING SUSPENSION,TYRES ETC.hE SAID FOR EVERY INCH HE RAISED IT HE LOST 2MPG.

Sorry for the caps...

He ended up with 3" lift and 33" tyres.

HTH a little.YMMV

ps.I don't think the wider tyres(12"") helped much either-more air resistance etc.

[SeaComms]

The biggest difference is in the gearing. 31 to 33in tires will drop your rpm's by around 200 to 300. Main difference will be a decrease in acceleration power, which means when cruising on nice flat ground at not to high a speed (say 80km/hr) you will notice better fuel economy.

But as your speed increases, so does your wind resistance and the higher over all ratio will have less power in top gear to over come the wind. You will also notice less power on initial take off, especially if towing. In the JK (shaped like a brick) at 100km/hr and over I get the same or even better fuel economy in 5th gear compared to 6th. This is because they put too tall gearing in the diffs as stock to try and improve fuel economy tests (which are done at 80km/hr...). Same end result as putting larger tyres on!