Changing Diff Ratio in a GU RD28t For Better Fuel Consumption

[Shaunous]

Hi All,
I dont do much low speed/high torque 4 wheel driving, in comparison to the highway driving and touring I do. I know its easy to say stick to 90km/h and its a big difference, but I find it hard enough to not sit on 110km/h with everyone else on the highways, let alone the wife who is worse.
I just want to get the rev range down a few dundred.

Its still got standard size tyres on it, and I do plan on fitter bigger tyres, I realise this will give me more top end speed at the same revs, but how much difference, who knows??? I better do some measurements I spose.

There used to be a web based driveline ratio calculater kicking around, does anyone have this.

But anyway, who's changed their diff ratio to gain better top end, or is this commonly done or even possible for the 2.8l.

Cheers,
Shaun...

[nissannewby]

In the little 2.8 I would be sticking with what it has otherwise its gonna be even more gutless. Go to 33's and you will be sweet. The difference between 31's and 35's on my GQ would be close to 500 rpm so going to 33's should net you the couple hundred you want.

[Shaunous]

Cheers Nissannewby,
I'll keep looking into it.

Do you know if the 33's will fit straight on with only a 2inch lift, or do the GU's need more things done to fit them under and steer comfortably. I never really wanted to go that big in tyres, but never really had a reason.

Shaun...

[nissannewby]

Yeah mate 33's will go. I run 33's with a 2" lift on my gu with no dramas at all. The gu's have plenty of room there are blokes who even run 35's with a 2" lift.

[Shaunous]

Cheers mate, in that case I might in try my luck at fitting them under the standard suspension, i'm a firm believer in not replacing something unless its buggered, my tyres are f#@ked from the recent birdsville round trip, but my suspension although standard height, thanx to previous owner is near new. So i'll see how it all goes.

Shaun.