Outer Limits 4x4 Board

hi there i have a question i have nh 3litre manual and 31" tyres and if any one can help it revs about 3000 at 100 klm an hours is there any way to lower the revs to get better fuel economy or do i have to deal with. and i have been told to put 33"inch tryes on it to lower the revs.
i have raised it 2"inches already please help.

they are the same for me

Matt

There are 2 ways to lower revs:

a) get bigger tyres

b) get taller gears

Both will cause your speedo to be inaccurate.

Also, the idea of lowering revs to save fuel is a bit of a misconception. Quite often you'll find that the engine is labouring more with taller gears and as a result fuel economy will actually get worse. Be careful on this....there's a reason why cars are geared the way they are

i have a NH auto i sit on 100kph and am doing roughly 2500rpm at 3000rpm im doing about roughly 120kph and i have 31'' tyres as well....but when im with me mates in there NH's the speeds differ from each 4wd from 5 to 10 kph... i was with another 4x4 with a gps and my speed reading was the same as his gps speed reading and his speed was out by 10kph to the gps......
Gav

PajeroSRV wrote:There are 2 ways to lower revs:

a) get bigger tyres

b) get taller gears

Both will cause your speedo to be inaccurate.

Also, the idea of lowering revs to save fuel is a bit of a misconception. Quite often you'll find that the engine is labouring more with taller gears and as a result fuel economy will actually get worse. Be careful on this....there's a reason why cars are geared the way they are

He's nailed it.

I've got taller tyres, and a replacement speedo drive gear has the speedo accurate within 1% at 100km/h - against a borrowed GPS.

Definitely knocks the wind out of it pulling up hills, I sometimes have to drop back to 4th on the highway. Worst case, I let speed drop as I climb a hill.

On a good run, economy can return high 11's/100km, on a bad run it's bad.

Cheers,

Scott

thank you for the advice so the changing tyres is a good place to start is it possible to change the fifth gearing to lower the revs on the high way or any other mods i am pulling gearbox out to do the clutch does anyone know of a good clutch to put in it.

Somewhere along the line Frank recommended a Daikin clutch kit. When I had mine replaced I told the mechanic I wanted a Daikin kit, and he said he wouldn't fit anything else.

Works good so far.

Cheers,

Scott

Any phone numbers of a good supplier nothing like that out here.
cheers mick