gq wagon 3.9 diff to a 4.11 ratio.

[kbchez]

Has anyone done this with there TB4.2 EFI gone from a 3.9 ratio to a 4.11. or a lower ratio.
Since the amount of fuel they use by going to a lower ratio should improve the fuel comsumption.

With the 3.9 ratio everytime a hill comes into view the GQ seems to slow down heaps and requires heaps of acceleration.
With lower ratio it should fly up the hills and not work as hard and return a better fuel comsumption.

What ratio does the GQ ute have in it.

:biggrin::biggrin::biggrin:

[BigRAWesty]

It's a hard call..
A bloke up near Pt pirie bought some 4.6 diffs for his td42 auto and swapped em out with his 4.1's.
His was a 6 wheeler dual cab and his fuel usage went from high teens to around 12/100..
Sure it increased the rpm by a few hundred on the highway, but the engine was working less..

But a td42 turbo is completely different to a tb42..

It will help with the hills for sure..
But not sure if it'll help overall..

[kbchez]

Thanks Mate,
I have concidered going to the 4.3 diffs. I thought it may increace the revs heaps sound like not really. It may be a better option to the 4.1

[the evil twin]

Thanks Mate,
I have concidered going to the 4.3 diffs. I thought it may increace the revs heaps sound like not really. It may be a better option to the 4.1

If you change the diff ratio by 'x' percent you change the RPM by the same percent for a given speed.
Sooo... if you go from 3.9 to 4.1 that will be 5% which means if you did 2,000 RPM @ 100KPH you will now do 2,100 RPM at 100KPH
3.9 to 4.3 will mean 2,200 RPM after 10% change etc etc

[kbchez]

Hey thats not that much differance. I can live with that much in the RPM range.

I was thinking it would be like around 500RPM. Great news.

Since this old girl has had LPG in it for about 15 years and the cylinder expired and never tested. Its out gone dead.
I have a spare set of injectors which I will service and put in.
Then remove all the LPG stuff.
I will, See how the fuel bill is.

[the evil twin]

Small difference?
Well, Yes and No.
You may be suprised how much a few hundred RPM make.