Jimny gear ratios

[Rjmaas512]

Friend of mine as a Jimny for his other half. She only uses it on road so to get some more MPG out of it they want to change the gear ratios for better road use.

At 50mph the Jimny is at 3000rpm in 5th gear. My SJ is 2500rpm at 50mph in 5th gear. So could you fit a 5 speed SJ gear ratio to the Jimny or something like that.

Any information would be great.

[twiss]

What size tyres are on it? If they're 195s you could up the overall ratio by putting the slightly larger 215 tyres on it...

Might not make a huuuuuge amount of difference but if you have any 215 tyres to try it out with, its worth a crack!

[Rjmaas512]

Well after some calculations the 215 tires would increase MPG by 3%.

Changing the diff's to auto diff's would increase it by 5%

Vitara gear box ratios lower the mpg

Wondering if Vitara axels would fit a Jimny, or whether an SJ gear box would fit. Now about do the calculations for the SJ gearbox.

[ScottieJ]

I'm not sure if I've ever heard of anyone swapping an sj gearbox into a jimny, its common to swap the transfer boxes from an sj into a jimny to lower the gearing, but that would be no good for your mpg.

Vitaras are Independant front suspension and the rear axles have a centre diff, so you would need to fit a front samurai axle, at which point you might as well just use a samurai rear axle as well for the offset diff. That is a lot of work to just get better mpg though.

Samurais do have a slightly higher ratio 5th at .79 not .86 like the jimny. The gearbox will bolt straight upto a jimny engine as they all share the same G13 block, the mounts will probably be different though? I'm not familiar with jimnys though do they run a mated or divorced transferbox? If they run a mated transfer box I.e the transfer box is bolted directly to the gearbox not connected via a prop like the sj then you might need to fit the sj transferbox as well??

All in all I think its going to be a lot of work for minimal gain.

Id say the jimny auto diff are your best option

[ScottieJ]

What year is your jimny? Just found out From 2005 onwards the transferboxes have 1:1 in high ratio instead of 1.3:1

Have a look here for all the info http://www.bigjimny.com/images/document ... ratios.pdf" onclick="window.open(this.href);return false;

[Rjmaas512]

Thanks for the info.

Will see what we can do. Currently looking on fleebay for a transfer box or two and have a play.

[Rjmaas512]

What year is your jimny? Just found out From 2005 onwards the transferboxes have 1:1 in high ratio instead of 1.3:1

Have a look here for all the info http://www.bigjimny.com/images/document ... ratios.pdf" onclick="window.open(this.href);return false;

Well we've come up with a plan Fit a 2005+ Transfer box into a 2000 jimny.

Was wondering if anyone knew if a 2005 Transfer box can be used in a 2000 jimny and whether the electronics can be removed to allow manual change.