Ratios

Got a 1999 Jimny with stock ratios on 31x10.5 mudders. Wondering if i should try my best to find 4.3 diffs or just get a 24% reduction high and low for the t-case. Anyone know the pros and cons of each? (I don't need incredible low gear capabilities, as this is my winter car) And which would give more power? At 90 KM/H (56mph, my legal speed limit), the fifth gear is kinda struggling on FLAT surfaces, good on declines, though 

31s are 18% bigger than standard.
Your diffs are 3.9, so switching to 4.3 will give a 10% reduction which will help but isn't really enough.
When you consider the extra weight of the tyres as well as the size I think a 24% reduction will be about spot on.

Yeah i checked up on that. I believe the difference is right around 15%, though. The car wheels are around 2.'' wider than stock, and heavier tires. The 15% and 24% reductions seems to cost about the same, mostly worried about what it would the revs would be at around 56-62 mph in fifth gear (fifth is 0.864:1 for this gen, not 1:1)

Are the 31's of any practical use to you, and do they outweigh all the negatives?

If the answer is no, then I would suggest you revert to a more realistic wheel and tyre.

Roger

Winters in Iceland are quite a thing to behold, especially the past 2 years. I definitely need them. Should have explained a bit better with ''being worried about rpm''. Obviously the rpm will be high, and fuel consumption will get higher, what im worried about is overdoing it. If i need the 24%, then i need it, and will get it, regardless of rpm and fuel usage. If it's overdoing it, it's overdoing it. That's kind of where i'm at at this point. I'll probably go for the 24%. Seem like i'd be around 3300 rpm driving my legal limit, and that should make the car drive alright

Yes, info. is key to getting the right answer. You will, inevitably, increase wear and tear especially in the hubs and brakes but these are things you will have to expect. Being Iceland, there is a wealth of knowledge on the technology for driving on ice and snow.

Roger

3.9/4.3=0.90 or 90%, so 10% lower gearing. Personally I'd always go for lower gearing over high. A few more revs at cruising speed will make barely any difference to economy but the improvement in driveability at low speeds is massive. Basically you have a choice between 10% more torque or 24% more torque.