First of all, I did search! Maybe I just suck at it, dunno.

Anyway, I am running a 97 surf currently on 265/75/16s with 4.11 gears. I have the 3.0 diesel and I think the T/C is the same as the 4runners, 2.29(?) ratio.

So with 315s, what would you recommend, 4.88s or 5.29s? I don't ever plan on running any bigger tire and may in fact run 285s at times. I mostly play in wet heavy snow and it's having a tough time now even in low, in fact I never get out of low!

 

Since most of us are diesel stupid and I don't feel like searching any harder, care sharing your engines specs ? IE torque/ HP.

I'm gonna take a stab and say with a torque powerhouse, you'd only need 4.56 or 4.88's with 35's. Diesels don't like to rev high, so you gotta keep the revs down, meaning you don't need uber low gears.

Personally, I run 5.29's with 33's on my gas 2.7L. With all my armor and extra weight (even in my single cab taco) I still feel like it doesn't make the hills like I want.

 

No prob.. the kz-te engine makes 130hp and something like 250lbf of torque.
It gets it done. That's about it though. No big tire burnouts but since gas is about $6 a gallon here in Japan... well you know.

The tranny gears are different and I turn about 2300 at 60mph with a redline of 4400 or so. Here is more info on the engine if anyone is interested..


The 1KZ-TE is a 3.0 L (2982 cc), 4 cylinders, SOHC, 2 valves per cylinder turbo diesel engine with indirect injection. Bore is 96 mm and stroke is 103 mm, with a compression ratio of 21.2:1. Maximum output is 130 hp (97 kW) @ 3600 rpm with maximum torque of 29.3 kgf·m (287 N·m) @ 2000 rpm. Redline is 4400 rpm. First produced in 1993, it is still used in new model vehicles today. 1KZ-TE also adopt the electronically controlled fuel injection, ETCS-i (Electronic Throttle Control System - intelligent) technology which is similar in basic construction to a modern gasoline injector, although utilizing considerably higher injection pressures, it is an indirect injection engine which gives it a significant efficiency and fuel consumption penalty. It was replaced in most markets with the 1KD-FTV engine which is common-rail direct injection and uses considerably less fuel.
Used in KZJ71W, KZJ78W, KZN160.
The intercooler equipped version of the engine power up to maximum output of 145 hp (108 kW) [Aust. 130hp (96kW)] @ 3600 rpm and maximum torque of 35.0 kgf·m (343 N·m) @ 2000 rpm.
Used in KZJ90 (Prado, Colorado 3-door), KZJ95 (Prado, Colorado 5-door)[1], KZJ185 prado.
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Since these rigs have different tranny gears it is not easy to use any of those online calculators as they are for the gas rigs. I think my top speed with stock tires would be around 100mph, redline limited, whereas I would suppose the 2.7s and 3.4s would be limited by wind resistance. Maybe the 4.88s would be better..

 

Just know that every step you take in gearing will move the rpms up about 250.
So you go from 4.10-4.56, you'll be 250 RPM's higher. from 4.10's - 5.29's I was 750 RPM's higher.

I vote you get the tires first and go from there.. See how it pulls, see how many extra RPM's you'd need to hold a certain speed.
I know that's not much of a help, sorry.

 

try playing with some gear calculators:
http://www.rocky-road.com/calculator.html
http://www.grimmjeeper.com/gears.html

these will allow you to plug in different gear ratios & tire sizes...

 

........

 

crap...night shift sucks, I need to get some sleep....

however the grim jeeper calculator does allow you to independently input your own transmission gears up to a 6 speed.
so as long as you know your transmission gears...gas or diesel is irrelevant with that particular calculator

 

Well true... Don't know if that info is available to him though.
Either way, get some sleep !

 

i think the transfercase gear ratio for low range is 2.56:1 not 2.29:1. for 35" tires, 4.88 might help.. but i'm not sure how your kzn185w is having difficulty with 32" in the snow.