redrockin7

Thought I would add my experience and thoughts after getting my 5.13s and 35" BFG KM2 yesterday.

I drive 20-30 miles one way to work most days - depends where my client is, sometimes I get lucky enough to work from the office 8 miles from home. I must say its taking a little adjustment after only 2 days to see the RPM sitting at 2500 at 70MPH on the highway, but it doesn't feel "screaming" to me either.

I've been putting it in cruise around 65-66 - these are 55 zones mostly - sitting at 2300 and its actually a huge improvement over the 3.73s and 32s which would constantly shift, shift, shift, shift on my drive in. I prefer it to sit at 2300-2500 than deal with constant downshifting even on only 5% inclines!

Drove 34 miles one way to a client today and didn't downshift once on the highway.

With that said, where you could milk the 3.73s and 32s running 65mph for 19-20mpg potentially (if you really wanted) - I don't see that happening with 5.13. My MPG is around 16 and it doesn't improve by cruising at 65 on the highway, which normally it would stock. Even so, stock I was always trying to go 70-75 to keep it from shifting (unsuccessfully) and so my average MPG was still only 17 or so anyway...

I like mine and can't see why, with proper fluid changes, etc. they wouldn't last as a normal gear.

Finnster

I am posting these pics I did last summer for people to see a pretty close direct comparison. I think the 5.13's were a good choice for me.

Steel Rain

Here you go!!!!

https://www.jk-forum.com/forums/show...76&postcount=4

This should help you out. 5:13's are a good choice

Brian

goldtr8

This post made my head hurt

I am glad I have a Rubi with 4:10 and I only want to go to 33 inch tires

Cpt. Flapjack

Yeah, I've got the 3.73s and 33s and I wish I had the 4:10s. I think that would be about perfect.

spinlock

That is because you have a 6 speed. 4.10s with a 6 speed is almost equivalent to 5.13 with an auto at highway cruising speeds in OD.

Finnster

My 4.10's are for sale if anyone wants them>

email me
finnster1@mac.com

TieRod

Two questions:

Many on this post mention their '35's or whatever. Are they measuring them on the ground or going by mfg's numbers? Big difference in some cases. I have measured a few tires of other jeep club members; some '35's' are really 33.5"

#2 Is there any modifications in the tranny to change, say the OD ratio? Is anyone going for a shift kit to firm up the shifts?

My Toyo MT 285/75/17's measure 33" at 32 psi and they are new. I have the Rubi auto and expected more sad news with the ridiculous .69 OD ratio. Sure 'nuff, it's gutless or just useless in OD unless going downhill.
At 65 mph (checked with GPS) 1900 rpm- 4th
" 65 " 2800 rpm-3 rd
" 60 " 1750 rpm-4th
" 60 " 2600 rpm-3rd

Now I don't really need to cruise 75 very often but the above numbers are not good; either too high or too low. And yes my mileage has dropped.

Consequentially, looks like I have to dig up another 1.3 BU's (boat units) for 5.13's