Not sure, but I think he meant that it's wound a little tight on the tach (high rpms).

Jason

 

Is that a bad thing? It's what Dave at northridge4x4 suggested to me

 

Higher RPM's = less MPG, but a little more power.

 

2dr manual trans on 35 Toyo's. D30 front and D44 back. Just went to 5.13's. RPMs are very very close to the chart at the indicated speeds. Gave me back the zip I had when stock. Maybe the RPMs are a little high even in 6th gear......feels like I need to shift one more time when running down the interstate which I don't do very often. Not my DD so I'm very happy with the upgrade. 3.21s were very sluggish.

 

higher rpm's = more hp
more hp = fewer downshifts out of OD
staying in OD = better mpg

Constantly shifting in and out of OD is what kills the mileage, not the extra 100rpm.

 

Does anyone know if the package deal from Northridge it's called Yukon JK jeep gear Front/Rear gear 4.88 or 5.13 and install kit. It doesn't say wither or not its for Dana 30 or 44? has anyone installed or have on their jeep??? i would really like to know Its at a great price oh i'm running stock 4dr wrangler unlimted.

 

Missed the part about the OP having an auto trans . I am so glad I opted for the 6spd. Sounds like the auto is alot harder to find a "sweet" spot.

 

Yep, there is a huge difference in the gearing requirements between manuals and auto's.

Auto, 5.13's, 35's = 2450 rpm @ 70
6spd, 5.13's, 41's = 2473 rpm @ 70

Given the same gearing, a Manual needs tires that are about 6 inches taller to run the same freeway rpm. (just straight rpm, not taking added weight or rolling mass, lift height and drag, whatever else, into consideration). You just can't over-gear an auto JK when you get past 33's.

 

yea i just put 35's on last week on my 2dr with stock 4.10 gears and a d30 upfront d44 back, i have noticed that its a little more sluggish but not unbearable at all, but usually on the highway going about 65 it shifts up to a higher gear and my rpms are at about 1500, so it does take longer to get up to speed

 

sounds like 5.13's are still the overall verdict. thanks everyone! now i just need to save up. and hope that when i do the lift..i dont feel the need for 37's to complete the look