Sportrider is right. Rotating mass is more. No matter what gears you run your engine needs to work that much harder to get the weight to spin. I just did 4.56s and 35s on an auto trans (94 whatever that is) and although it doesnt need to downshift anymore going up hills, you can tell there is more weight there. Also depends on the 33s your gonna run.

 

92 auto with 4.10's, 33x12.5's and correct speedo gear here. I'm getting 14.5ish MPG driving back and forth to work every day, 12 miles each way, 50/50 highway and side streets. I'm going 4.56s once I get all the rest of the projects completed.

The only reason it's got 4.10's now is because I bought the axles used and they were already geared. 4.10's just don't cut it, but it's slightly better than my 3.55 and 31x10.5's I had before so I'm OK with it for now.

I also have bored throttle body, 99 intake, neon 4-hole injectors, higher pressure regulator, APN header and 2.5" exhaust with Magnaflow muffler and dual electric fans replacing the fan clutch.

 

I have an old renix 4L and a five speed with 410 gears and 35s. I get in the 20s on the freeway. Only engine mods are new injectors and new exhaust. Nothin major. Cruzing 55-60mph around 2000you rpm. If i go faster than that it eats up fuel. What speeds are you guys traveling on your roads. Wa state is pretty slow. We have 70mpha zones here and there.

 

What if I was too keep my 32s? then what gearing would be best?

 

I know I go way too fast and when I can control myself and go 55 instead of 75MPH I do get noticeably better mileage, but still barely over 15. I'm usually 2800rpm at 75MPH or so. I've changed the speedo gear and it agrees with my GPS so my speeds, distance and MPGs are pretty accurate.

I've got a 400 miles each way trip coming up and the thought of how much that's going to cost in gas is painful, but not painful enough to make the drive an hour and a half longer by driving 55.

Then I had 31s and the stock 3.07s I would get 20ish, but it was a dog on the highway. Since then, more lift, heavier bumpers, etc, have taken the MPG toll.

 

I didnt even think of the constant extras. My rigs pretty light. Just a lift and tires currently. I be in for some crunch when i add that weight my self then.

 

I am going with 4.56's and currently have 32's, but am going to 34's, and mine doesn't get driven more than a weekend a month

 

Manual or auto?

 

3.55 with a ax15 manual is identical to auto aw4 with 4.88 every gear 1-2-3-4 is with in .10 of the other plus with a manual you have 5th for the highway when y need it, I have 3.55 with a ax15 and 4.0 and it’s got more torque then a auto with 4.56

 

I don't know where your getting those numbers from but that's not the case. An auto with 4.56 gears is quite a bit lower than a AX15 with 3.55 gears.

 

I know with a cummins pickup transmission ratio auto vs manual are nearly identical on paper aswell as tach readings.
I'd assume similar on the jeep. But I haven't cared to research it because I honestly dont care.

Drive lots of street dont go offroad =410
Go ofroad some. less streat 456
More off road 488.


Decide to let misinformation on the internet guide you =price less

I doubt many jeep owners track mpg close enough to gather actual numbers worth much of anything. Almost every thing we do will make mpg get worse and damn near nothing will make it better
even regeard its taller heavier with more resistance going down the rd.

 

Yeah, what 00t44e said - that's not correct. Both AW4s and AX15s have overdrives (what you're referring to as fifth) and the AW4s overdrive is taller than the AX15s. The only way your 3.55-ax15 combo has more torque than a 4.56-aw4 combo would be if your engine literally produced more torque than a standard 4.0 or if the one with 4.56 gears and an AW4 had, I don't know, 54" tires or larger and you only had 27s.

AW4s and AX15s are very complementary.

http://www.novak-adapt.com/knowledge...ns/manual/ax15

http://www.novak-adapt.com/knowledge/aw4

http://86.43.94.97/moodlecp9a/mod/re...iew.php?id=346

 

I came here to blast you for spreading misinformation, but then went to GrimmJeeper's calculator and plugged the numbers in. You're not as wrong as I thought.

They are far from the same in every gear, that part is not true. However, in 1st gear, the final drive ratio of those two combinations are 13.66 (AW4 with 4.88's) and 13.60 (AX-15 with 3.55's), using a 1:1 transfer case ratio. I'm very surprised to see that.

Now, as you go up in gears the ratios do not increase proportionally. The final drive ratios in the highest gears are 3.66 (AW4 with 4.88's in 4th gear) and 2.80 (AX-15 with 3.55's in 5th gear).

So it is true the AX-15 is geared lower, and also it covers a larger range of ratios than the AW4. What this doesn't take into account is the ability for the AW4 to operate with the torque converter unlocked. Its not an apples to apples comparison.

 

Yes due to fluid coupling producing lots of heat the auto likes lower gear to help it manage heat better in first and second in offroad slow driving situations.
Atleast thats how i view it wich may not be entirely the case

 

Auto, 4:56, 33's. Feels about the same as stock.

I mainly off road and thought about going lower but the issue is once you go above 4:56 the teeth contact becomes rather small. I did not want to risk braking a tooth on the trail. My D30 is not HP BTW.