gas mileage with lift/tires/axles/gear ratio?

[cal]

well it definately sounds like I have a pretty serious problem going on here guys because I am getting about 5-8 mpg city and 12 highway if I am lucky! I need to fix those damn O2 Sensors. Checked my exhaust and no cracks or leaks that I can hear or see. Would an over sized throttle body and cone filter intake possibly cause something like this? Something to do with the mass air flow sensor maybe? I have been told that it can have the same symptoms as an exhaust leak.

Having 33's and stock gears can cause something like this. :/

You need to regear. We don't do it because it's fun and we have too much cash...

 

[GSequoia]

We don't do it because it's fun and we have too much cash...

Well I don't know about you but I did it for the chicks!

 

[cal]

Well I don't know about you but I did it for the chicks!

aaand you failed.

 

[GSequoia]

aaand you failed.

I don't need chicks anymore, I'm married!

 

[boostamante]

I don't need chicks anymore, I'm married!

I call B.S on that one... I think you need them more now than ever.:laugh:

 

[jeeperjohn]

I don't need chicks anymore, I'm married!

Ahh yes, the end of freedom as we men know it. You know why divorce is so expensive?







Cuz it's damn well worth it!

 

[Rutanisgod]

ive been thinking about re gearing to 4.56s. got a 2000 auto 8 inch lift 33s getting about 12 mpg. went to a mechanic to get his opinon on re gearing lower and they were saying i would most likely get worse mileage due to the lower gearing. so now im kinda stuck in the middle of which way to go. the jeep is a daily driver some offroad here and there. Just looking for opinions from you guys that have already re geared with bigger tires. thanks

 

[GSequoia]

ive been thinking about re gearing to 4.56s. got a 2000 auto 8 inch lift 33s getting about 12 mpg. went to a mechanic to get his opinon on re gearing lower and they were saying i would most likely get worse mileage due to the lower gearing. so now im kinda stuck in the middle of which way to go. the jeep is a daily driver some offroad here and there. Just looking for opinions from you guys that have already re geared with bigger tires. thanks

Your mechanics aren't smart.

The lower gearing will bring your engine back into operating within it's powerband. The only thing I'd say is that with 8" of lift you might want .88's, that's moving a lot of air.

PS - Why that much lift with just 33s? Seems a bit excessive and annoying, I'm happy at 6" with my 35s.

 

[HeepSpeed]

5.5 inches, 10.5 tires, stock axles, 4.56 gears = 20mpg out to Goatfest this weekend on the highway cruising 65-70mph.

 

[codyyy]

HeepSpeed, are you running auto or manual in that Jeep? And I'm assuming 31 10.50s or 33x10.50s? I'd love to get 20 mpg out of my Jeep again.

 

[HeepSpeed]

manual. 33x10.5x15. It's the 4.56 gearing that does it though.

 

[codyyy]

I'm wondering if I can get close to that with an auto and 32x11.50s. I've been thinking of swapping in a manual trans once my auto goes out, but not sure if I'll do that. The main reason why I'd do that is for the extra gear.

 

[cal]

I'm wondering if I can get close to that with an auto and 32x11.50s. I've been thinking of swapping in a manual trans once my auto goes out, but not sure if I'll do that. The main reason why I'd do that is for the extra gear.

Years ago I had a black 87 with 32's and 4.56 gears. I could get 22 mpg if I drove nice.

 

[HeepSpeed]

it's all about driving nice to get mpgs....the lakebed and whoops killed it to 16mpg though

not complaining, my auto on stock tires gets 14mpg around town, but on freeway, I stick to 65-70 and get about 20mpg as well...just be nice!

 

[GSequoia]

just be nice!

There is, however, a point that it no longer works.

I'm a very easy driver and not on the thottle at all times. With mixed driving (to/from work) with top speed of 70 max I average about 14-15.

6", 35s, 4.88s.

 

[codyyy]

Another thing that might kill it for me is the hills, I'm not on flat ground a lot of the time. Either way I'd need that kind of gearing, I can feel the power loss a lot from going up hills.

 

[Brendan_91XJ]

I got a question, how many people that have regeared with a larger tire also changed out their speedo gears?
I did this to mine and am only off maybe 2% vs the gps

 

[HeepSpeed]

my Advance Adapters kit recommended a 36 tooth. I did it and have been very happy. It's essential to watch if you don't have a tachometer. I now have both gauges working great and it's not weird to be "going 90mph" on the freeway everywhere ha-ha

 

[toyotawrench]

Stock hight stock gears (not sure what they are) 31x10.5xr15 procomp steelies, at 65mph i am turniing about 2600rpm, and im getting 14 city/stop go traffic, not sure about freeway milage yet. Hope this helps

 

[GSequoia]

I got a question, how many people that have regeared with a larger tire also changed out their speedo gears?
I did this to mine and am only off maybe 2% vs the gps

I swapped out my speedometer gear when I did my build. The speedometer is accurate within 1% - 2% based on three GPSs (iPhone, my Magellan Maridian, and my new DeLorme USB GPS) and those little "HEy, slow down!" signs.