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Topic: gas mileage?

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gas mileage?
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got 2000 xj with 33's and getting about 12 miles to the gallon! hate to loose the 33's but how much better gas mileage will i get going back to the original tire size? still running stock gears , will changing gears help out? or what else can i do to help out?

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2000 xj 6in lift/33's/whinch and more 2 come. also 71 bronco currently in re-hab. got to have the best of both worlds. gf has 2000 tj yeah i get 2 drive that too!!
choppergar
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On my 96xj runnung 33s got around 11mph and power lost going up hills on main roads. My 235s I would always get around 17.4 and 17.7. And that was always figuring off the factory
speedo. Didn't change speed gear. I changied wheels and tires when I had a long run. Didn't want to go through expence and work with gears.
On my 90xj with 31s I.m running right around 16.5 mpg. And wifes wrangler with 31s shes in the 17s

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Gar Pratt
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How are you figuring your milage? As if you have not changed your speedo gear out your gauge cluster is not true any longer since your running 33's.

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89eliminator
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im running 33x10.5s with 4.10s and getting 20mpg highway and around 16 city.

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ChevelleSSLS6
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96 xj- stock 29" tires (235/70-15 or whatever) and 2" lift- 17mpg mixed, best of 22mpg (55mph cruisin in the countryside)

to improve mpg...
make sure your Jeep is up to date on maitenence, plugs/wires/cap/rotor/air pressure, etc.

enlarge hole in air intake box (use a dremel tool, and take the stock hole and run cuts along the side of the box on the 'fender' side of the airbox and up and back to the top of the stock airbox hole)- this gained me 0.5mpg

run crappy passenger car tires- this will reduce rolling resistance, but, just isn't right!cry

electric fans- I've heard 1.5-3mpg gains with these, and fans from 3.8L early-mid 1990s Ford Taurus's work.  See GoJeep's website... http://go.jeep-xj.info/


2.25"-2.5" exhaust- reduced backpressure means the engine can pump out exhaust gases easier, just as the airbox mod enables it to inhale easier, thus using less energy. And energy is gasoline.smile Maybe a high-performance cat and header would help as well. But I'm poor and just did the exhaust.

-- Edited by ChevelleSSLS6 at 22:27, 2007-11-19

-- Edited by ChevelleSSLS6 at 22:30, 2007-11-19

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My Fleet
1996 XJ "Snowball"- 3.5" lift, bunch of little mods.  I hate pegleg rear axles!
1974 AMC Javelin "Jade Grenade"- 360v8, 4sp, green inside and out. Underfunded Project.
2009 Kawsaki Vulan 900 "Rocket III"- Summer DD
threeEs99
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Biggest gain I saw was from cutting weight. Left tool bag at home , take off full size spare , removed carpet (It smelt funny). take off roof rack. When I hit the trails I just put it all on agian ( less carpet) Allows for extra 60+ miles on a tank.

I haven't cut my air box yet, I like free upgrades thanks.......

-- Edited by threeEs99 at 01:09, 2007-11-20

-- Edited by threeEs99 at 01:13, 2007-11-20

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99 sport.
rust bucket, DD, 3 car seats
04 wj (w/3 car seats too)
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Chris99XJ
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Id like to see a picture of where you made the hole bigger on the air box, I think im gonna go out and check this out. Good idea.

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1999  XJ  SPORT,  4.5'' LIFT,  32'' X 11.50''  TIRE'S



" IF  IT  AINT  RUFF  IT  AINT  ME  !  "
ChevelleSSLS6
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Here's what I did with the airbox... too lazy to look for pics at the moment...
I removed the airbox hose and checked for the intake pipe venturi thing that's supposedly in a lot of XJs, but mine didn't have one, so I set the hose aside.

Next I pulled the bottom portion of the air filter box out. On the front you'll notice a hole about the size of a deck of cards. :(

Now here's the fun part. It doesn't take a long time, but if you don't want to bust little cutting wheels, take your time. Probably about 30 minutes.

Get out the dremel tool (or a cutoff wheel) and go someplace well ventilated (garage, or the bathroom is warmer with the exhaust fan on, make sure mom/wife/gf is not home while doing this in the br).

Looking at it from the front extend the hole to the right side of the airbox as far as possible and the airbox tapers toward the rear for fender clearance, and I just tapered the hole, so it's still 3" tall or so, but the hole wraps around the side of the airbox and tapers like a triangle.

I could have extended the hole the other direction, but I felt that it would be riskier since it seems that water and debris could easier get in by the filter and stuff, and the heat right off the exhaust manifold wouldn't help performance much.

...
on another Jeep website a guy stuffed a piece of pipe inside the 'bumpy' part of the intake tube to reduce turbulence caused by the ribs (think cheap bumpy radius exhaust vs pressure or mandrel bend, but on the intake side) and supposedly this helps as well. I might try this.

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My Fleet
1996 XJ "Snowball"- 3.5" lift, bunch of little mods.  I hate pegleg rear axles!
1974 AMC Javelin "Jade Grenade"- 360v8, 4sp, green inside and out. Underfunded Project.
2009 Kawsaki Vulan 900 "Rocket III"- Summer DD
aci4369
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"Get out the dremel tool (or a cutoff wheel) and go someplace well ventilated (garage, or the bathroom is warmer with the exhaust fan on, make sure mom/wife/gf is not home while doing this in the br)."

The best part of that is I can picture some guy sneaking into the Bathroom like it is Drugs or something.

teevee.gif

-- Edited by aci4369 at 22:00, 2007-11-26

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Chris99XJ
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Maybe this weekend if it is nice ill take it apart and look @ it. Sounds easy.

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1999  XJ  SPORT,  4.5'' LIFT,  32'' X 11.50''  TIRE'S



" IF  IT  AINT  RUFF  IT  AINT  ME  !  "
ChevelleSSLS6
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aci4369 wrote:

"Get out the dremel tool (or a cutoff wheel) and go someplace well ventilated (garage, or the bathroom is warmer with the exhaust fan on, make sure mom/wife/gf is not home while doing this in the br)."

The best part of that is I can picture some guy sneaking into the Bathroom like it is Drugs or something.

teevee.gif

-- Edited by aci4369 at 22:00, 2007-11-26



 from my experience, women don't like men working with tools inside the house, unless it's plumbing, painting, and household-related stuff like that.  In the wintertime when I need to hit something with the rattlecan I lay newspaper all over the place in the bathroom and hit the fan to remove fumes, spray, and leave the fan on until paint dries.  Fortunately for me I live in the parents upstairs while I'm attending college.
  I know, it's weird.



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My Fleet
1996 XJ "Snowball"- 3.5" lift, bunch of little mods.  I hate pegleg rear axles!
1974 AMC Javelin "Jade Grenade"- 360v8, 4sp, green inside and out. Underfunded Project.
2009 Kawsaki Vulan 900 "Rocket III"- Summer DD
 
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