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Unread 03-20-2010, 11:43 PM   #31
lateralus3
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here drive this for good gas milage

peel-p50.jpg  
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Unread 03-21-2010, 09:06 AM   #32
Eshindi
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^^ x2

I bought a 2dr Geo Tracker for a DD
It gets about 30 MPG around town and to and from work.
Cost me about 2,200 10 months ago and probably saved me half of that in gas so far by not driving my jeep with 14-16mpg.
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Unread 03-21-2010, 09:46 AM   #33
QuadraTokn
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Do they make 2.35 gears for Jeeps? That would go well with 22" tires, and you dont have to drive any gay *** cars!
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Unread 03-21-2010, 10:09 AM   #34
comptiger5000
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The tallest gears I know of for the D44a (these also exist for D30/D35, although those might go taller) are 3.08. Those, in a V8, with mods to enhance low-end torque, and stock size, or slightly smaller, tires, should give decent city mpg, and pretty good highway mpg.
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Unread 03-21-2010, 11:21 AM   #35
sdowney717
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You can do something similar with taller tires.
I tried this in a Saturn SL2, BUT I found out it loads the engine down too much.

Net was
lower RPM at highway speeds and same exact MPG
more load on engine so acceleration was slower.
I ended up putting the taller tires on the rear and the standard size back on the front.

It was nice to get the Saturn up a little higher in the front, It always wanted to run the plastic bumper into those cement curbs in parking lots. Taller tires cleared that cement stop.
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Unread 03-21-2010, 07:05 PM   #36
bensonr
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I'm running on Firestone Destination LE P245/70R16 with 35psi. My speedometer reads 1.5 mph slow when I'm going 60, so I would like to go with a taller skinnier tire.
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Unread 03-21-2010, 07:14 PM   #37
comptiger5000
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Taller will make the speedo read even lower. That size is pretty good for a stock ZJ or WJ, so I wouldn't worry much about it.
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Unread 03-21-2010, 08:29 PM   #38
BlackDaddyZJ
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Quote:
Originally Posted by Mike97ZJ View Post
That's actually really good mileage.



And FYI, I only get about 14.5 with my I6 ZJ.
my last tank of gas i got 16mpg with the 5.2 about half highway half city miles and i was takin in pretty easy
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Unread 04-02-2010, 03:00 PM   #39
bensonr
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Quote:
Originally Posted by comptiger5000 View Post
Taller will make the speedo read even lower. That size is pretty good for a stock ZJ or WJ, so I wouldn't worry much about it.
A taller tire will make the vehicle go faster than a shorter tire at the same speedometer reading. So a taller tire will correct my 1.5 mph error.
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Unread 04-02-2010, 04:31 PM   #40
reconvet88
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cold air intake, with large diameter tubing (if you do this, watch out for water!)

smaller tires or higher PSI.

bore out your throttle body, or clean it up, or both.

get an adjustable fuel pressure regulator.

fuel system cleanup (from a mechanic, dont just get the additives)

KEEP your fuel system clean by using sea foam every fill up, or lucas fuel cleaners. lucas is highly recommended by my mechanic.

not sure on this one but i believe new spark plugs will help a bit, get platinum 4's im working on getting those now.

lighten up the jeep! if looks are not an issue with you, take all kinds of useless stuff out of it that adds weight.

theres all kinds of things you can do, most of them are cheap.
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Unread 04-02-2010, 07:49 PM   #41
Merc1973
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Quote:
Originally Posted by ShootgunSchmid View Post
16-20MPG, is a good number for a WJ. I drive about 3,000 miles or so every 6 weeks. So drive alot, things to think on some of the things you list will help in some cases. Also what size wheel/tire combo you are running. It has to do with rolling restances. I avg right at 18-19 mpg with 3" lift and M/T's. Oh yeah i have the 4.0L and 233,xxx or so miles on it. all the main stuff is OE, save the lift and preformance goodies. Before the tire swap i was pulling 20-23 hwy. So it is possible. It all comes done to driving habbits and maintances. Remember its a Jeep, and drive what you want. I know when i came back from Iraq gas was close to $5 for 91 which is what i run in my mustang. I drive what i want and deal with the gas prices. Piss on Hybrids.
This.

I currently commute from western MD to Baltimore daily and i refuse to drive a tiny-death-trap-beater because it gets 40 MPG, just accept your MPGs and enjoy the drive!

Also stay away from CAI and bigger throttle bodies since increased air means the mixture of gas will also increase......
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Unread 04-02-2010, 08:57 PM   #42
EisBlade
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Quote:
Originally Posted by lateralus3 View Post
here drive this for good gas milage
LOL...that looks like the front end of a plane with the wings, tail and propeller chopped off.
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Unread 07-30-2010, 10:40 PM   #43
billzcat1
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I know I'm bringing this post back from the dead, but I picked up quite a bit of mileage (albeit in a ZJ 4.0) through proper maintenance. Do ALL the fluids and replace with synthetic. I run Mobil1 HM oil now too at the factory-recommended 7500 mile drain intervals. The previous dino oil was getting changed every 3000 and was filthy. Before the switch, I ran some lubromoly engine flush and the Mobil is staying pretty clean but is also doing a good job washing out some of the misc sludge you can see in the valve cover.

I also did a full tune up and went with NGK spark plugs. They seem to work better than the Champions I used at the last tune up. Making sure your vacuum system is intact is important - small vacuum leaks cause the engine think it is running lean and adjust fuel to compensate. Making sure the PCV system is unclogged and operating correctly helps. If there is too much crankcase pressure, you will not only be burning oil, but restricting performance. I also Seafoamed the chambers and cleaned the throttle/ISV with throttle body cleaner (better than carb cleaner because it contains a lubricant). This really helped in the low-throttle driveability so I could use less throttle for average acceleration.

If you have more than 90,000 miles, go with a new front O2 sensor. This is the sensor that the ECU uses to adjust the mixture. They have a lifespan of about 100k.

The only mod I did and also the biggest help in getting more mileage (and also more response off the line/on the trail) was deleting the mechanical fan and installing an electric fan. I'm not sure if your WJ has the hydraulic-powered fan or not, but if it is mechanical, ditch the fan and clutch and go electric. If you are moving more than 20mph you don't need to be spinning that big heavy apparatus. I run a Ford Taurus 2-speed fan with the DC Control 2-speed controller. Even sitting parked or crawling at 1mph the fan only runs about 30% of the time and doesn't even use high speed, even when it was 100F. With this I'm getting 17 mixed 22 freeway mpg in the boxy ZJ with 200k miles on it. The motor runs so smooth and quiet without it and I would highly recommend this to anyone with a Jeep. There's no downside!
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Unread 07-31-2010, 07:35 PM   #44
xJoshxx
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+4's do nothing waste of money the spark will always take path of least resistance.
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Unread 07-31-2010, 10:06 PM   #45
billzcat1
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Yes. Also in some motors, the flame propagates differently with the +4s and that's not necessarily a good thing. The 4.0 was intended to have a single prong electrode and runs just fine with regular copper plugs. The only advantage to +4 plugs (assuming you have no ill effects) would be longevity. The platinum and 4-prong design should be good for around 100,000 miles.
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