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Discussion Starter · #1 ·
Hey all! I have had my jeep (2005 Wrangler Sport, auto) since last September, and have done minor things with it, including just a 2" body lift and 31" tires, as opposed to the stock ones I got with it. I am noticing terrible gas mileage and need some ideas to increase gas mileage that actually work. I know adding exhaust, or K/N air filters, etc...may or may NOT increase it, since the motor might decide to start running rich or lean. Anyone have any ideas and some help>?
 

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what are you getting??

has it been this way the whole time?
since you got bigger tires??
since the lift?
it could just be what a jeep usaully gets
the auto may also be having a problem
what kind of driving have you been doing??
a little more info and we can figure out where your problem is and then fix it
 

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Discussion Starter · #3 ·
Well good questions, I guess I should have answered those in the first place.It was never good to start with, but I think it has decreased since the minor lift job. I definitely noticed after, to more of a degree. I do regular driving day to day in it, thus I did not go with a bigger lift or tires. The auto I am sure has something to do with it. What makes me mad is that the average speed limit is 40 here, and I have to get about 43 - 45 to hit overdrive. Otherwise I am in high 4th a lot of the time, so I try to make it to that point when I can. I doubt my speedometer is off much since the tires are not much bigger than the stock. I try to avoid jackrabbit starts in daily traffic and drive it relaxed.
 

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Pushy, Loudmouthed, and Ballsy
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You still didn't tell what mileage you are actually getting. You have to understand you are driving a box with wheels. Not the most aerodynamic vehicle out there!!! I would suspect your speedo is about 10% off. So when you are doing 40 on the speedo you are probably doing 43-44 on the road. When you figure your mileage, you will also need to figure about 10% added on to the miles you have driven. That will make the numbers look a tiny bit better. Staying out of the right foot and keeping tires inflated on the highway will probably help more than anything you can do cheaply. How is the power? Did you notice a drop off after the lift and tires? You may be overcompensating for the loss of power by driving more aggressively.

Just food for thought...
 

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Discussion Starter · #5 ·
No, good statements. The power feels about the same.l It has excellent torque on the low end for sure. I dont know what gears are in it to be exact. I am esimating mileage of 10-12 mpg. I dont think the oversized tires really had an effect on the gas mileage to a LARGE degree anyway. Regardless, are there any universal mods that you all do to help this dilemma? Exhaust air intake, anything!
 

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Pushy, Loudmouthed, and Ballsy
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Some people say they get results from those mods. Others say it is negligible. You can always take it out of gear going down hills and only make right turns. :eek: :eek: :eek:
 

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If you want a Jeep that gets good gas mileage, buy a Patriot. ;) Wranglers just don't get good gas mileage. Bottom line.
 

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Drive the speed limit and try some fuel system cleaner and also the higher octane gas. It was mentioned before, but you are driving a big box. Have fun and say good bye to good gas milage
 

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Pump your tires up to 35psi, harder ride but less rolling resistance.
Chevron Techron Fuel system cleaner
Keep it out of overdrive, keep it in D not OD, OD only gets you good results on the hiway. My XJ with 30's, 3:07 gears, 5 speed gets 22mpg hiway at 65 in 4th, I never use 5th till I get around 70+. I keep that 4.0 right around 2900rpm which it likes. My 2.5 TJ with 30's, 4:10, 5 speed gets 21 on the hiway, I keep it at 65, and as close to 3200rpm as I can so it's a constant between 4th uphill and 5th downhill :D :D :D
Going to be interesting as I just noticed that the Hess station where I get gas in nj now has 10% ethanol, I never noticed the sign before so I may have been using it for the past 2 months. Will see if the TJ milage changes when I head home on friday for the weekend.
 

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higher octane fuel will only waste money dont do it it will defeat the purpose!!!

the car's computer is calibrated for lower octane and it will still pump in the same amount of fuel and then you will have more leftover in the exhaust you are spitting onto the pavement

The only suggestion i have is to lose whatever excess weight you have, if you dont plan on using the backseat take it out, or whatever, but 100 lbs more/less may effect your mileage by up to 2-3mpg!!!

one last thing is when you are at highway speed do you feel the trans lock in. Ie when you have been going at 60 for a minute will the rpms suddenly drop, they should as it locks in

and next time you get tires get the skinny ones they look cool and save on weight, and the power needed to spin then (centriplital acceleration if you are good at physics)
 

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Discussion Starter · #11 ·
I am sure those K and N air filters help with air flow to some degree, but they dont HURT gas mileage do they>?
 

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...and try some fuel system cleaner and also the higher octane gas.
Higher than recommended octanes do NOTHING to increase fuel economy. Octane has nothing to do with fuel economy. And all gasolines now have more than adequate amounts of fuel injector cleaners added to them nowadays. Clogged fuel injectors are darned near unheard of now, as opposed to the sixties and seventies wear it was much more common. :)
 

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I am sure those K and N air filters help with air flow to some degree, but they dont HURT gas mileage do they>?
Since the engine only draws the amount of air it requires and the stock air filter can flow more than the engine can consume, a K&N will not cause the engine to ingest more air than it does with the OE paper element air filter. Now in SOME cars, a K&N will allow the engine to breathe more easily but that's not the case with the TJ that was designed with an entirely non-restrictive free-breathing air intake system. :)
 

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K&N filter will do nothing if you dont have a less restrictive exhaust. They will only make noise and let in more crap. The stock air box is no that restrictive, (he beat me to it)
OTOH the exhaust system is very restrictive new cat, muffler and wider pipes could increase mpg by up to 2mpg, but it wil also set you back about 400
cool sound is a + too

but really the only thing to do for a huge change in mpg is to get a WJ or Xj for commuting and then mod the h3ll out of what you have now and just use it on the trails

my suggestion is just watch your driving, go slow, enjoy having a jeep, consolidate trips, walk to places nearby and go in your jeep only when needed, that is the only real way to reduce gas intake everything else is marginal
 

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Discussion Starter · #15 ·
Hmm well with the gas prices the way they are I am thinking that the 400 will pay for itself eventually hahaha
 

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Hmm well with the gas prices the way they are I am thinking that the 400 will pay for itself eventually hahaha
Yeah about 36000 miles. Do the math. You don;t spend money in your ride to save gas mileage. you do it for the enviroment if anything or performance. And...you increase performance, so you use it. In turn, you use more gas. That's just the way it is. It always cracks me up when I here someone basically driving a brick in the wind say "I need better gas mileage" I mean come on, You bought a Jeep for good gas mileage? I say sell the Jeep to someone worthy and buy a Honda. Oh, and by the way, the Hybrids, the ones that cost about $7000 more than the gas models, They take about 7 years to pay for on average driving. I don;t know anyone who would keep it that long. Just go to Propane.;)
 

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as said above the bigger the tires the slower the speedo will spin so the odometer will count less when you are in fact going more (unless you changed the speedo gear but i didnt see you say that..maybe i missed it) Go off by how often you refil.. (if you drive the same amount every day) :)
 
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