Ways to improve MPG

On my '01, last time I checked I got about 14 mpg. I have 31" tires and apprx 3" lift.

I tried searching for this but didn't really find a question this specific. I figure this could help others.

Can you list modifications to do to improve gas mileage?

Cut the muffler off, and add a Thrush Glass-Pack for lower exhaust back-pressure. Makes it sound awesome, and on my '95, it picked up 2 MPG on the highway. My old muffler looked crushed and mashed it a few places. Also, air up the tires to 42 psi, and they roll better.

Buy a 4 cylinder sh*tbox. A metro, festiva, or justy will all pull over 40 mpg and can be had for under $1000. With the money you'll be saving in gas it will pay for itself in no time.

My vote is for a Festiva.

goblazers_6 said:

Buy a 4 cylinder sh*tbox. A metro, festiva, or justy will all pull over 40 mpg and can be had for under $1000. With the money you'll be saving in gas it will pay for itself in no time.

My vote is for a Festiva.

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My exact thought, except you beat me to it. :thumbup:

Lower it down 4.5" and pick up some 16" alloys with 45 series tires, Never go above 2200rpm.. never use A/C, never roll windows down.. 3-5 Yellow smelly tree's a must, Use shell gas..

OH! and maintenance.. new Plugs/o2 sensors/synthetic oil, take your roof rack off.. Get rid of all "armor" skid plates etc... tow package.. it all has to go!

You might get back up to 17mpg

with a 3 inch lift and 31's believe it or not your best bet would be regearing axles. 4.10's and 31's should bring you back to 15 maybe. Then after that everything scott said.

I have 95 with 3.73 gears and 285/75/16 Metric 33/11 running 35 psi and I get 17 around the Island I live on and about 21 on the freeway done with Nav and my speedo is just about right on maybe 3 % off @ 55 mph.

My mileage went to hell in the past 6 months. I used to get 18 on the freeway and 15 around town. Now it's 13 city/14.5 frwy. I've done a full tune up and an 02 sensor. All four wheels turn freely. Can't figure out what happened.
It seems from all my searches that half the modified rigs get decent (15-18mpg's) and half get crappy mileage, like me and you.
If you figure something make sure you post it!

What kind of Gas do you run? I run midgrade(89) Shell or Cheveron .Have you ran any injector cleaner through it I use Sea foam atleat once a year also what about fuel filter have you changed it ?

I am thinking of changing from my M/T's to A/T's to reduce the rolling resistance.

I usually buy gas at Fred Meyer since that's where the wife shops. There has not been a difference in mpg's between there and Shell/Chevron/76.

I did run two bottles of Lucas fuel injection cleaner. Have not tried the seafoam or BG44K which are the two that seem to be most popular.

Just find it odd that all of a sudden there's a %25+ mpg drop. Don't remember the exact time or if it took a gradual dive but it is definately worse than it was.

I think the increase of Methanol in petrol isn't helping our Heeps either.

My XJ took a drop in mileage too about 2 years ago for no reason whatsoever and there's nothing wrong with my rig. I did take off the splash mat and front skid though. Could those really add up to 2pmpg??
I just follow others suggestions above, especially keeping the pedal light and still pull 17 average. 14 in town short trips.
My tip is scan ahead for your next light and time it to avoid all reds i.e. stop n go.
Hypermill FTW.

If buying a beater to commute in is out of the question, and I'd imagine funds are tight since you're trying to save a few bucks on fuel.

Here is what I would do to save fuel if I had your XJ;
1. Maintenance. Have you done a recent tuneup? Checked for any vacuum leaks, exhaust leaks, alignment or worn steering components. Condition, pressure, and type of tire.
2. Lose weight. Take out anything not necessary. If you rarely carry people in the back seat, take it out and leave it in the garage until you might need it. Are you comfortable trading your spare tire for a plug and patch kit.
3. Drive to save fuel. Here are 108 tips on saving fuel; EcoModder. Take a look around that site too, it's pretty informative.

There isn't going to be a magical part you can buy to get better mileage. Gearing will help, but with only a 31" tire your return on investment wouldn't be worth it for years. Also if you are gauging your mileage off of your odometer, unless you corrected the speedo, it's off. A new speedo gear is under $50 and would probably be a good idea.

You could adjust your rear brakes to ensure the brake shoes aren't dragging!?