Calgary Jeep Association

4x4 Related Groups => Tech Talk => Topic started by: mk333 on January 25, 2014, 01:37:08 PM

Title: Low gas mileage
Post by: mk333 on January 25, 2014, 01:37:08 PM

For about a month now I have noticed a decline in the km's I am getting with my Jeep. I have an 2001 XJ and usually can get around 500 km's to a tank but I am getting just over 400 now. I was thinking mabe a new fuel filter might be the answer but maybe you guys/gals here might have another idea. Tires pressure is good, new air filter and doesn't burn any oil. I've been doing the same commute for 3 yrs now..Carstairs to Airdrie every day so all highway km's. Any ideas would be great.

Title: Re: Low gas mileage
Post by: apeman on January 25, 2014, 04:10:43 PM

Fuel filter is built into the pump, which means dropping the tank. Have fun.

Title: Re: Low gas mileage
Post by: JENSSEN on January 25, 2014, 04:26:43 PM

Have you checked the Cat convertor, O2 sensors, has it had a tune up?

Title: Re: Low gas mileage
Post by: whitefang on January 25, 2014, 05:25:23 PM

agree with JENSSEN, check sensors then tune up!

clean throttle body, fuel injectors, new fuel filter
check spark plugs (if one is foiled test coil pack) change spark plugs, plug wires,
check timing.

for best gas mileage, run 215 75 r15 tires stock gears and no lift!!!

Title: Re: Low gas mileage
Post by: morerpmfred on January 25, 2014, 05:56:32 PM

Have been doing a commute to highriver everyday as well. Really windy the past month and  a half. Gas mileage in the big work van went way down as well.

Title: Re: Low gas mileage
Post by: specialk on January 25, 2014, 07:57:38 PM

Just carry a jerry can..  Or 2...   Its a jeep

Title: Re: Low gas mileage
Post by: birdo on January 25, 2014, 09:21:22 PM

Any chance your fuel gauge is out of whack? I would check O2 sensors for sure. They are good for about 50,000 kms then you really should consider replacing them.

Title: Re: Low gas mileage
Post by: Immortal on January 26, 2014, 09:31:08 AM

I was getting the same 500km/tank in my 99 XJ, then I switched to synthetic oil, transmission fluid, and gear oil. Started getting about 600kms/tank. But.... Wind played a huge factor in mileage.
I was about 50/50 city/highway driving.

Title: Re: Low gas mileage
Post by: birdo on January 26, 2014, 12:04:18 PM

Which reminds me.....I put synthetic in the gearbox last year and it made a HUGE difference to cold weather shifting and gear selection overall. Plus, I got rid of that stupid rubber shifter boot and replaced it with a nice soft leather one. HUGE!!!!!

Title: Re: Low gas mileage
Post by: mk333 on January 31, 2014, 12:32:59 PM

Thanks for all the info. I ve been thinking about going to synthetic for a while now. Spark plugs and O2 sensor are a good start.