ryan78

iTrader: (2)

Reviving this thread as I am chasing the same issue. I have an 04 with 144k on the clock, and I'm getting roughly 150 miles a tank. I live 4 miles from work and there are a number of lights in between, however while I don't mind 15 miles a gallon, sub 10 is killing me. I never would have thought my 4.0 YJ would get better mileage, and it's on 35's lol. As I am so close, I do go home every day for lunch, so even with errands 20 miles a day is the max I drive with an extra 50 added in for weekends. This is not 100% accurate, just a guestemation, but close enough. I do have 265/75/17 A/T hybrids as well. I would not expect them to have that drastic of an impact, but perhaps they are contributing more than expected.

I plan on checking the TB and MAF, plugs were done about 20k ago with the 120k service according to My Lexus. Calipers are not seized. I had all fittings greased during PPI. Tech was surprised at how clean the truck is, but there is evidence from the mileage that it wasn't run much over the past 5 years. Only 14k miles in that time.

Can anyone offer any suggestions as to what else to dig into? I understood the poor gas mileage, but this is a bit much. I'm getting less than half what I should, though in fairness I did get close to 320 miles on one tank when I brought it home from out of state. Is this just a result of city driving? I am cognisant of the V8 and am light on the pedal.

Thanks

IanB2

Short drives don't allow the engine to get up to temp, and I'm guessing you aren't accounting for the larger tires in your mileage calculation? Looks like about a 6.5% variance that should be accounted for. So if you were manually calculating (like you should be), you'd take the miles travelled X 1.065 to get the corrected miles travelled for your MPG calculation.

I can tell you that idle time on these trucks is awful for fuel economy, so if you're letting it idle for 5min before heading out, stop doing that! I use the command start in the winter here as it's cold, and it decimates my fuel economy.

ryan78

iTrader: (2)

I don't let it warm currently, just allow the idle to drop and then go. It does get up to operating temps, but not too long prior to being shut off. I was wrong on my tire size, it's 265/70/17.

chiph9

Carbon build-up? Take it out for an "Italian Tune-up" one weekend.

Chip H.

Tinggi

Agree to the Mexican tune-up. My 2005 was never driven much at highway speed or for long trips. I have noticed an improvement in power, fuel economy, and overall engine performance after putting a couple 8 hr drives under its belt at highway speed. Also, a couple synthetic oil changes.

My Fuelio average (city and highway) is 15.4 MPG. If I stay at 60 MPH it will get 18 to 20.

ryan78

iTrader: (2)

I may take it north for Christmas, but otherwise no opportunity for a full tank trip. It's an idea for sure, but it'll likely have to wait. I'm hoping cleaning the TB and MAF will have positive impact. May change the O2 as well.
Thanks!

ALAN553

O2 sensors degrade over time without "failing" I read here somewhere that replacing them gets you back to the original gas milage