4 cyl 1st gen bad gas mileage

Hey guys, there probably is already a thread on this but here it goes anyway.

I seem to get really bad gas mileage with my 1st gen 4cyl 2.7l engine I am running at around 5.1km/l which is around 12mpg. I think I should be running around 20 mpg or 8.1km/l. Anyone else having this problem? anything I can do better, to the truck itself, not my driving, that could help ? I will start driving like an old man to see if it will help anyways. any help would be appreciated!!

 

What size tires?

Topper?

Empty bed? Tailgate up/down?

When's the last time the spark plugs and spark plug wires were changed? When's the last time the throttle body was thoroughly cleaned? When's the last time the MAF was cleaned? When's the last time the fuel filter was changed? Engine air filter also?

 

Has it always been like this or did it recently change?

 

265s

no topper
empty bed other than spare tire, tailgate up .
havent changed spark plugs since since I got it, air filter was change last summer, havent changed fuel filter.

it seems to be like this since I got it, maybe has been getting a little worse.

 

The spare tire in the bed is definitely messing with your fuel economy but, IMO, not enough for the discrepancy.

I would do the simple, and relatively cheap, things like change the plugs, wires, clean the MAF, take the throttle body off and thoroughly clean it (and while you're at it clean the IACV).... all of those could have negative effects on your fuel economy.

The fuel filter on the 2.7 is a PITA if I recall some of the stories, but it might be worth it too.

 

Fule filter is a Major PITA its under the intake manifold. but change plugs and clean the MAF with some cleaner (brake parts cleaner, carb cleaner, electrical cleaner, or MAF cleaner) but also you need to check what gears you have, I have a 2.7 5spd with 31s and i only pull 16 mpgs because i have 3.58 gear ratios.

 

Eroded gap on plugs, old plug wires, dirty MAF, dirty air filter, dirty throttle body butterfly and IAC valve, old and faulty o2 sensors, vacuum leaks or plugged cat can all contribute to poor fuel economy . . .

 

I'm getting 19-23 miles per American gallon. There is something definitely wrong with yours. Start with a thorough tuneup (plugs, wires, PCV, oil/filter, etc). Also, lube the drive line.

You may want to check the valve lash. Hard to adjust, but you can at least check to see if they need adjustment.

 

Thanks guys!!