Insanely Low MPG, Can't Get a Clear Answer, PLEASE HELP

Waasheem · Jan 8, 2022

Waasheem said: ↑

On mine, I usually get just short of 12 mpg. After a little bit of effort, I checked the fuel trims, it said to look for a vacuum leak. Found my pvc vent hose worn out, loose, cracking end. Found it when I replaced the plugs recently. For temporary, I repositioned the hose and clamp. The next fill up calculated to about 14.8 mpg. That includes a 2 hour highway drive. The next fill up will be a more accurate assessment. 4.0 v6, 6sp manual.

What I would suggest is to look through the stickies. In the maintenance post, you’ll find instructions how to clean the maf sensor and throttle body, changing plugs, etc. You’ll see plugs are recommended every 30k miles. Unless you’re certain they’re up to date, pull one and look at it. You might find what I did at well over double the mileage. Ngk one side, denso on the other, indicating originals from the factory, and dang, how’s it still run with a gap that huge. I would also suggest to not get spark plugs from Amazone, I received what I suspect were counterfeits.

Nice looking new to you rig. Welcome to the forum.
Click to expand...

I finally got around to replacing that hose that goes from the pvc to the intake. Repositioning the hose and clamp gave a slight improvement in mileage and fuel trim. Mileage went from 12.2ish mpg to 12.8ish mpg. I don't expect to get all that much improvement in mileage because I have horrible driving habits. Hopefully the fuel trim will improve some more with a tight fitting hose.

MonkeyProof · Jan 8, 2022

monitoring short and long fuel trims would be the best way of determining if there is truly a poor fuel mileage concern...

Waasheem · Jan 15, 2022

First fill up after replacing that worn out pvc hose, calculated to 13.09 mpg. Whoo hoo. The next fill up will tell the true story. I haven’t rechecked the fuel trims yet, or changed my driving habits.

Log in or Sign up

Welcome to Tacoma World!

Insanely Low MPG, Can't Get a Clear Answer, PLEASE HELP

#81
Waasheem The catholic radio bear

#82
MonkeyProof Power Top

#83
Waasheem The catholic radio bear

Products Discussed in

Log in or Sign up

Useful Searches

Welcome to Tacoma World!

Insanely Low MPG, Can't Get a Clear Answer, PLEASE HELP

#81 Waasheem The catholic radio bear

#82 MonkeyProof Power Top

#83 Waasheem The catholic radio bear

Products Discussed in Entire Site Forum: 2nd Gen. Tacomas (2005-2015)

#81
Waasheem The catholic radio bear

#82
MonkeyProof Power Top

#83
Waasheem The catholic radio bear

Products Discussed in