Gas Mileage Help

Hey guys, need some help. My truck is only getting 11 MPG. It seems to be running fine, but the gas mileage is horrible. With my aftermarket mods I expected it to get less than stock MPG, but 11 MPG is ridiculous for a Tacoma. Any advice on what to check or what you think is the problem?

Mods are: Volant cold air Intake, Doug Thorley Shorty Headers, 3" cat back exhaust, 10" magna flow muffler, 285/70/17 BFG KO 2's.

 

the tires are 58 pounds weight, stock tires weight 32 pounds, un sprung weight reduces performance the truck wasn't meant to push this weight tire to achieve maximum effeciency

 

That is about the fuel mileage I get 3.4 5 speed between 10 and 12 mpg

Then I really have not done a controlled test

 

Are you 4 or 6 cyl?? Manual or auto? Maybe you should regear with those tires. Even with my little 3.4 and 33"s I still get 18-20. 11 is horrible.

 

It's a 4.0 v6 auto. Ya I drove from Cali to Utah, then to Idaho, and about to head to Colorado and then back to Cali so I have a couple thousand miles left to go on this trip. I was thinking maybe a spark plug went bad or something like that but the truck still runs great so I have no clue. Guess I'll take it in and have someone run a diagnostic. Thanks for the info

 

Did it just start doing it? Or has it done it since you bought it new?

 

Click and Clack would recommend removing your mother in law from the vehicle.

 

Not abnormal based on your mods. I'm getting 12 to 13 right now with winter gas blends.

URD LONG TUBE, 33's (255/85/16), K&N Noise Maker, bumpers, skids, sliders, lift, winch...4.56 gears

 

265/65/17 E rated KO2's for me...stock exhaust/intake, stock suspension, and I consistently get 16.5 in the winter. Haven't had the KO2s for summer blend gas yet but I'm hoping to see 17. Just my 2 cents...

 

There you go. Stock truck with aftermarket tires. Terrible mileage compared to EPA claims.

 

265/70/17 P rated g2s and I get 17-18 on my 4.0 DCSB 4x4. So.... heavy tires equal bad gas mileage. lighter tires equals still not good gas mileage. And add ons like exhaust and intake won't help.

 

All on how you drive. Get a scan gauge or ultra gauge to see what affects your mpg and adjust your driving according.

You can get better then 11 mpg with your setup.

 

yes my mileage is 1-2mpg off from EPA (I drive almost all city and have a serious lead foot problem) but with how much the truck weighs I'll prob get 60k miles out of the KO2s. And not to mention I'll never ever get stuck. And I'd have to run over a nuclear warhead to get a flat.

That being said I'll probably go back to something rated a little lower and lighter when these wear down in 5-6 years lol.

Pick your poison.

 

When I bought it new I was averaging about 300 miles per tank, so about 17 MPG. With my mods and tires now I'm getting 200 miles per tank @ 85 mph on the highway. RPM at that speed is about 2600. I also went from Sea Level to about 5,000 feet and there's been quite a bit of wind... I was really worried that maybe a spark plug was bad or something like that but now I figure I'm just driving it really hard so it's sucking down gas...

You guys think if I add the URD MAF Calibrator and have them tune it for my mods I'll get better performance?

 

At 11 mpg I would have thought you had a shit load of armor and bigger tires. But now I see that you should really be coming in at 13-14 mpg's if your driving habits changed to 70 mph @ 2,000 rpm on the highways and slow take-offs that don't have your rpm's exceeding 2,200 or so. Try that for a week then report back.

 

I don't see these add-ons as part of his problem. Please explain.

 

With 265/70/16 and K&N, no additional lift (yet) I see about 15-16mpg average

 

They won't help in increasing fuel mileage.

 

I have 285/70/17 nitto terra grapplers and I can get around 17 or 18 mpg