Mpg

Ok so a mix. Have you checked the air filter yet? If it is an oiled k&n, throw it out, install a Toyota, Napa Gold, or Wix filter. Clean the MAF sensor, change the plugs (number and take pics of them for us), and report back.

Oh and what psi are you running?

 

With everything you’ve told us about the Truck and your driving habits/style it’s still not adding up. I’m running e rated 285’s on a 3” lift driving fairly aggressively and I still manage 16-17. Even when all the overland gear is on my truck I still get 14. As others have suggested I would do spark plugs, clean MAF, replace engine air filter, get an alignment and do the brakes. Other questions that come to mind, does the Truck drive fine? Feel sluggish? Vibrations? Tire pressure? Maybe try changing where you get gas.

As far as calculating the mileage, you need to find out exactly what your error calculation is for how far you actually travel when your odometer indicates you’ve gone one mile (larger tires throw your odo off). For my Truck, my error is 1.12 miles to 1 mile on the odometer. Once you’ve found your error, fill up the truck (let the pump stop it and don’t keep pumping), reset the trip, then the next time you get gas go to the same pump and let the tank fill until the pump stops you again. Take the number on the trip calculator and multiply it by your odometer error, then divide that number by how many gallons the tank took to fill up. That is your “real” mpg. Good luck!

 

SOME of it may be gas..... we are on winter gas now right?

This may account for a couple mpg right guys?

But its just 1 POSSIBLE SMALL factor

 

Drive like there is an eggshell under the gas pedal

 

Are you dividing actual tire size by the stock tire size before calculating mpgs? You'll likely gain a little there. New spark plugs will help too. New air filter, clean MAF and throttle body. You'll probably get up into the 16s with all of this done.

 

You'll get a more accurate adjustment factor if you run 50 miles by mile marker and compare that mileage to what your odometer says, as opposed to just doing 1 mile. Just zero one of your trip odometers. Also, check your tire pressure. Hold off on tuneup, filters, etc until you know how much error you really have.

 

How will 50 miles be more accurate? Lol 1 mile or 50 miles or 200,000 miles, they’re all linear distance and your tires will make the exact same number of revolutions per mile regardless of speed or distance? It’s more accurate, easier and faster to drive one mile with a gps running that can show you hundredths of miles vs using mile markers.

 

1. OP might not have a GPS.
2. 1 mile, tires might be cold, 50 miles tires are more likely be at normal operating temperature.

 

Well guys I changed the plugs, cleaned the maf sensor and the throttle body and I'm Happy to say I got 19 mpg on my next tank of gas, oh and watched my driving habits (a little bit, old habits are hard to break)
Now what I don't get is, so I use my truck for work and on Mon I went through the first half a tank of gas and only drove 65 miles, Tues and wed I used a qtr tank of gas each day and drive 70 miles on Tues and 82 on wed. Now, with another full tank of gas i got 100 miles out of the first qtr tank, so I'm expecting I'll have even better mpg at the end of this tank but it just doesn't make sense to me why the it's so irregular?...
I hope that made sense to all you guys.

 

My totally stock truck gets around 20 mpg on the highway and maybe 13-14 around town. I live in a hilly area but drive gently. If you got 19 mpg driving around cleaning pools you did very well. No offense but I think your calculations may be off a little...

Nice looking truck by the way, welcome to TW! Lots af great folks on here willing to help out...

 

The computer is adjusting for the changes you made. It takes a few tanks of fuel.

 

I'd say lighter tires an a tune up couldn't hurt.

 

On a lot of vehicles, the gas gauge is not "linear". On my Tacoma, I can add over 2 gallons from when it first clicks off (I rarely do this, except when on a road trip and will be burning several gallons right away - but gauge does not move at all for the first 100 miles or so). Some vehicles the gauge seems to move quicker on the first 1/4 of the tank, others the middle. What you wrote above about how much you used day by day, my opinion is the best you can measure is tank to tank, not day to day. Eliminate what variables you can, use the same pump if you can. Other factors are more or less heavy traffic, more or less highway versus stop and go city driving, more or less air conditioning use, etc.

Keep a log of miles and gallons of 5 or 6 tanks to get a baseline of what you're actually using. It will change due to factors you can't control - winter/summer gas, cold weather versus hot summer, phase of the moon(kidding).

 

Lol, that's cute "phase of the Moon"
As for going 2 gallons over after the pump clicks... I'm actually worried bout doing that, I would fill my 4 runner full when I had the money to fill and now my check engine light has been on for 4yrs,I really don't want to risk it with the new Tacoma.
My calculations I tried it a cpl diff ways cuz I have an eye factor of .1 of a mile with my tires and 19mpg was the lowest of all my calculations, but I know I got almost 400 miles with this tank vs the 190 with the first tank. So I'm pleased.
Thank you all for your advice, you've all been a big help

 

When the pump stops, you should stop.

The evap system can throw codes and cause some serious issues when overfilling.

 

Don't forget you are using winter gas right now which is a lot worse then normal summer gas, just saying

 

This

A new evap canister will set you back close to $500. Never top off the tank