Horrible mileage in 2011 taco 12.8 hwy?

I just got this thing and I'm quite concerned. Just completed a test to see mpgs. I measured the miles I got (67) in a quarter tank (5.275 gallons) which comes out to 12.88 mpg hwy! WTF??? This thing will be going back if this can't be fixed! I drive all highway to work, 5th gear all the way from my driveway to the parking lot. Driving like a grandma too. Checked the tire pressures, running at 36 ish. This truck has 21k on it so it should be broke in. What could be doing this? I have the double cab, v6 auto, 4x4.

 

Shouldn't run the tank real low very often since the fuel pump relies on the fuel for cooling and lubrication iirc.

I think its also less accurate than filling the tank up, driving till 1/4 and then filling and doing the math for mpg.

I never pay attention to my mpg tho, so that's just a guess...... All I do know is I avg 320 to 350 per tank.

 

You should be getting close to 20 mpg in a stock auto. Is your check engine light on?

 

I'd also use 4th not "D" when not on the highway...... I'd assume too much searching may waste fuel,


Would it also be less effeciant to be chugging along at 35 or 40 in top gear as opposed to 4?

 

No check engine light. I measured from 3/4 to half.

 

you should be calculating your mileage by how far youve gone divided by how many gallons you put in. ex. you drove 100 miles, you topped off your truck and it took 10 gallons. 100mi/10gal = 10mpg.

and a quarter tank is aprox. 4.25 gallons, because your tank is 21 gal with a 3 gal reserve.

so even if you did 67 miles / 4.25 gallons, you are getting about 15.76 mpg. which is not bad

 

The most accurate way of calculating mileage is:

Fill your tank up and reset your trip meter.
Run through most of the tank, at least down to 1/4.
Fill up again and divide the miles on the trip meter by the gallons that went in on the pump.

Try that for at least a couple of tanks and take the average, I bet it is at least 17.

You could also use Fuelly or any other smartphone fuel economy app to do the math for you. I use FuelLog on Android. I have a DCSB 4x4 with less than 1000 miles on it and get around 18 mpg.

 

Doesn't the reserve still count to the total capacity of the tank?

 

This.

WUT?

 

Yes, but unless you run your truck down until it literally stops running from lack of fuel, you aren't using the reserve. Even then, you still probably aren't getting all 21 gallons out of the tank. When your truck first hits "E" and your fuel light comes on, there's still about 3 gallons left.

 

What they said ^^

 

OK. I will give that mileage test you all suggested a try. I'll do it 3 times. In the mean time, any fuel saving tips/tricks that have been proven to work?

 

Google chalk line test..... Then use it for ur tires and adjust as needed.

Maybe get an ultragauge or Scangauge and watch ur instant mpg and avg mpg.... Or see if ur GPS offers this, my Garmin does, its settings are deep in the software, but once enabled it is easy to use.

U enter gallons filled, and u can also enter price per gallon if desired.
Can be set so that every time u shut the truck off after a trip, the GPS stays on for 10 seconds and gives u the avg mph, mpg, and cost of the trip.... Not sure of its accuracy I don't use it often.

 

So you all are telling me that AFTER the last mark by E on the gas gauge there's an additional 3 gallons of gas? What does each quarter tank indicated on the fuel gauge represent? Just trying to get this pegged down. Forgive my seemingly hard headed ness. I am on midnight shift right now and it turns me into a zombie.

 

yes.

your tank holds 21 gallons. when the low fuel light comes on you have about 4 gallons left (used 17 gallons), when the needle is on empty you have about 3 gallons left (used 18 gallons).

think of it this way;

your gas gauge acts as if your tank held 18 gallons. so each quarter tank is 4.5 gallons. and when you get to empty, you have a 3 gallon reserve, to make it to a gas station.

 

"What does each quarter tank indicated on the fuel gauge represent?" I don't think that the quarter tank marks on the gauge equally divide the tank. I think the first quarter tank, from full to 3/4, represents more gas than the others. I get 90 miles out of the first quarter tank, and I'm sure I don't get that out of any of the other quarter tanks.

After the last mark on the gauge there are at least a couple gallons of gas. The gas actually cools the fuel pump, which is mounted inside the tank, extending it's life.

 

You know the fuel-gauge is non-linear, right? i.e. the first 1/4 division on the gauge will go down at a different speed than the second and third 1/4 divisions?

Just fill up until full, reset the trip odometer, drive a bit and fill up until full again. Divide the odometer reading by the number of gallons from the 2nd fillup.

Actually it's just the opposite. "D" uses less fuel. I lose about 1 mpg by driving in "4", but I do it anyway for the engine braking and better throttle response (since the rpms are kept higher). Of course, my typical driving is like this:

 

I'm going to do that, I just want to understand my vehicle better.

 

I just read in the FJ foum that bad gas milage can be caused by a weak thermostat stuck open on the 4.0's the temp gauge reads normal because we all know (hopefully) that the temp gauge is not very accurate and covers a wide range.
What happens is the truck doesn't fully warm up and stays in warm up enrichment.
An OBDII scaner of some type hooked up to read water temp would confirm that. I have a buddy that has this very problem and we are going to check this out in a few days.