wondering why i get 13 mpg?

Geeze, I got 18.4 mpg last tank of gas and thats with a 3" lift and 33" MTs, but ive been steady in the 16.5 to 17.5 mpg range.

 

My (2010 DC AUTO V-6 4WD 5' bed) truck has 265/75-16 tires, so now the speedometer is correct vs. the smaller /70 tires it came with that had it read too fast. I 'lost' about 1 mpg with the 1" taller tires in my MPG checks.

NOW: If City only: 14.5-15.5 mpg now. Around town: pretty close to 16 mpg. 50/50 hwy and town stop and goes: closer to 17 mpg. Pure hwy. driving: 18-19 mpg.

Air pressure in tires on the high side makes a big difference I noticed. My Hankook ATMs (a 42 psi max tire) do well at 38 psi on my truck.

No change after I added a bottle of Techron, no change after new spark plugs installed at 30,000 miles either.

I do see better mileage when I put a new air filter in. So, after a lot of off roading, replace it!

I also HATE that the eco-nazis make us dilute good gasoline with 10%ethynol. In Baja, my mileage is always best using PEMEX (Mexican) gasoline (no eco crap in it)!

JOIN FUELLY.COM and have your mileage post automatically here (see mine below)...

 

If I am not mistaken, the standard tire sizes for 6-lug tacos are:

245/75/16 (steelies)
265/70/16 (TRD offroad)
265/65/17 (TRD sport)

 

That is correct... I have the OFF ROAD which came with BFG Rugged Trails 265/70-16. I replaced those crappy tires at 20,000 miles with Hankook Dynapro ATMs 265/75-16... as I said above (/70 to /75)

 

But that doesn't correct your speedo, you are now going faster than you think you are. Standard tire sizes are all around 660 revs per mile, you are now at about 637. You are now going 3.5% faster than your speedo says.

But, that means you are getting 3.5% better actual mileage than your calculations might say.

 

IMO what type of tires you are running and at what PSI is like 80%. Next, would be a good quality shock absorber.

When it's time, I'll probably install stock sized BF GOODRICH COMMERCIAL T/A Radials (all I can say is they are SUPERB) and test the PSI up to 50 PSI!

 

Or try these!SUPER SWAMPERS!

 

i have same as you 33's 3'' susp. lift =13mpg .......... on the 21st it' will be 6'' susp 35x12.50x17 pro-comp m/ts 4.56gears trd cai & catback what do u think it will be then?????

 

3" suspension, 33" Nitto all terrains, and my last tank was 358 miles with about 80% highway cruising around 80.. figured it out to be around 18.9 MPG..

This current tank, im at 342 miles and the low fuel light isnt even close to coming on.. gonna be my best tank yet. miles are split almost 50/50 city/highway.. not sure how or why this tank is so good.. lol but lovin it.

 

^^ This. OP, you said you have 60K, well that's a pretty big service interval where all of the things Stubbs mentioned above should get a good cleaning. Carbon and other crap builds up in those parts and tricks the computer into wasting fuel.

Having said that, I used to get around 18.5 mpg when my truck was in the first couple years of its life. My average nowadays is down around 15.5 mpg.

 

I used a GPS to see the difference.

The truck's speedometer gives a number based on the rolling tires. A GPS gives a number based on your actual speed.

The truck, with stock 265/70-16 tires was doing a true 65 mph while the speedometer indicated it was doing 68 mph. Toyota knows this, as do most here on TW.

With a 1" taller tire (265/75-16) My speedometer and GPS are reading the SAME mph!

Now, not as scientific, but my observations have been the odometer is also slowed down to a more correct reading. Before the new tires I always got 16 point something miles per gallon (around town)... now it is 15 point something (around town). I don't know how the speedometer and odometer could not be related... I mean one is measuring time to cover a distance and the other measures just the distance.

 

I average 16. Its all about driving habits, weight kept in the vehicle, tire pressure. Intakes/exhaust doesn't necessarily increase anything. I tested less mpg w/ a k&n cold air.

I used to calculate with a gps, now I do so with a calibrated Ultragauge. Speedo is way off so its no good for #'s

 

im getting 13 in the city with a heavy foot and bigger tires than stock

 

Blaming it on the West Virginia hills is a correct statement.I lived in West Virginia until a couple years ago and now live in upstate South Carolina.I can get 3 to 4 more MPGs in South Carolina than in West Virginia.I also have a Prius and the MPGs drop around 8 to 10 MPGs in West Virginia.The hills and the colder weather makes a big difference.I also have to question if there is different winter gas mixtures for different parts of the country.

 

According to puregas.org a Cenex station in Wichita has 87 that is ethanol free.

 

how are your math skills?

 

Well how far do you drive each trip will make a huge difference. I work 2.5 miles away all 25 MPH driving. I get about 8MPG if I never make a longer trip on that tank. If I drive on the hwy it'll jump right up to the 16-17 range. That's with 33's winch armor etc. light foot or not if you only make short trips your just guzzling fuel.

 

all my driving is around town with very little on the freeway currently. I am getting some crap for mileage for sure but am not surprised, am actually more surprised by others numbers in the 18+...

 

good to know I'm not alone but sucks for us... cant believe some of you guys get 18+ mpg... must be doing lots of highway to get that kind of number... i do both highway and city, about 40/60...

 

It is pretty amazing to see the difference that all highway (or almost all) driving does to city/ town driving (with stop and goes) on the Tacoma's mileage.

The past two weeks I have been working 20 miles from home, mostly freeway and my typical daily around town mileage of 15-16 went to 16.8 the first tank and 17.2 the next... at this moment, based on the gas gauge I am about 18+ mpg on this third tank. That helps with 'cheap' gas here now over $4/ gallon!