Terrible MPG

I bought a 2008 V6 6-Speed AC on Halloween. I haven't put many miles on it, so maybe this is premature. I filled up when I got down to a QTR tank and calculated my mileage. I was around ~150 miles or so. It worked out to be about 13.16 MPG. So when I filled it up, I vowed to pretend there was an egg under the accelerator, and rarely went over 2k RPM wholeheartedly thinking I could do better than 13 with a little love....until I filled it up again and calculated 12.2 MPG. WTF?

When I first got the truck, I was driving a bit aggressively, not worrying much about MPG until the first fill up. Then after a 13 MPG shocker, I drove easy as shit for a while and now I get lower MPG. I don't get it. I was completely expecting a range of 14-18. I've only had it 6 weeks and never got below 1/4 or 3/8 tank and have only filled it up twice. I figure I'm F'ed, I accept it, but as an Engineer, I gotta believe that if it aint broke, fix it.

Does anyone have any ideas on what the hell is up, It has got to be better than this?

Info:
2008 Access Cab TRD Off Road
V6 - 6 Speed Manual
Pretty much stock, nothing added yet.

 

The 6 speed manual gets harsher mileage than the auto. Only thing I could trace it back to would be your driving habits, take it easy and don't be a heavy footer and it should improve. Being 6 years old it might need a tuneup also, dirty air filters, old spark plugs, or low tire pressure would all contribute to bad MPG.

 

what size tires and what psi are you running?

what is your driving conditions (mountains/only highway/etc)?

how do the spark plugs, oil, and air filter look?

 

^^ this

has all the maintenance been done? The v6 needs the plugs changed every 30,000 miles. Is the truck completely stock?

 

X2
Yup

 

I bought the truck stock AFAIK. It had 74000 miles on it. Looked like it came out of a showroom. (Now that I think of it, Low miles probably because he 1-Owner before me got terrible gas mileage) There was not even a speck of dirt in the engine compartment, the inside was clean as all get out, the underbelly is immaculate. Basically I don't think this truck has ever even seen a rock or dirt road, at all. The reason I liked it was because the dude had it serviced at the Toyota Dealership every 3k. I got service records and a Carfax with it. No shit, not one missed, every 3k on the dot basically. So Long rambling story short. I believe the maint has been done religiously. I also believe it is 99.9% stock, The .01% is a Chrome Stem Cap on the Right Front tire. Bling Bling!!!

So, I haven't really had a chance to mess with it, and to be honest I never even thought of tire pressure. It was serviced 12 miles before I bought it. I just went out and checked them. Ranging from 26-30 PSI. That seems low to me. The tires are 265 70R16.

The Oil is only 400 miles old and looks nice and clean.

I haven't looked at the Air Filter or Spark plugs yet. My intention now that y'all mentioned it, is to tear into it tonight after work.

Driving conditions. Since I bought it, not long ago, I have really only driven it to work and back. If we go anywhere, we usually take the Family Car. The drive to work is .3 miles to highway, 3 miles at 55MPH, then .2 miles into parking lot. And then on the way home I take the backroads and max at 35MPH, city driving no more than 4 miles. I'm aching to find some trails around here, but cant seem to find the time as most I haven't found are presumably a ways off. So I haven't loaded it up on the freeway for an extended amount of time. Maybe it will do better cruising at 60MPH than around town.

Sorry for the rambling, I'm long winded but I feel that it provide better information than just short answers.

I'm fixin' to get home and air up the tires, check the AF and SP tonight.

Thanks for the help

 

Change the rear diff oil to synthetic and air up those tires. In fact in all those receipts has the rear diff oil ever been changed?

 

does the truck get warmed up all the way by the time you're at work? Seems like your bad mileage might be in part from really short trips.

 

My 2011 6 speed was getting 13mpg recently, I took it in for a full tuneup (spark plugs, filter, rotate tires, ect)

My 2 tanks since the tuneup: 12.5 and 12.7mpg.

6 speed is a useless transmission in these trucks.

 

With driving distances that short you will always have crap MPG.

 

In town, stop and goes, city traffic... 14 mpg is what my automatic 4WD V-6 Double Cab gets.

On the highway, cruising empty bed, not speeding... 19-20 mpg!

My daily driving average is 16 mpg, sometimes 15.5. IT'S A TRUCK.

How many gallons did you fill it with when it was down to the QTR. tank line? It should have been about 13 gallons. I usually have driven just over 200 miles at the 1/4 tank line (205/13=15.7 MPG).

 

Im in the Tri-Cites. You probably know what kind of weather we get here being in Spokomton (Jester). If it is real cold, I let it warm up for a few minutes before jumping in a banging it down he highway. If it is like today, 40 deg, I usually just get in and go. Not balls to the wall, I like to let shit get flowing before I get on the HWY.

Before I get to work, It is usually warmed by the end of the HWY portion. Heater kicks on and blows warm sooner.

I didn't go thru them extensively enough to determine if the rear diff oil has been changed. Would it be safe to assume that the dealership would know to do that? I doubt it...

After a bit of thinking I've come to a bit of a conclusion.

1. Air Tires Up
2. Check/Change Sparkies - any recommendations for a good plugs?
3. Check/Change Air Filter - I seen the fitler recommended in the MPG Forum.
4. Replace Rear Diff with Synthetic
5. Short trips are probably detrimental. Take a trip and see how she does.

 

^ this

 

I understand that. I didn't buy a Truck to get good Gas mileage, I just thought it would be a bit better. Like I said 14-18. If I wanted great MPG I would have bought a Prius or some shit.

It was 146 miles/12.16 Gal = 12.026 MPG

 

In best mechanical condition you'll still have crap MPG. Your commute and vehicle choice don't mesh. I doubt any of the things you listed yield you a single extra MPG.

You'd see MPG loss with a Civic in that commute distance. That's the nail in your coffin. But good luck nonetheless.

Prius or EV is a better option for your trip distance, or ride a bike. Any car/truck will suffer.

 

Based on this you cannot get a good reading for MPG. Too many start ups (engine running rich), starts and stops, and short hops. Also the Northern states have some really sorry winter gas which gives very poor MPG.

Over the Thanksgiving holidays I drove to Ohio and back. I put about 2400 miles on the truck. Here in Texas I average about 22 mixed driving and 24 plus HWY.

When I left for Ohio I had the bed of the truck as well as the cab totally loaded. I also built a rack on the top of the bed rails and loaded a 10FT 2 Inch boat upside down and hauled it. Behind the truck I had a trailer with a yard tractor and the trailer was fully loaded besides the tractor. The truck was sagging like crazy from all the weight. I actually hit the bump stops at least once on my drive.

I left out with a full tank of Texas ethanol free gas. I got just over 19 MPG on that first tank. From there everything went down hill on the northern states E-10 gas. On the way back with nothing in the trailer or the bed (truck and trailer was unloaded) I got around 16.5 mpg on the crappy northern ethanol gas. So the winter gas in the northern states is really poor for MPG.

That being said I suggest that you fill the tank, and take a short trip HWY driving no stop and go stuff, and run the tank at least half empty or more at speeds around 60 or 65 and then you will see what the truck is going to do. By the way now back in Texas using E-0 gas I am back to my 22 to 24 MPG range.

 

Aside from all the great suggestions above, what is the weather where you are? These things will also contribute to low MPGs:

Cold weather
Driving in snow
Winter gas
Using 4x4
Remote start/Warming up longer than usual before driving

 

Yes, I just thought I would beat someone else to making that comment.
1) Keep RPMs to 2000 max
2) Tires evenly and correctly inflated, not over-inflated... new tires too!
3) Ethanol-free gas if available!

 

rabble rabble rabble truck rabble gas milage rabble prius

 

See post above. ->I didn't buy a Truck to get good Gas mileage.<-