Gas Mileage Sucks

You need a scangauge, ultragauge, or equivalent. You're doing something wrong with your new habits.

Hypermiling is kinda like cooking - tips are nice, but unless you know how it affects the entire recipe, you could ruin your dinner.

Keeping RPM down - this is good for mileage. However most people will push their throttle way too much to compensate, completely flushing away any efficiency gains. This engine likes 75-80% load, and not over, for the best mileage. That means shifting at 1800 rpm takes a third of a mile to get to speed. Need to accelerate faster? Increase the RPM, not the engine load.

Coasting in neutral - this is a mixed bag. Properly used it does increase mileage a little bit, but nowhere near as much as a car. The truck weighs so much that the rule of thumb to guess how much fuel you're saving is how much you're minimizing your brake use. Coasting from 55 to a stop on the flat will easily take a third of a mile, which may tick off those behind you. If it's an empty road, then great. Otherwise, coast down in gear. Injectors only shut off if the RPM when you let off the gas is over 1600, and will stay off down to 1200, so keep that in mind. Also, the engine will idle at 1300 rpm instead of 700 rpm when coasting at speed, using 0.6 gph instead of the normal 0.35 gph you'd expect at idle.

It can get complicated... once you're into it you may feel like a warp core engineer

 

This graph is no longer correct for the modern automobile. I'd wager the study it refers to goes back to the days of unlocked torque converters.

This truck gets the best mileage at the lowest speed you can do in top gear while keeping engine load low. On the 6 speed, that's about 35 mph, and it's good for anywhere from 30 to 40 mpg on the flat. On the automatic it would be the lowest speed the torque converter locks in 5th. Every speed above that reduces the mileage, and of course the faster you go the less efficient you get.

 

To those complaining about another as mileage thread..Don't read it. I am and have been fully aware that this truck gets crappy gas mileage. I'm looking for helpful advice from people who drive the same vehicle I do. Seems like a semi-valuable effort. I could have used the search but there's more value in getting up-to-date advice.

I did, and a car at 30mpg will save me $200/mo right off the bat (and this is including keeping my truck). That's based on a pretty accurate estimate of the miles I drive in a month (ends up being about 2300) and including oil changes and insurance. Calculating incidental maintenance really shouldn't be factored in. My truck could blow up at any moment too. I don't know what $200/mo means to you, but to me it's significant. I make a nice living, but that $200 can be used in better ways than putting more carbon dioxide in the atmosphere.

I addition to this, I got my 2007 last year with 28k miles on it. I've managed to double that already. These trucks have a killer resale and at the moment I owe 5k less than the average trade value. That's great and all, but I'd rather not pile another 25k miles a year on this thing.

 

Thanks to everyone thus far. You've been helpful and it's appreciated.

 

It will save you $200 a month after calculating what insurance, maintenance (I assume it will be an older car after all), and the price of the car? I had a paid off newer scion and it still didn't make sense to have two vehicles to "save on gas." I wouldn't have bought the truck if I cared that much about a few hundred a month.

 

I wonder if a full belly plate would help much

 

I found the truck gets the best mpg keeping rpms down, no quick starts...ie the right foot mod.
Had a scangauge for about 2 yrs then sold it. It definitely came down to monitoring my use of the gas pedal.

 

I feel your pain man (I drive 70 miles a day) when my truck is paid off in a few months I am going to get a car that gets at least 30mpg for a DD. I will keep the truck for use on the weekends.

 

OP - Is this a manual? I'm assuming if you're coasting in neutral. Also burn through a whole tank before calculating mileage. I have found I get much worse mileage on the 1st half the tank than I do on the last half. For one, ever gallon you burn is 6 fewer pounds of load you're carrying around with you.

To those complaining about mileage threads ... I get your point if someone just bought their truck and then is complaining 1st tank out. But the OP has a legitimate concern if his rock steady MPG has now suddenly dropped.

 

I have 07 too and my truck does 23-25 MPG on my 50 miles commute to work. I dont see how 30 MPG car saves money over the truck. Those trucks are capable of some crazy mileage which makes owning a small car not worth it. If I was in the same boat as you I would solve the mystery of why your truck is using so much fuel.

 

It is from the DOE site

http://www.fueleconomy.gov/feg/driveHabits.shtml

Estimates for the effect of speed on MPG are based on a study by West, B.H., R.N. McGill, J.W. Hodgson, S.S. Sluder, and D.E. Smith, Development and Verification of Light-Duty Modal Emissions and Fuel Consumption Values for Traffic Models, Oak Ridge National Laboratory, Oak Ridge, Tennessee, March 1999.

All the 90s models automatics in the study had lockups.

 

Thanks. Much more recent that I anticipated. I'd seen it floating around for so many years I had assumed it was much more antiquated.

I still maintain that it isn't correct for the majority of modern automobiles and even less so for vehicles equipped with manual transmissions (ask any dedicated hypermiler if they get their best mileage at 65 mph). It's not impossible to get good mileage at 65mph, my old Honda would turn numbers around 45mpg at that speed, but it would do better going slower. Either way that graph's indications are nowhere near the actual mileage behavior of this truck.

I do know that in the 90s the lockup behavior was often programmed to be far less aggressive, sometimes not engaging until 45 mph or higher on some transmissions, and unlocking even with relatively low increases in throttle to provide a smoother driving experience. Today they'll lock much earlier to improve those EPA ratings. It may have something to do with it.

 

I'm using the tips on my current tank. I'll report in a day or two. Someone asked if it's a manual--it's an auto. I save about 300rpm when coasting in neutral though. I think someone said it burns more gas though. How is that possible?

 

IIRC , the injectors shut down when you are coasting in gear

 

Actually a lot less often than is assumed.

Engine needs to be engine braking above 1500 rpm, and if you see when that is actually the case, it just isn't easy to spend much time there.

Certainly useful on grades but not typical commuting.

 

I don't disagree , I was answering the other poster's question .

FWIW , I live in a quite hilly area and the engine braking is great .

 

Just pointing out that it doesn't happen every time while coast in gear, in fact not very often.

 

i would smile to high heaven seeing anything over 20MPG on my truck. I usually get around 15-17.9. 15 when ive used half the tank romping through mud or snow or just messing around.

 

Ok..so if I understand you correctly, you're saying that the injectors *sometimes* shut off when coasting, which obviously uses less fuel. But, my RPM's are decreasing (lower than when in gear) when coasting in neutral and the truck is more free to increase speed, which gives me more distance during my coasting period, correct?

 

OK...I checked my tires. I thought they were fine, but I guess the cold weather snuck up on me. they were about 5lb low. I corrected that up to 31 (just to be sure), filled the tank, and even changed the oil and air filter. Air filter was a year old at least and was really dirty. Regardless, what I've read says that the air filter cleanliness has no real affect on mileage until it's at the point that it's passing almost no air at all.

Anyway...I felt the tires would make a big difference. I spent another tank driving like grandpa, coasting, anticipating stoplights, running stop signs, etc. I drove it down to the last 0.5 gallon. The only detriment to my mileage that I participate in is remote start. I had about 25 total minutes of idle time with that. According to what I've read, you only burn an average of 0.3 gallon per HOUR. It's also been between 45 and 60 degrees all week. And I don't know if I mentioned it, but this is an 07 TRD automatic.

Anyway..I got my best mileage yet..

A whopping 18.1. That's exactly 2 tenths of a gallon better than when I've done my usual 78mph on the interstate.

The only thing I can say here is that I just live in too hilly of an area. I'm in Eastern KY/SouthWest WV, and it's smack in the middle of the Appalachains. If you watch "Justified", I'm only about an hour from some of those spots and it looks exactly the same. Sad thing is, I'm right by I-64 and doing most of my driving there, but I guess it's just too many long, gradual inclines. They really are just barely hills, but I guess they're taking their toll on my truck when they're 5-10 miles long at a stretch. To go 65mph, I'm running right about 1500rpm one way, but 1900 on the way back. I could get a scangauge I suppose, but potentially gaining 1-2mpg really isn't worth the effort.

So...I give up I guess.

It's gonna be horrendous when the snow kicks in and I've got 300lb of gravel in the bed..lol. It seems ridiculous to spend $1,000 a month for my transportation but I would regret getting rid of this truck, so I shant do it. I'm glad I have a good job though.