I need help! I have a 2007 tacoma double cab 4wd v6, 18,000 miles. I am getting about 14mpg and I baby it. haven't beat it up or anything. bought it a month or so ago. Trying to figure out why I am getting 14 mpg. Any ideas on what may cause that? I was thinking of carrying it back to the dealer, but I know that they're going to tell me that they can't find anything wrong with it. It's in Odrive, no hard starts at the lights, no hard braking, no load in the back. this is really bugging me. any suggestions?
Stop babying it and floor it every once in a while. It clears the exhaust of any unnecessary moisture and keeps oil pressure up.
The rest of your problem can be attributed to oxygenated gas and ambient temperatures (assuming your driving style and speeds are similar between fillups). When the AFR sensor detects extra oxygen in the exhaust, it tells the ECU to inject more fuel to burn it off (but the fuel is oxygenated, so it really doesn't help anyway).
Low ambient temperatures contribute to the loss in fuel economy, as do seasonal winter blends. The ambient temperature affects air density, and the blends change fuel volatility.
Some other things to consider:
Open loop vs. Closed loop operation
WOT and acceleration (this is why city driving, and stop and go traffic are terrible on MPG) are open loop programs meaning the ECU does not take any external sensors into account during the fuel injection process. This means NO adjustments are made to the base fuel maps. The base fuel maps are determined by engine RPM and intake air volume only. Cold starts are open loop, which is why you'll often smell gas in the exhaust from the engine running a bit rich.
Idling and steady speed cruising are closed loop programs after the coolant temp reaches above 120 degrees F. This program takes ALL sensor inputs into effect to adjust the base fuel maps. Closed loop operation can decrease or increase fuel injection amount by determining sensor readings (this is where you lose MPG from oxygenated fuel - 10% ethanol blends). This will also cut the fuel injectors off when your foot is off the gas pedal.
You should also consider using a 0W-20 or 5W-20 oil if you aren't already using it.
I average 22mpg during 100+ degree summer days, and 18mpg during colder winter days. However, this average drops to 16mpg if I drive in temperatures below 40 degrees for a long period of time and if I use 4WD in snow (of course). Tire air pressure is 35psi and I'm relatively smooth on the throttle. When getting on the freeway, I still punch it and achieve good MPG figures due to steady cruising (cruise control helps).
winter gas ;-D
a few post on other forms about millage going to hell all of a sudden
winter gas = hi ethanol content=gas millage sucks
and maybe a bit more time truck running while you scrape windows and maybe a bit more 4wd in snow?
so if about a month you could have been getting winter gas, we have had it for a few months already
- Don't forget your tire pressures decrease in the cold so double check them.
- Increased rolling resistance from snow.
- Do you let your truck idle/warm up while scraping the windows?
- Additives in fuel like mentioned above.
It all adds up and you're not alone. I'm getting 12-13MPG in my 2008 Double Cab Long Bed.
I need help! I have a 2007 tacoma double cab 4wd v6, 18,000 miles. I am getting about 14mpg and I baby it. haven't beat it up or anything. bought it a month or so ago. Trying to figure out why I am getting 14 mpg. Any ideas on what may cause that? I was thinking of carrying it back to the dealer, but I know that they're going to tell me that they can't find anything wrong with it. It's in Odrive, no hard starts at the lights, no hard braking, no load in the back. this is really bugging me. any suggestions?
chris
First off. What size tire and wheels? If the truck had 16" wheels new that is what it is geared for. Compare the tire size with what Toyota lists as stock on the door post. You would be amazed at how quick mpg drops with just 1" more rubber or a 1" larger rim. Tire pressure. Dealership techs will inflate tires to what is listed on the door post for stock tires without looking at the tires themselves. Go by what it says on the tire sidewall. Bug shield? Don't laugh. Some of them are so poorly designed they will affect your mpg. Check your air filter. Now it starts getting expensive. Injectors. A truck can feel like it is running fine with so-so injectors. Something wrong with the emmisions system can really hose up your mpg yet the truck seems to run fine.
OK, thanks all. The tires are factory, but I will recheck the pressure. No snow here yet until today, but it's not enough to use 4wd...maybe .5 inches.
however, i never let it warm up...maybe 5 seconds and I'm gone. i saw that a couple of you all mentioned that...is letting it warm up that significant to gas mileage? i can definitely fix that. i just didnt realize it was so relevant to poor gas mileage.
is letting it warm up that significant to gas mileage?
yep can affect the millage
look at it in a extreme way, if i got a tank of gas , drove home (say 2 miles) and let it idle for a few hours until empty i just got 10 GPM (gallons per mile ;-DD
and think winter gas is good for a few mpg by itself
10% ethanol and it alone gets way worse millage than real gas !
I can't believe you guys are getting that bad of mpg in winter conditions. I'm in Phx, AZ & have always gotten the usual 19-21 mpg in all conditions of driving; that is until the wife drives it in a lot of less than 2 miles from the house & it results in 16'ish. So I guess adding in really cold weather & a little snow on the ground & 14 is possible.
I know if I tow a trailer or add at least 600 lbs in the truck, my mpg goes down quickly. I wonder how bad the 4.7 v8 tundra/Seq. engine would do in your area.
Like all the suggestions above:
check tires
air filter
driving habbits
conditions
OK, thanks all. The tires are factory, but I will recheck the pressure. No snow here yet until today, but it's not enough to use 4wd...maybe .5 inches.
however, i never let it warm up...maybe 5 seconds and I'm gone. i saw that a couple of you all mentioned that...is letting it warm up that significant to gas mileage? i can definitely fix that. i just didnt realize it was so relevant to poor gas mileage.
Don't know how cold it gets where you are at but letting your engine oil warm up before driving will add many miles to overall engine life.
Don't know how cold it gets where you are at but letting your engine oil warm up before driving will add many miles to overall engine life.
Not necessarily. Oil pressure is more important than oil temperature at first (hence why oil companies developed 0W and 5W cold viscosity oils). You want the oil to circulate as quickly as possible through the engine to avoid wear. Idling doesn't allow that to happen, even with the thinnest oils on the market. Gently loading the engine (i.e. driving at low RPM) is much, much better on the engine. Not only is the oil circulating much faster, it's also heating much more evenly since the pistons, bearings, crank, valvetrain, drivetrain, etc. are all loaded.
Idling absolutely kills petrol motors faster because of low oil pressures.
Not necessarily. Oil pressure is more important than oil temperature at first (hence why oil companies developed 0W and 5W cold viscosity oils). You want the oil to circulate as quickly as possible through the engine to avoid wear. Idling doesn't allow that to happen, even with the thinnest oils on the market. Gently loading the engine (i.e. driving at low RPM) is much, much better on the engine. Not only is the oil circulating much faster, it's also heating much more evenly since the pistons, bearings, crank, valvetrain, drivetrain, etc. are all loaded.
Idling absolutely kills petrol motors faster because of low oil pressures.
Next time you start your truck cold check the rpm. The engine should run 4 or 5 hundred rpm over normal idle until it begins to warm. The oil pump should be operating within its pressure range here. This allows oil to warm, circulate and lubricate the valve train before subjecting the engine to driving revs. Thinking that valve clatter noise will go away if you add more rpm is just wrong. It's driving 101 not rocket science. Just give the engine a couple minutes to warm up.
Next time you start your truck cold check the rpm. The engine should run 4 or 5 hundred rpm over normal idle until it begins to warm. The oil pump should be operating within its pressure range here. This allows oil to warm, circulate and lubricate the valve train before subjecting the engine to driving revs. Thinking that valve clatter noise will go away if you add more rpm is just wrong. It's driving 101 not rocket science. Just give the engine a couple minutes to warm up.
It's also not rocket science to know that leaving an engine unloaded to sit and idle will cause wear. You will do what you want. The high idle on my truck jumps to 1500rpm on initial start, then drops to 1000rpm after 5-10 seconds. If that's optimal for you, that's fine. It isn't for me. I'd much rather drive and warm up the engine AND transmission.
And the valvetrain noise isn't caused by lack of oil/engine temperature on the 1GR. It's the solid, shimless lifters making that noise. It's the only GR engine with a conventional valvetrain and not low-friction roller bearing rocker arms. And it doesn't go away when the engine is warm. It's actually worse.
Your mpg is normal. My neighbors 2006 got 15mpg before he sold it. My 4Runner gets 16.5 mpg with the same engine. We both do a lot of city driving. During cooler temps the mpg is going to drop like a rock anyway.
2007 tacoma 14mpg problems
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