horrible gas mileage

My 2001 Doublecab supercharged 4x4 mpg has dropped 2-2.5 mpg.

driving conditions the same installed new plugs (dealer) and both o2 sensors.

Any other ideas? With the mpg drop I am worried about passing smog test.

Trying to find a pretest. OBDII showed no codes.

 

My co-worker is getting terrible gas mileage on his new 2011 dbc 4x4. He said its @ 13mpg. His truck has 1200 miles. Not sure if it just needs to get through the break-in period to impove or ? any suggestions, thanks

 

My mileage drops in the winter, I spend more time in very slow moving traffic and winter blend of fuel just sucks it down.

 

My winter mileage goes for a shit too

 

Im not sure if they blend gas much different in winter vs summer here in Cali? But I hear most taco owners complaining about 15-16 mpg. 13 just seems a bit too crappy. He might have a service tech look at it, for what its worth. I doubt they will be of much help. He said he's driving it like an old man, maybe thats his problem...lol

 

Pretty sure California is the reason most of us are stuck with a winter blend of fuel. I think it is suppose to burn cleaner in the winter months. Also driving like an old man is good if you are looking for higher MPG. I would also check the simple things like tire pressure.

 

So 1 MPG would be OK with you ?

 

ok that is the kind of bullshit answer that runs new members off. For fucks sake if you can't add to the discussion stay out of the thread.

 

Ya, I never expected my truck to be a gas saver. Thats why I kept my 93 accord that gets 32mpg. I use it as my daily beater and drive the taco when I want to be cool...or haul something. But my buddy is a bit concerned about his new taco and can't figure out why its not getting MPG anywhere close to what toyoya claims.

 

A lot of the mileage you get is due to driving habits. I know when I get a new vehicle I get really bad mileage for a while, until the newness wares off and then I start driving normally. If he is that worried he can ask the dealer to look at it, just make sure they agree not to try to bill him for it.

 

Agreed. Im sure it will get better, at least 3-4mpg. thanks

 

I've had my truck since September(installed tonneau) and my truck milage has gotten worse(first tank was 14.1L/100 km). I know that it's because I do have a heavy foot and I do mostly city driving. My last tank was 14.9mpg and I've averaged 16.1mpg over the last 2 years going by the fuelly website. I'm slowly trying to slow but sometimes it's hard lol. I'm learning though.

 

Just recently I tried upgrading the driver and got a whopping 4-5 mpg boost. I'm at 14k miles on a standard cab 4x4 4 cyl auto and was getting 19-21 on every tank. I was driving 70+ on the highway and not doing any of the hyper mile things I learned on the Yaris forum a few years ago. So now never more than 60, preferably no more than 55. Coast with my foot completely off the gas pedal for every stop. Never cruise with my foot barely on the pedal - coast and go back on the power instead. Shut off the engine at any stop that will be over 6 seconds. And of course accelerate like there was an egg under my foot. Since I've started doing all that my mileage for the last several tanks has been between 24.2 and 26.5 mpg.

 

15-16 mpg? So lucky. Mine doesn't have any suspensions changes or oversized tires. I get anywhere between 11-14 and 14 being best since I got the truck. These trucks suck the gas. I drive efficiently too. Keeping rpms under 2300, tire pressure checked, air filter cleaned, etc. I think I got a bad one out of the bunch or something. Idk

 

That's nuts. I have to have freezing weather, winter blend gas, run the defroster, and drive like mario andretti to keep it under 17 on the gauge. 11-14 means something is really wrong; my normal acceleration in 6th gear reads 12-13mpg on the ultragauge (and thanks to the MAF that sucker is very accurate once calibrated)! I'd check for stuck brakes, low fluid somewhere, a bad bearing, and so on. Even a crappy alignment could hurt here. 99.9% of the time fuel mileage is more a measure of friction losses than engine efficiency.

2300 is WAY too high for efficiently driving. Try 1700.

Maybe I'm doing something subconsciously. I know I come from a family that drove big rigs so my methodology is to maximize both clutch and brake life. After all how many people do you know who have gotten 12.2 mpg with a 5.7L Tundra pulling a 4200# travel trailer across the state and following the speed limit. It CAN be done! (FWIW the other driver got 8.4 mpg on his leg of the trip )

Some say I have a stage III patience module LOL

 

after wheeling and miles of 4hi/lo, I gauged my mileage at a whopping 8mpg last week

 

I drive like I stole it everywhere and get a consistant 16 mpg. my best was near 19 mpg round trip to vegas.

 

I know 2300 is way too high, but it's around that on the interstate. I keep it around 1500 around town and on city roads, which is mainly what I drive. 6 spd manual btw.

 

Mine's a six speed too. Gotta work the magic on it!

Ah, I see one thing right there. I think you can push the RPM down a lot more than you are if you're keeping around 1500 in town. Having put a few miles on the auto v6 taco I know Toyota designed that transmission's logic to push it down to the 1000-1200 rpm range whenever it can. It would seem the engine has a strong enough oil system for that low speed, but I guess we knew that from all the people on here that wheel frequently because otherwise we'd have threads on spun rod bearings every other week (and we definitely don't).

This means if you're doing 25 mph steady, that's minimum 5th gear; if there's any downhill at all put it in 6th, big uphill put in 4th. Steady 30 mph and higher is almost always 6th gear unless there's a massive hill, then use 5th. Example, if you're doing 35 mph and turning 1500 rpm that would be 4th gear. The mileage loss from 6th to 4th at that speed is in the neighborhood of 15 mpg. I watch the ultragauge all the time for stuff like this. Its an incredibly massive difference. Flat ground 35 mph stays 30-35 mpg in 6th, about 15-20 mpg in 4th. Without those high mileage cruising stretches you won't offset your acceleration fuel usage and will wind up with that low mileage.

I know Toyota put a crappy 0.84:1 6th gear in this truck. I mean holy rip my Honda had a 0.77:1 and that was a 91 cubic inch engine. We have to turn our 4 liters at 2550 rpm to go 70mph where the auto is more like 2100. Shoot even the 3.5L ford ecoboost on a 3.55 diff set just hums along at 1800 at 70, doesn't need to make boost pressure to do it, and that truck weighs a heck of a lot more!

I have tried tanks shifting at 2200-2300 rpm and it did drop a mpg or two off my average, but it wasn't that big a deal. Any acceleration at 80% load between 1500 and 2400 rpm is efficient, but the lower end is better.

The learning curve sucks on this transmission but it's not so bad to live with once you figure it out. One RPM range for accelerating, another for cruising, and don't mix the two until you run out of gears.

 

Im going to try your shifiting techniques and see if I get better mpg. I've been keepin it in 4th @ city streets up to 40mph most of time. thanks for tips