3.4 mpg

If I get between 10 and 12 mpg It is about normal.

Then it is always loaded and most times pulling a Tow behind welder the few times I think to check

Any extra weight or anything to increase wind resistance ??

I think a fuel leak would be easy to smell .

 

This one would probably be obvious but are you certain there’s no dragging brakes?

 

285/75r16

4.10

Truck is unloaded and is mostly highway miles.

 

Oh good, another MPG thread.

 

Lol. I thought the same thing when I saw it.

 

yeah that's bad lol. Mine's not great but I still get at least 200 to a tank with about the same tires. Start with a comprehensive tune up (oil change, air filter, new spark plugs/wires, clean the MAF sensor, etc.)

Got any check engine light codes on? With mileage that poor I would imagine you have a fault code stored in the system at least. Or a pending one. Need a code scanner to check or have an auto parts store do it.

Feel your wheels after driving and see if they're hot. The brakes will be hot obviously (don't touch those) but if the wheels are super hot then you have a stuck caliper

 

Gears are 4:10. Tires are 32.7 tall. Just dont seem to get hood mpg. Has new air filter. Just stump..

 

I have 285 75 r16 STT Pros and I get way better fuel economy than that. Something else has to be going on

 

You have a supercharger?
Do you drive it like you wish it had a supercharger? It's very easy to get these things just chuuuugging through the gas if you romp on it.

 

No supercharger. Drive it like a old man. I'm 54 lol.

 

130 miles to a tank definitely means something ain't right...I get bad mileage with my supercharger and extra weight/bigger tires/etc. and I get at least 200 miles to a tank, usually around 220.

The best way to trouble shoot this would be to hook up a scanner and read some numbers from your ECU...find out what your long term/short term fuel trims are for starters. If you have a vacuum leak or are running too rich for some reason then those numbers will reveal that.

All you need is an OBDII plug in and an app on your phone that can connect to it, like the Torque app. Can get both for less than $40, it's a valuable tool to have.

Also don't forget that since you have bigger tires your mileage isn't *quite* as bad as your odometer leads you to believe, since your odometer isn't accurately recording mileage due to the different tire size. But it's not very far off so it's still fair to say you're getting really bad mileage.

I think I remember reading somewhere that if you have 33s then your odometer/mileage is off by about 7%...so it's roughly 7% better than you think it is. But don't quote me on that I haven't verified it to be true.

 

If you think the 3.4L has "lots of power" I am 90% sure your MPG problem lies in your right foot.

 

I have 35's, 4.88 gears with an auto. Trans and I get 17-18 (combined City/HWY). I also get about 280ish from full to empty (Fuel Light On).

 

Something definitely is going on then lol

 

Here are some tips about the Toyota 3.4 Liter motor including fuel consumption. Because this motor has had an extraordinarily long life span, we are still talking about this motor. Most other automobile engines from other manufacturers from this era are at a happier stress free place at this point in their existence. LOL

There are many theories as to why this 3.4 is overbuilt, and I, personally, have not verified many of them. One of the reasons, I have heard is to why it was over engineered is because it was originally designed for industrial purposes, and Yamaha Corporation designed the heads for the little beast.

The 3.4 was off the drawing boards and into production around 1995. It has a cast iron block with quite sophisticated aluminum heads. It was originally intended to compete with the Chevrolet 4.3, and Ford 4.0 engines. At this time, Toyota wanted a motor with good horsepower and torque to compete with their competition. Fuel consumption was not their primary concern when introducing their 3.4 to the public. The mid 1990s was the start of the this whole horsepower war, which we are still going through today. The 3.4 achieved good horsepower and torque numbers at the time because of its engineering rather than its size. It put out about 190 Net Horsepower and 220 Foot Pound of Torque. These are very modest power output numbers by today's standards, but at this time, these numbers were quite respectful.

The EPA has, obviously, tested this Toyota motor quite extensively, and their numbers for fuel consumption are right around the same numbers that Toyota indicated the motor would get. It gets anywhere between 15-18 miles per gallon with stock trim. Strangely enough, the automatic does a little better. It gets anywhere between 16-19 miles per gallon. From the tests that I have done with my Tacoma, it gets exactly what the EPA says it will get.

Hope that helps,
Paul

 

3.4 mpg is not very good. that's like a fighter jet.

 

My 98 extracab 3.4, 5 speed, 4x4, 285 75 16 KM2's with 4.30 gears usually gets 17 mpg or so all around. 211,000 miles, if I drive like a grandma I can squeeze 20 out of her but that's no fun.