I recently put a new motor in my 93 Toyota truck. It's a regular cab 4cyl 4 wheel drive. Got everything done on the motor swap and fired right up. Finished off the first rank of fuel and it's only getting 11MPG???? What could be causing this? I understand most guys are getting around 20mpg. 31" tires on this truck doesn't help, but still should get better than that. Suggestions???

 

New Engine do you mean like new fresh and clean all shiny parts ??

Like rings and valves maybe not seated yet ??

Lots of people lie about mileage

Is it winter where you live winter blend can cause all sorts of people to cry about mileage

You have a meter on your fuel line so you are able to record every quart of fuel used??

If not how was the fuel use per mile calculated ?

To allow you to compute your figures

I have never attained more then 15 miles per gallon ever in any of my Toyota 4x4`s

In the winter it is around 10 to 12 I would guess between Winter Blend idle times and the hubs being locked

 

I do good to get 18 on an interstate with no stopping. If you are doing a lot of stop and go traffic as in city driving and not getting out of any higher gear then third, that will cut into your mileage. You need to explain the style of driving you are doing.

 

Another thing is where you live .

I am sure flat landers get much better mileage then what I get .

Then wind can really effect mileage cross winds are worse then head winds it feels like.

 

jesus, that kinda sucks, i have a 94 with a reman engine from napa, finished putting it in this past winter, here in windy kansas I am getting about 23 mpg running 87 octane (no ethanl), 225/75r15 with steel wheels as long as I am running about 60 mph. I figure out mymileage each fill up. while not super accurate, when I am constantly seeing 22 mpg, or 23 mpg, I am willing to call it good. if you do run ethanol gas in your engine your mpg goes down, on e10 my truck is 20-21 mpg

 

Reed you didn't mention which transmission or 2x versus 4x, both make a large difference almost as much as the nut behind the wheel. Kansas is very flat. That could be a tail wind in both directions depending on where and when you are driving which makes the wind resistance as low as 30mph constantly..

i got low to mid 17 in hilly terrain and steady winds. That's a lifted 4runner with oversized tires and an automatic (a340H, note that H eats a bunch of power) running a turbocharger. If my wheel nut gets loose that drops like a rock to the tune of a liter and a quarter per minute regardless of terrain or head winds.. I feel pretty good about that 17 if Terry gets 18s since he has tree cover and stuff (I miss green trees!)

Anyways back to the OP...

Start with the simple to over look stuff not related to the engine. Tires, properly inflated, not dry rotting. Wheel bearings, fresh lube and proper preload (my 94 picked up 2-3mpg from this, they were never touched in 20+ years). Brakes adjusted with new seals (another 1-2mpg there).. Doing the above changes there is a hill near my house I always coast down (1/3 mile long or more) went from losing speed to gaining speed (enough to get a big ticket if I'm not diligent and aware.)

You should get similar or better results (percentage wise) on a 4x4 in most cases there are lots more things to freshen up and re-lube..

 

To get over 15-16 we generally drive like the old folks we are. That's beside the point maybe anyway...

You have new sensors? TPS, oxygen, engine coolant temperature, and a recalibrated VAFM. (Worn out, dirty, worn and dirty, old and tired spring.. respectfully)

Quite a bit of idling on the first tank of fuel, how does it look after the second one?

I fill to the flapper give it time to settle and top it off. I try to keep good records but the damn receipts always fade, a trucker taught me to always copy off the fuel volume next to the mileage and date. My two wheeler has oversized tires that I never bothered to get a calibrated number for so those numbers are always lower than actual mpg (so put me on the lier list I guess, but in a good way I'd ya don't mind!)

Fifteen ain't so bad. Some people never grow up, good on ya sir fight the grey anyway you can.

 

i'd let the thread die, even though it isn't very old. OP has one total post, obviously hasn't provided any further feedback. and there are a plethora of gas mileage threads.

 

so some updated results, mainly the truck is driven to and from work, 5 to 7 days a week, some flat land, some slightly hilly (when I had an automatic crv (yuck) it would have to downsift with the cruise set at 65). I do occasionally get a tail wind but more often it seems like I get a headwind both ways. The Truck is a regular cab, short bed 4x4, 5 speed, 4.10 gears, has about a 3" lift in the rear because of overload springs. I don't constantly drive over 100 anymore cuz I am getting old, I try to stay at 55. things recently done to the truck, repack from bearings, valvoline full synthetic 75-90 in the rear end, front to follow shortly, am probably going to put gl4 redline in trans, new clutch when I put in the new engine. Stock tires almost worn out (30% left guestimation) with tons of patches in each tire. Tires normally inflated 32-35 psi. THe rest of the drivetrain has over 200k miles on it.

 

oh and I always shift before 3500 rpm, usually right at about 3000