I have 285's on my 6spd. It has BIG injectors and a few other mods and still gets decent mileage (18 to 24 US MPG) depending on what I'm using it for. Stop and go driving kills it and having a BAD VP44, goosed APPS, nackered CPS and crappy lift pump and you will experience all kinds of neato hits to the pocket book.

My DTE (computer thingy) reads around 750 or so MILES but I never ever get that high. It is usually around 575 or so. I have been able to get 735 out of it a few times running long distance at 65mph but this is seldom.

 

I hope your readin Kilometers here. I have never gotten better then 525 miles out of a tank and that was takin it to dry. My normal is around 400 to still feel comfortable but I usually fil up around the 350 mark.

 

I'm with Uncle Bubba, I get about 400 out of a tank. I dont count on mine because I never adjusted for the bigger tires though. I figure up between 15-17 but I have a heavy foot and big tires. If you are running 315's and 3.55 gears that is were your problem is.

 

Nope. The most I have ever got from my truck with a stock 135L tank is 1180 km!

1180 km = 733 miles. No BS. I've done it many times. From door to door Nanaimo, BC to Calgary, AB is 650+ miles depending on which way you go and I usually run the next day around town on fumes.

I'm talking 65mph cruise, 75psi in the treads, not towing and no topper or tonneau cover or whatever. Also, 6 spd. tranny, 3.54 gears, 285 treads, synthetic fluids and a good stereo...

 

I'm jealous as hell. Now I gotta wonder what's wrong with my truck.

 

I've never seen more then 17.5 when my truck was bone stock and that is a 2wd dually.

 

Your fuel choice is probably the first place I'd start. Next, look at the quality of your on board filtration. After that, look at how hard you take off from the stop light. The harder you go the more you spend. Then you can look at restrictions, air flow, fuel flow, chips, injectors and turbos...

Most guys build for power - I build for economy for the most part and the power is just added fun.

When you drive a long distance remember that the lower the boost is the better you are. More boost is generally associated with more fuel (harder pedal). I drive my truck similar to a commercial unit when I'm like that - the quicker I can get to the top gear and keep the boost low the better off the mileage is. You will be very surprised what having a non-hauling truck with 4:10's in it is doing to your mileage.

The new late model transmissions are different and the mileage is generally better in the auto's or so I'm told. I don't get that one to be honest but...

 

His nickname around the Island is GRANNY....and its not because he likes to knit (but he probably does that too)...

 

That's right you fat little... oh wait I can't say that here.

Seriously, I drive my truck - I can push it where I want to but would rather do that in the TD because whether you drive at 100 km or 140 the mileage is the same at nearly 1200 km per tank (HWY).