My truck

I have a 1977 Ford f150 with a 302 it gets 15-17 miles per gallon does anyone have ideas as to how to boost gas mileage?

Drive down hill?

That mileage is not too bad for your truck.  I would start by making sure plugs, plug wires, etc are all in good condition.  You might have a compression test to see how worn the engine may be. Depending on your driving style you might be able to gain a few mpg by driving more conservatively. How old are the fuel and air filters?  Auto or manual transmission?

That’s about as good as you can expect to get out of this truck. You could check the gear ratio and see about getting a numerically lower gear set to put in there. It will kill performance, but might get you a little better mileage. You could also find a gas station that sells unleaded fuel with no ethanol added. That will give you better gas mileage for sure.

Get a newer more efficient truck.

the filters are less than a year old but the air filter is in an open cover

the gears are 2.50s I have a set of 3.25s to put in it though

thats all I can afford right now and I like the older cars and trucks better

it has an automatic FMX tranny

Putting in the 3.25 gears will give you better acceleration but worse highway fuel economy. I don’t know old Fords that well, but could you look into retrofitting an AOD tranny? There’s not really much you can do to get better mileage than you currently have.

Your mileage is perfectly respectable for that vehicle, however I’d get an air filter on it as soon as possible. While you could possibly run it forever with no filter, it is a good idea to keep crap out of the cylinders.

That’s actually very good mileage for a 33+ year old truck. My 74 F-100 got 7-9 MPG. But it did have 390 4bbl swapped in and 4.11 gears. But 15-17 MPG with and automatic no less, is exceptional. I’d be happy with that.

About 13 MPG in top gear instead of 17 MPG.

Drive no faster than 59 MPH and use 38 PSI in the tires. I did that once and got 17.7 on the highway. It’s unknown territory after that.

I ment it has a filter but it does not have the factory/case it has a chrome 15 inch one

its hard to tell exactly how fast i am going the speedometer is about 5 mph off

Make sure it’s tuned up and keep your tires properly inflated. Most modern V8 trucks get exactly the same mileage you’re getting. It’s a V8 and you’re driving an un-aerodynamic brick.

I know but at least it looks cool

If you have an open air filter on the engine it draws hot underhood heated air into the engine. This is not good for fuel mileage. Put the stock air cleaner back on with it’s cold air intake hose so cold air can be drawn into the engine.


I agree with Tester that an “open” filter case can adversely affect gas mileage, but for a different reason. Your stock system had a “heat riser” built into it that allowed air heated by the exhaust manifold to be drawn into the intake to help the engine to warm up faster. A warm engine uses less gas than a cold engine. Without that system, the engine stays cold longer and runs richer longer.

Drive with the (stock) tailgate up, and if you have one of those “aerodynamic” net-type tailgates, take it off and put the stock tailgate back on. People assume that the net reduces aerodynamic drag force, but this is not the case. The truck actually has less drag with the stock tailgate (up) than with the net. This is because with the tailgate up, a recirculating air bubble forms in the truck bed, reducing drag. Replacing the tailgate with a net causes the air bubble to collapse, increasing drag.