What's your mileage?

[ChrisDollins]

Our 66 got over 15 on the way home from a trip. 250/3 speed. I was really impressed with it. Ready to swap to a 5 speed.

Chris

[Lugnutz65]

I have talked to a lot of owners who want to improve their fuel economy.
The popular choices in no particular order are:
1. Keep the 3 speed and swap in a 3.08 rear differential
2. 700R4 AT with a 3.42 or 3.73 rear differential.
3. T5 5 speed MT with a 0.86 OD gear and a 3.42 rear differential
4. T5 5 speed MT with a 0.72 OD gear and a 3.73 rear differential
5. Tremec makes "bulletproof" 5 and 6 speeds but very $$$.
Fuel injection will help improve MPG as well.

Most importantly, match the rear differential with the transmission OD gear.

[66Submarine]

I think upper-teens is pretty easily achieved with a half ton (IME), at least if you aren't driving real fast. (Haven't been able to test how much of a hit you take from higher speeds, so I can't say for sure there.)

IMO, a 250 six or 283/327 (perhaps a 302?) with a manual OD trans would be at the top of my list if I was putting something together for economy. A good ultra-common 350 also works well.

Personally, I don't find these trucks to be really thirsty.

[joedoh]

Originally Posted by Lugnutz65

I have talked to a lot of owners who want to improve their fuel economy.
The popular choices in no particular order are:
1. Keep the 3 speed and swap in a 3.08 rear differential
2. 700R4 AT with a 3.42 or 3.73 rear differential.
3. T5 5 speed MT with a 0.86 OD gear and a 3.42 rear differential
4. T5 5 speed MT with a 0.72 OD gear and a 3.73 rear differential
5. Tremec makes "bulletproof" 5 and 6 speeds but very $$$.
Fuel injection will help improve MPG as well.

Most importantly, match the rear differential with the transmission OD gear.

good advice. an overdrive cog is a way to drive at highway speeds and lower rpm. which means the simplest way to get better gas mileage is not included on your list and is actually free, and that is to slow down. since air resistance is exponentially growing as speed increases (its the velocity squared part of the drag equation), the torque required to overcome drag at a speed of 70 is much more than that of a speed of 50.

I know a lot of guys who miscalculate their mileage too. I rode next to a guy in a ford last weekend who looked as his gas gauge, said "sheeeeet man we got 270 miles outa that half tank, thats 30mpg wooooo!". We then got about 110 out of the second half tank. Thats 21mpg. thats also what his truck is said to get for highway mileage on fueleconomy.gov. I have a ford focus and its gas tank behaves the same, first half lasts forever then plummets to e. When I went to lunch I had a 1/4 tank, this was driving home.