What was Ford's advertised claim for EPA hwy fuel mileage on that particular model? A good tune should meet that, even with today's ethanol-laced gasoline. I'm sure it was better than 9... Anybody know?

 

Dunno, but I found this sweet commercial for the 302.

 

Huh. 24 hwy? That seems ... optomistic. In a car, sure. In a truck? Hm.

 

Do this^^ and you could regear your axles to a more MPG friendly ratio. You didn't say if it was 4x4 or 2wd, but I recently did a Crown Vic front suspension swap in my 2wd truck, and I'm pretty sure I'm getting better MPG since the truck is much lower. I need to burn through a few more tanks to verify though.

 

I also say do NOT waste money on EFI. Remember that a Fuel Injected V8 from the 90's could only get 12-14mpg on its best days (and that was BECAUSE they had Overdrive). Lets do some quick math....

At 8 mpg, paying the current going rate for gas $2.50, it will cost $3,125 every 10k miles you drive.

At 12mpg (what your goal should be), at the same $2.50/gallon, it will cost $2,083 every 10k miles.

So you will save $1,042 every 10k miles.

The best bang for the buck will be Overdrive. Multiple ways to do this -- AOD, E4od, ZF5 or 6, GearVender, etc. As example, it would cost around $4000 to DIY an E4OD into a highboy with divorced transfer case. You have to drive 38k miles to "make back" the money from doing that swap (roughly). Of course, that doesn't take into account the less wear/tear on the engine, less hassle for more gas stops, quieter/better driving experience, and other benefits of OD.

 

Embrace the power of "AND", nothing wrong with tuning it up and overdrive? There's no reason to waste fuel with a poor tune, it just wastes money, fouls plugs and dilutes crankcase oil, washes rings and excess cylinder wear.

 

Absolutely right. I would do all the normal stuff first -- tuneup, filters, good oil, ignition etc. In addition, change all fluids to full synthetic (axles, t-case, steering). Worth it in the long run. Then do the overdrive.

If this is a 2wd that won't tow much and less than 500hp, do the AOD. If 4x4 or towing, do the e4OD. If it has a 4-speed, maybe look at zf5/6.

 

I appreciate all of the replies fellas, picking it up this weekend. I'll be tuning it up asap and go from there.

 

I have a 74 2wd crew cab with a 390 nothing special about the motor. I took out the dura spark and installed a msd 6a box and stuck in a blaster coil.
When I parked it ,it was getting 15 in town and around 17 on the hwy. But this was before we had crap gas.

 

Reduce weight, reduce drag on the engine, lower rpms, optimize air/fuel ratio, reduce drag on the vehicle.

Electric fans help and are relatively cheap.

Ive said this before on another mpg post, what you want to recreate is a truck Ford built in the 1990s. Those trucks had electric fans, overdrive, and fuel injection. Those trucks maxed out at 16-17 mpg with a 302 or 300 six.

Most mods will not pay for themselves, but it's fun to wrench sometimes. There are other hobbies that are just as expensive.

Lighten frame, body, axles, tires, rims, engine, etc. Use aluminum or fiberglass where possible. Ford 8.8 or dana 44 rear end might be lighter and have less drag than a ford 9-inch.

Around 1980-1981 ford offered F100s with lightened frames. They had holes cut out on the frame rails.

Use a small displacement engine. You could replace a 302 with a 260 or 289, or a 300 with a 240.

Use a small cfm carb.

Use an open exhaust to help the engine breath. Headers, dual exhaust.

Improve the Compression over stock. Most of our trucks came with 8:1 compression. Bump it up to around 9.5:1 for increase efficiency.

Use heads with canted valves (ie. Cleveland heads). These can be used on 260, 289, 302, 351W engines to make a clevor engine. I read some engineering article on canted valves (ford 460) that said canted valves are 5% more efficient.

Use roller cam and rocker arms to reduce drag on internals.

Some tires are advertised to maximize fuel economy.

There are fiberglass body panels available for these trucks, but they are expensive.

You will have to research all of this and weigh the cost vs return. It would cost a small fortune to trick out an old truck with all of this, but it is possible. The end result? Who knows?

I would guess that this would all cost as much as a new truck as you are basically re-engineering the vehicle.

Or they sell tesla electric motor and axle kits for around $12k.


Most of all remember that these trucks have the aerodynamics of a brick. Good luck!