Improving 76 Ford F150 fuel economy
#16
03-10-2018, 08:00 AM
Cargo Master
A dentside is a giant brick on wheels, period. The money you will spend to gain, maybe, 3 mpg better you could spend on a 15 year old civic or focus and get 30mpg. These trucks are built to work and make money, not save money at the pump. You just have to deal with it like the rest of us. Sorry for the bad news.
#17
03-10-2018, 08:30 AM
Silk willie is right. Any small changes you make will not make any effect that you will see in your wallet, but small gains in the form of fractions of a percent.
the two modern things you can do to actually see a gain, which will also improve drivqbility and driver comfort are:
1) fitech or other tbi system in place of your carb ($1000-2000)
2) gear vendors overdrive ($2500-4000)
these two items will make you feel like your driving a more modern truck, reduce wear on the engine and trans incredably, and reduce fuel consumption. The first two reults imho are where its worth the money. But if you dont have the budget doing all the small things mentioned above will help keep the truck running optimally in its current configuration, ie urning as little fuel as possible
the two modern things you can do to actually see a gain, which will also improve drivqbility and driver comfort are:
1) fitech or other tbi system in place of your carb ($1000-2000)
2) gear vendors overdrive ($2500-4000)
these two items will make you feel like your driving a more modern truck, reduce wear on the engine and trans incredably, and reduce fuel consumption. The first two reults imho are where its worth the money. But if you dont have the budget doing all the small things mentioned above will help keep the truck running optimally in its current configuration, ie urning as little fuel as possible
#18
03-10-2018, 09:08 AM
But when they get out of tune, it really drops off a cliff, when it tracks back up from 9 to 17 it will get your attention. Ignition timing and carb jetting will accomplish this. These trucks will never get Festiva mileage but that's not quite the same thing - and there's no reason to simply waste fuel. Out of tune engines dilute crankcase oil & wash out rings or cause cylinder glazing, foul electronic sensors and plug up $$ catalyst, polllute more etc
Even if the very best an engine is capable of on the hwy is 9 mpg (say a big RV) then that's what you want, because it tells you the ignition system and fuel system and everything is operating within tolerance. MPG falling off dramatically is an indication something ain't right.
#19
03-10-2018, 10:17 AM
#20
03-10-2018, 10:27 AM
An aod to fit a 390? Didnt know they had them. Benefit to a gear vendors is that it is just as stout as the c6 he has, if not more so, and you can split each gear to optimize rpm for towing, essentially ending up with a 6 speed auto. Drag racers use the gear vendors in the same way, having a closer ratio box.
And yes if your truck is way out of tune there will be things you can do to improve. I was assuming he had done that like any good ford truck owner! 😀 and was referring to the things mentioned like tail gate headers ignition upgrades etc that were mentioned. As you are still pouring the same amount of fuel into the engine, just becomes a bit more efficient in burning that same amount. If you want to reduce fuel consumption you need to put less into the engine, efi and reducing rpms with o/d are the best way to do that and still provide performance when needed.
And yes if your truck is way out of tune there will be things you can do to improve. I was assuming he had done that like any good ford truck owner! 😀 and was referring to the things mentioned like tail gate headers ignition upgrades etc that were mentioned. As you are still pouring the same amount of fuel into the engine, just becomes a bit more efficient in burning that same amount. If you want to reduce fuel consumption you need to put less into the engine, efi and reducing rpms with o/d are the best way to do that and still provide performance when needed.
#21
03-10-2018, 10:30 AM
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#23
03-10-2018, 12:22 PM
Cargo Master
Also, welcome to FTE!!
#24
03-10-2018, 12:22 PM
#25
03-10-2018, 12:40 PM
Check for the obvious - underinflated tires, sticking brakes. Then look at the engine itself, gearing, transmission. If the engine has good compression; - you did perform a cylinder compression test, right? ... it will respond well to a tuneup. Ignition timing - the distributor curve, and carburetor tuning will pay dividends. Take the time to study up on carburetor theory and operation, rebuild, installation setup and adjustment. All of the manuals are available now for free download. A lot of people think carburetors are bolted on and that's the end of the mystery.
Very few people understand carburetors very well today, probably not very many did back even when they were common. Just a 1/16" of an inch difference in float height can make a big difference in how it runs, or the wrong power valve will waste amazing amounts of fuel, misadjusted idle mixture will completely foul spark plugs etc. Remember you are unlikely to find a shop that can do this stuff today, and even if they can you'd likely balk at what they would have to charge.
#26
03-10-2018, 02:54 PM
If you don't drive the truck on the interstate much, you could go for some 3.50:1 gears and maybe burn less fuel in town.
Or if most of your driving is on the interstate, then some 2.70:1s would probably pick those MPGs up a little. Make sure the carb is at least properly tuned and that the choke opens up as quickly as possible. Air up your tires to the max pressure.
But if I was driving that truck a lot, I would probably look into adapting an AOD or something, and stepping the rearend gears to at least 3.50:1.
Or if most of your driving is on the interstate, then some 2.70:1s would probably pick those MPGs up a little. Make sure the carb is at least properly tuned and that the choke opens up as quickly as possible. Air up your tires to the max pressure.
But if I was driving that truck a lot, I would probably look into adapting an AOD or something, and stepping the rearend gears to at least 3.50:1.
#29
03-10-2018, 07:13 PM
Cargo Master
Alright, you got me a little confused. We need details. Ford didn't have O2 Sensors in the 70s (if they did, that's news to me). Did a previous owner install a throttle body injection or something? Does your truck have an O2 sensor now? If so, please provide a picture. I'm not making fun of any one here. Just sometimes people buy a vehicle and don't really know what they have.