Actual mpg reports

B

Blairsville Ed

Famous Member
I’m curious as to what others are experiencing in actual mpg. Please indicate the motor, trans, rear axle gear ratio, carb, ignition system.
My first mpg test with my restored 1977 F150 with a mostly stock 300, YF carb, DS2 ignition, C4 trans, 2.72 rear axle, driven for 160 miles on rural 2 lane roads, going from 2000 feet elevation up to 3000 feet down to 800 feet elevation and returned by the same route.
16.5 mpg
 
94 F150 extended cab long bed stock EFI 300 M5OD 5 speed 3.55 rearend, stock tires. Im just above sea level. So far i have only calculated highway, no drastic changes in elevation. Lately ive been fighting my efi system and cooling system not getting up to temp for the efi to go into closed loop. Been averaging about 16.5 mpg but at one point i had it up to 22.5-23 mpg. And i think i can get even more out of it as i have yet to do any mods to reduce parasitic loss ie electric fan, open the exhaust, roller rockers, and maybe a 3.08 gear but 3.55 is actually a good gear if you want slightly bigger tires or economy. Plus my bed is weighted down with about 400ish lbs of tools for work. Im considering getting a 2500-3500 Ram 2006-2007 with the 24v 5.9 to be my work truck and then this truck can be my project truck.
 
83 F100 2wd 300/c6 with 3.50 rear and 29inch tall tires. I get roughly 15.6 driving country roads 30 miles each way to work at about 58-62 mph. I think it should do better than that.
 
InlineDave87 said:
94 F150 extended cab long bed stock EFI 300 M5OD 5 speed 3.55 rearend, stock tires. Im just above sea level. So far i have only calculated highway, no drastic changes in elevation. Lately ive been fighting my efi system and cooling system not getting up to temp for the efi to go into closed loop. Been averaging about 16.5 mpg but at one point i had it up to 22.5-23 mpg. And i think i can get even more out of it as i have yet to do any mods to reduce parasitic loss ie electric fan, open the exhaust, roller rockers, and maybe a 3.08 gear but 3.55 is actually a good gear if you want slightly bigger tires or economy. Plus my bed is weighted down with about 400ish lbs of tools for work. Im considering getting a 2500-3500 Ram 2006-2007 with the 24v 5.9 to be my work truck and then this truck can be my project truck.
Click to expand...
22.5-23 mpg!
That is impressive. I wonder if the M5OD plus EFI is that big of an improvement.
I had a1985 F150 which had a 4speed OD, it probably had the YFA carb that was mixture controlled. I could routinely get 21 mpg with that set up.
Do the Ford C4 and C6 transmissions use a lot of hp?
 
85 E250 about 5000 lbs. 215/85r16 tires. Aod 3.55 gears. Consistent 12.5 mpg mostly highway at 65 mph on 18 mile commute. Stock except computer removed, yf carb, not well curved ds2 on manifold vacuum, cool running junk thermostat. Used to get consistent 14.5 mpg before only change of replacing head gasket to fix minor exhaust leaks, decarbon severely gummed up intake valves, minor bowl blending, and richening Chinese carb to proper afr. Driveability and ability to hold overdrive greatly improved but 2 mpg reduction is disappointing.
 
I used to have a 88 e250. C6, 3.55 gears. When it had an abusive 245,000 miles on it with a broken piston ring and probably a couple leaking reman injectors it got 10-12.5 mpg. When I purchased it with 140k it would get 17mpg on a long highway trip.
 
I get 13mpg in town and 22 highway with my '65 F100.
300, dual efi exhaust manifolds, 9-1 CR, stock cam, HEI distributor, Holley Sniper 1100 single barrel EFI on a stock log intake. And the real reason for the good hiway mileage is the T5 with overdrive. At 70mph, the motor is doing about 1700rpm. Plus, I drive very conservatively.
If you drive like an idiot, you will get idiotic fuel mileage!
 
Our 1988 E150 Econoline did ±17 mpg typically, mixed local and expressway. Bone stock, C6 auto trans, light miles, regular 87 octane. It had a fuel log for the biz, was typically lightly loaded with tools and parts, and little aggressive driving, with only occasional trash or large boat trailering. It averaged 14-16 local, and 18-20 highway (speed limit +5-10). Best highway of 22 at speed limit. Even with a heavy hydraulic lift on the back (and glad we had it for rear weight), it would light the tires up quite easily, sometimes wheelspin was an issue wet or dry.
 
PSIG said:
Our 1988 E150 Econoline did ±17 mpg typically, mixed local and expressway. Bone stock, C6 auto trans, light miles, regular 87 octane. It had a fuel log for the biz, was typically lightly loaded with tools and parts, and little aggressive driving, with only occasional trash or large boat trailering. It averaged 14-16 local, and 18-20 highway (speed limit +5-10). Best highway of 22 at speed limit. Even with a heavy hydraulic lift on the back (and glad we had it for rear weight), it would light the tires up quite easily, sometimes wheelspin was an issue wet or dry.
Click to expand...
Which rear axle ratio do you have?
 
It was an 8.8 axle, and pretty sure it was 3.73s, as we had to replace whining gears at something over 100k miles, and that's what I recall. Stock 30-ish inch tires. Highway rpm was the high 2000s, which was not bothersome when empty, but nice for torque when towing.
 
You must log in or register to reply here.
Back
Top