Gas Mileage
 

I have a 1978 F100 with a 302. Right now It has a 2 barrel carb and is 2wd. As far a I know everything looks to be original. What should my mpg be...Also those of you with a 302 are you running a 2 or 4 barrel carb, what size tires do you have, what size gears are you running and what mpg are you getting. I bought this truck for my 16yr daughter and she loves it, now I'm just trying to make it affordable. I drove her truck the other day to work about 50 miles one way all on the hwy, and I got anout 10 mpg, and thats keeping things below 70 mph. I have no idea what gears are in the truck yet....NEED SOME HELP

That's pretty cool that your 16 year old daughter likes these old trucks. My Dad gave me my 79 when I was 15. Now I'm in my early 40's and still drive it to work daily.
Mine also has the 302 and averaged around 14 mpg or so with the original 2 barrel. A couple of years ago I switched to an Edelbrock 600 cfm as well as shorty headers, 3" single exhaust and a Competion cams cam that is just a tick above stock specs.
Looking at the last 4 months, my average is 14.9 mpg. I had a low of 12.7 to a high of 17.1. It all depends on driving style, traffic lights, weather etc. In the winter, fuel mileage goes down 1 or 2 mpg due to the choke being more of a factor in cold temps.
I look at it this way, I gained 1 mpg and gained alot more throttle response and noticable power across the board. And it also got rid of that lean part throttle ping from the lean calibrated 2 barrel.
My truck is also 2WD has a C4 trans, 2.73 rear and 235/65 15 tires.

Im sure a huge issue is the tire size the PO had put 31*10.5*15's on the rear and 255's up front. I will get this corrected soon. Thinking of 235's....I'll have to look at the size diff. between the 235/65 and 235/75

I have a '79, Stock 302, 2bbl, 3spd unsure of gearing. Just put a new set of 235/75's on, and I get 12-13 mpg. Mostly farting around town, but a few interstate jaunts 30 miles roundtrip to make sure theres no carbon buildup :)

-Nathan

Jade, We have only had this truck about 2 week and I can't tell you how many time I have heard men of all ages comment about how cool it is to see a young lady that like the older trucks. Plus it makes it even better as small as she is (5ft and 106lbs). Its really kinda funny to see the look on their face when she can actually talk to then about the truck and understand what they are saying....

How long since the last tune-up? Don't spend too much time looking at tires and gearing if you've got a clogged air filter, gummed up carburetor and fouled plugs.

Lets see. I have a 1975 f100 3 on the tree. 302 with a 3.89 rear gear and 235/75/15 tires. I've gotten a high of 17 before driving highway but averaged 10 to 12 on my original motorcraft carb. But that carb was bad so I just recently swapped to a Holley 2300 2 Barrel and once I got it dialed in I've seen a big increase in mileage about 16 to 17.5 average.

Mike that's pretty damn good. Thats better than my 06. I have cleaned the carb and pulled the plugs and all looks ok

Mike are you still running the factory intake.....would I be better off upgrading it..Not as worried about power as much as mpg for her and most driving will be in the city. Holley has always seemed to be very touchy...

Alright ya'll is there a better replacement intake for a 2 barrel carb, that would be worth the money

Is the truck auto or manual?

[quote=Ken Blythen;10697905]Is the truck auto or manual?[/qu

It's an automatic

I have a 1982 with a 302, C6, 2.75 gears, and a 600 CFM 4bbl Holley. It has 235/75R15 tires. It also has a Performer RPM Intake, unknown aftermarket cam, 1.6 Ratio Erson Roller rocker arms, headers, and is bored (30?) over.

I got the truck last year about a month before I got my license, and I have been fixing minor problems since. I haven't gotten less than 10mpg, and I haven't gotten more than 13mpg., but i'm still working on improving it.

5.0 efi conversion.

Here is the write up of my conversion: The Street Slammer Project EFI conversion

Try plumbing some cooler air to the air cleaner. If you have an open element air filter that draws hot air from under the hood, you can make some mileage gains there. Cooler air makes more horsepower and gives better mileage. 82-85 5.0 Mustangs came with a dual snorkle air cleaners that you could use on your truck and could be plumbed thru the core support or inner fenders.