Miles per gallon?

[duaneo]

Folks,

My less than 500 mile 360 isn't running super well, the carb needs some tuning, and maybe a rebuild, but I'm wondering what kind of miles per gallon I could hope for. Currently I'm at 8.9 MPG.

I've got a C6 trans, 360 FE, stock cam, stock heads, original boat anchor intake manifold, stock exhaust manifolds, and a 2bbl 2100 motorcraft carb.

What are you running, and how many mils per gallon are you getting?

Thanks,
Duane

[Kurt Combs]

When my 1972 F-250 two wheel drive had that exact engine, it got 13 MPG on the highway. To check the mileage I would fill it up and drive it from Lake County to a destination such as Chico or Sacramento, all highway at speeds of 60-65 miles per hour, and then refill at the destination. That was my cruising speed MPG. I didn't bother to check the mileage when driving around town.

[1972hiboy]

my highboy has a 390 with rv cam, performer intake generic holley vac secondary carb. np435 and 4;11'sif I drive responsibly empty I can see the 13mpg range. truck usually has my camper on it. last trip I took a couple weeks ago with the camper laoded to the gill I got a solid 10mpg. i have had worst with this setup but depends on cruising rpm. once I get past that sweet spot the mpg get sacrificed for speed.

[HIO Silver]

Folks,

My less than 500 mile 360 isn't running super well, the carb needs some tuning, and maybe a rebuild, but I'm wondering what kind of miles per gallon I could hope for. Currently I'm at 8.9 MPG.

I've got a C6 trans, 360 FE, stock cam, stock heads, original boat anchor intake manifold, stock exhaust manifolds, and a 2bbl 2100 motorcraft carb.

What are you running, and how many miles per gallon are you getting?

8.9 MPG what? Highway, city, or combined?

My brother's 69 F100 longbed with the same combo as yours with 3.25 rear gears managed 15.6 MPG (highway) from the Bay Area to San Diego. Cruising speed was 60-65 MPH.

[duaneo]

That's commute driving. I've hit the 500 mile mark on the new engine, so I'm planning on parking it for a bit and doing some additional work. A carb rebuild to begin with.

It will stall if I'm not gentle enough off the line, and it feels like I'm pulling a parachute behind me if I floor it in the midrange. Hopefully a carb rebuild plus a good tuneup will address these issues and get it running perfectly. THEN we'll see what kind of mileage we get.

Cheers,
Duane

[Mancar1]

I have had a few of these old trucks with the FEs and I seem to ave around 10MPG on them all. I sure don't have them for MPG.

[6Delta]

Folks,

My less than 500 mile 360 isn't running super well, the carb needs some tuning, and maybe a rebuild, but I'm wondering what kind of miles per gallon I could hope for. Currently I'm at 8.9 MPG.

I've got a C6 trans, 360 FE, stock cam, stock heads, original boat anchor intake manifold, stock exhaust manifolds, and a 2bbl 2100 motorcraft carb.

What are you running, and how many mils per gallon are you getting?

Thanks,
Duane

Rebuild the carb yourself and CLEAN every passage, it is not rocket science but requires thought. I soak mine overnight in 5 gallons of Berrymans (sp?) then blow every passage with high pressure air. Set it up right according to the kit. Then look at your timing (i.e.) distributor. If it has points, go to Pertonix or something close to the same. Otherwise set the DWELL, not the gap. Lastly tune with a vacuum gauge. Do not rely on setting timing and points by the book specs. Do a little research and you will find it is not that hard. Lastly, what is your, to the road, gear ratio. (35 inch tires with a 3:00 ratio will never get great mileage, nor will 28 inch tires and 3:50 gears.)
Everything works together. With a decent size tire and gears with a well tuned engine, I would expect to get 15 mgp at least, with hard work you may get close to 20 on the highway, if you can drive like my son. Add a 3:50 rear gear and you get closer to 13-10. I had a 74 351 Windsor out of a Torino Elite with the FMX and a 3:00 gear in a 64 1/2 ton. A straight swap except for the fact that in 1978 I was not sold on electronic ignition so I went with points. Also I added a Offy 360 with a 2v adapter (I still went with the 2100 carb). I could count on 17 mpg on the highway with a full load. Around town, not so good. My present 71 F250 with a 360, 3:73 gears, headers, Holley Dominator, Edelbrock 1406 and 2 1/5" exhaust gets only 8-10. I It goes quick, just not fast. My 64 would top over 120. I don't want to wind my 71 up to see what ot tops out at.

[duaneo]

This is a very complete and helpful answer - not that the others weren't - thanks for the input! I'm looking into a points upgrade now.

Cheers,
Duane

[colnago]

I have a '67 with a 352. The PO installed a 4bbl intake and Edelbrock carb. In town, I get 9.5-ish. I have two cylinders with burnt valves, though, so I can only drive about 20 miles before it starts pinging.

Joseph

[rwilly]

I am getting 9MPG out of my 69 1ton with a 360. I use it to haul firewood, dumploads, gravel, etc. Just for my own personal use, I only drive it once a month or so.

[Pat Crash]

Pretty much stock 360 with Pertronix, Autolite 2100, stock intake. Tuned by multiple mechanics. Combined — 8 miles per gallon, 9.3 was my best reading. Drives me crazy trying to improve it. Many people on this forum have had the same experience and it is difficult to understand how others with basically the same setup can get 12-13 mpg. I drive pretty slow on the freeway (55-62mph) and try to take it easy on the city streets. These trucks would be perfect if not for the poor gas mileage.

[tqwrench]

I knew what I was getting into with a 390 in my truck. Christmas cards from OPEC thanking me for my business.

Once I get my speedometer issues resolved, I want to run a baseline fuel economy (truck is bone stock tuned to factory specs). Then I'm planning an experiment with a 2700 VV. It was a popular modification by some tech's in the 80s to wring a few MPGs out of their trucks. The VV carb was reviled by many. Those who knew how to set them up and keep them up could make them run well.

I mentioned a VV to an old tech and he forked his fingers over his eyes and spit on the ground. Parts manager smiled and said he made a fortune off them and selling Motorcraft 2100s to replace them. Sort of like the Caddy guys and the HT4100 engine, they paid their houses off on those things.

[radioactivelarry]

I knew what I was getting into with a 390 in my truck. Christmas cards from OPEC thanking me for my business.

Once I get my speedometer issues resolved, I want to run a baseline fuel economy (truck is bone stock tuned to factory specs). Then I'm planning an experiment with a 2700 VV. It was a popular modification by some tech's in the 80s to wring a few MPGs out of their trucks. The VV carb was reviled by many. Those who knew how to set them up and keep them up could make them run well.

I mentioned a VV to an old tech and he forked his fingers over his eyes and spit on the ground. Parts manager smiled and said he made a fortune off them and selling Motorcraft 2100s to replace them. Sort of like the Caddy guys and the HT4100 engine, they paid their houses off on those things.

I remember back in the day the VV carbs could get exceptional mileage if you set them up for that. I read many articles in the magazines like Mother Earth News back then. If you could find those articles you could see how to tune one. Claims are Ford quit making them for that reason..........

[tqwrench]

So far, $$ wise this is a no-brainer. I got the original Rotunda tools to set the carb up for $9 - hell the manometer itself is worth a decent buck, and a used carb off a 351W for about $40, then a rebuild kit for $25. Should be fun. I'll look for those articles you mentioned and see what comes up.

[hedz]

i'm getting about 15 mpg in 3rd gear going 60mph. any faster and the mpg goes dooooooooown. 360 with 3 speed on the column. got iridium tip plugs, hei dui, dui wires, cast iron 4 bbl intake, 4 barrel holley 4100. plugs gapped to about .75 i think. hei dui makes something that is put inline in the ignition somehow to increase spark so that the plugs can be gapped even larger to help burn fuel more efficiently.

fordification needs to band together to 3d print a plastic air gap quadrajet intake. i'd buy one.

and i think that a 390 with fuel injection and mike holler porting technique and valve mods with a turbo at light boost backed by a 5 speed and a highway gear could get well over 20mpg

and what about gas vapor? i keep seeing articles and videos on aerating gas to a vapor to increase mpg. i'm sure it's possible. i mean wtf would pogues carburetor be in a museum if it wasn't something?

and then there are those 4 barrel and 2 barrel carb plates with propellers inside of them and a air injection port on the side that help disperse fuel into smaller droplets for better atomization before hitting the combustion chamber that have been documented to increase horsepower and mpg that were discontinued back in the 80s. i've seen pics of these on old gear heads collections. i wonder if the circle holler porting technique works against atomized or vapor fuel or if it's better with liquids... i love theorizing and talking about this stuff.