more exhaust ?'s...
Lead Driver
Joined: Jan 2003
Posts: 9,893
Likes: 12
From: Ohio
Fill up every Monday....I now go 8 days.............
WOW, geez, sure wish I could go that far on a tank. Every THIRD day for me. Course I travel on the average 50 miles per day. That doesn't include any side trips.
Larry
WOW, geez, sure wish I could go that far on a tank. Every THIRD day for me. Course I travel on the average 50 miles per day. That doesn't include any side trips.
Larry
Post Fiend
Joined: Jun 2003
Posts: 8,209
Likes: 12
From: Black Hills of SD
I put headers on a bone stock 74 360 once and gained about 1 1/2 mpg and a considerable notice in power. With stock system it would top out at 85mph with 4.10 gears. With the headers it would twist the speedo way past 100
Thread Starter
|
Elder User
Joined: Mar 2003
Posts: 541
Likes: 1
From: Phoenix Az, by way of Fre
Originally posted by Freightrain
Fill up every Monday....I now go 8 days.............
WOW, geez, sure wish I could go that far on a tank. Every THIRD day for me. Course I travel on the average 50 miles per day. That doesn't include any side trips.
Larry
Fill up every Monday....I now go 8 days.............
WOW, geez, sure wish I could go that far on a tank. Every THIRD day for me. Course I travel on the average 50 miles per day. That doesn't include any side trips.
Larry
Originally posted by willowbilly3
I put headers on a bone stock 74 360 once and gained about 1 1/2 mpg and a considerable notice in power. With stock system it would top out at 85mph with 4.10 gears. With the headers it would twist the speedo way past 100
I put headers on a bone stock 74 360 once and gained about 1 1/2 mpg and a considerable notice in power. With stock system it would top out at 85mph with 4.10 gears. With the headers it would twist the speedo way past 100
Senior User
Joined: Aug 2001
Posts: 212
Likes: 0
From: Wimberley, TX
I'm getting 15 with just the headers and dual exhaust. I just put in a Pertronix II yesterday and tommorrow I'll be taking a trip and checking my mileage to see if it helps the MPG. I can tell it has helped in the pep dept.
Post Fiend
Joined: Jun 2003
Posts: 8,209
Likes: 12
From: Black Hills of SD
The 74 I referred to was a highboy and I did squeek over 15mpg out of it a few times. If a 3/4 ton 4x4 with 4.10 gears can do that, I would think a lighter pickup with better aerodynamics and higher gears could. One of the problems with mileage on these pickups is the speed. You just can't get decent mileage driving 70-75. If you want better mileage then slow down. Even the 300-6 mileage falls off bad after 60 or so. I have had a few 300s that would run close to 20 at 55 mph and at 65 they would be down around 16.
Take the service roads and enjoy the scenery.
Take the service roads and enjoy the scenery.
Lead Driver
Joined: Jan 2003
Posts: 9,893
Likes: 12
From: Ohio
That's the WHOLE problem, too much gear and twistin' it tight to run with all the rest of the traffic.
If you drive it sanely and keep the r's down it will definitely pick up mileage.
Heck even my 428/4 spd/4.56 gears will knock down 10 mpg if you cruise it slow enough(55 or so). Now, if you get in a bit of a hurry and run it 65-70....5 mpg. Them TWO holleys sure do like the fuel.
Larry
If you drive it sanely and keep the r's down it will definitely pick up mileage.
Heck even my 428/4 spd/4.56 gears will knock down 10 mpg if you cruise it slow enough(55 or so). Now, if you get in a bit of a hurry and run it 65-70....5 mpg. Them TWO holleys sure do like the fuel.
Larry
Elder User
Joined: Oct 2003
Posts: 702
Likes: 0
From: kingman az
fuel mileage
my 71 f250 stepside light duty 6100 gvw with a 390 and with 2bbl and t18 trans and 3.73 dana 60 locker gets the same at 55or 75 in new mexico where i live there arent very many service roads and if you go 55 or 60 on the interstate where the speed limit is 75 the state police will make you go 50 miles out of the way to get where you want to go .the best mileage i got before the 390 went south was 6 and with a 19 gal fuel tank you cant go far
Post Fiend
Joined: Jun 2003
Posts: 8,209
Likes: 12
From: Black Hills of SD
Ird56 if you can only get 6 mpg out of a 390 2bbl. at 55 mph you have something seriosly wrong with your whole set up.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
Elder User
Joined: Oct 2003
Posts: 702
Likes: 0
From: kingman az
fuel mileage
my f250 got a rebuilt 390 in 78 and right away it got bad mileage it used to get 9 the 390 is a fred jones remand motor from oklahoma city i will never buy another one thats why i want to put in the 330xd and allison auto out of my bus the bus weighs 11000pounds and gets 8mpg at 65 so i figure my truck with the 330xd and the allison auto should weigh about 5000pounds so i should get better than 9mpg
Post Fiend
Joined: Jun 2003
Posts: 8,209
Likes: 12
From: Black Hills of SD
I think most of the over the counter rebuilds are questionable at best. I have seen plenty of them that didn't make it very far. I have seen engines that just weren't efficient too. I had a friend that had a new chevy 1/2 ton 4x4 that would only get 4 mpg. He had it back to the dealer a few times and finally traded it off. I also new of two guys that bought identical 1/2 ton chevys in 1970. One pickup would get almost 20 and the other about half that. They even switched and it made no difference.
I used to get alot better mileage back in the 70s and early 80s than most of you guys now seem to get amd I have to wonder if the formulation of gasoline nowdays has anything to do with that. I have had plenty of pickups with FE motors back then and never got less than 10 and got as high as 15 out of some.
I used to get alot better mileage back in the 70s and early 80s than most of you guys now seem to get amd I have to wonder if the formulation of gasoline nowdays has anything to do with that. I have had plenty of pickups with FE motors back then and never got less than 10 and got as high as 15 out of some.
Thread Starter
|
Elder User
Joined: Mar 2003
Posts: 541
Likes: 1
From: Phoenix Az, by way of Fre
Originally posted by 8NRay
I'm getting 15 with just the headers and dual exhaust. I just put in a Pertronix II yesterday and tommorrow I'll be taking a trip and checking my mileage to see if it helps the MPG. I can tell it has helped in the pep dept.
I'm getting 15 with just the headers and dual exhaust. I just put in a Pertronix II yesterday and tommorrow I'll be taking a trip and checking my mileage to see if it helps the MPG. I can tell it has helped in the pep dept.
Do you know what headers you're running?
Senior User
Joined: Aug 2001
Posts: 212
Likes: 0
From: Wimberley, TX
Well it was 14.8 after adding the PII ignition so far I can't say it's made a difference in MPG. I'm going to set the plugs to .040 and try again. I running Hedman headers.
I really like the Pertronix. Easy to install.
I really like the Pertronix. Easy to install.
Senior User
Joined: Dec 2002
Posts: 168
Likes: 0
From: Omaha USA
I am running the Dynomax on my truck and had to ream out one hole on the drivers side for the bolts to line up but fit nice otherwise. I had duals ran all the way out the back with flowmaster 40's. It is not that loud in the cab but when you get around the back,,,,WOW!!! Almost sounds like open headers. I tend to agree that glasspacks are too crackly and regular turbos are too constrictive. Flowmaster or their equivalent are the only way to go for low backpressure and getting the exhaust out of the FE motor which is cursed with too small of exhaust valves.
Thread
Thread Starter
Forum
Replies
Last Post