Well since this thread is back among the living, to dovetail into your question about headers, what about a mandrel bent Y pipe with a flowmaster merge collector and stock manifolds? I would think it would give a boost to hp and mpg.

 

I have a 94 Bronco with a bone stock 460, 5.13 gears, 42" tires. 3,000 r.p.m. at freeway speed. 6.2 m.p.g. calculated with g.p.s. I sure can tear up the mud..................

 

Ill play. 97 f350 SCLB, 460, E4OD, 4.10 gears, 235/85R16's, verified speedo, Headman headers, magnaflow cat and straight through muffler all 3 inch, cut air horns, full tune up, HO coil, adj FPR set at 42psi, and insulated intake (see 'project MPG').

Winter ~5.5-6 mpg. Spring/summer/fall ~8.5 mpg. Just about all city miles.

2 notes. It a 4 mile drive to work 1 way. Starting the engine to worm up in the winter almost double the amount of time the engine is running. This I belive is the reason for the wide range between seasons. Also, I believe my Magnaflow cat is too small for the engine and thus choking it out a bit. This may also compound a slightly below average mileage for the truck.

 

I'll post this in the "Thread that will not die".

1997 F250HD 4X4 Reg cab, 460/E4OD/4.10 gears. 235/85-16 Wrangler Duratracs. No engine mods and the exhaust is stock, as far as I know. I also have a Drake Welding rack on my truck that I know kills mileage.

I get 7 to 8 mpg in town and 11-ish on the freeway with the speed control on. Town mileage is influenced by traffic, since I have to drive past five schools on the way to work. My total work commute is in town, by the way.

Ray

 

Yea, I know it says don't laugh, but......pfffffttt..ha..hahaaaa...haahaahaahaaaaa. .........

 

Other than engine oil choice, nothing seems to be more fascinating than the gas mileage attributes of a Ford 460. It has been almost 11 years since I first posted to this thread. I still have that truck and it gets the same mileage it always has. It is a keeper for sure. I will update in a few years when someone else digs this treasure of a thread up again.

 

With that truck don't expect much over 8 most automatic 460's have 4.10's ...... I looked and did my homework before I found my 460 5speed with 3.55 much better combination I get 13 no matter what I'm doing but this truck has headers which is a big improvement actually lets the engine breath. I would hold out for a 3.55 gear ratio auto if you can find one I know they are out there but are few and far between. That's just my 2 cents.

 

I've got the 4.10 rear, but it runs like it's got the 3.55 because I've got the 39" Mickeys. Remember you can change the gearing by increasing the tire diameter, and it's a whole lot easier than changing gears........

 

OK I'll chime in.
For those who might be interested, motor home chassis 460 efi, c6, 3.55 gears and 16" tires. Pushing 10,000 pounds down the highway , I get around 7mpg, best I got was 8.5mpg.

I think I can see the fuel moving going down the road.
Not complaining , just acknowledging.

 

Okay, resurrect again 1989 Ford F350 EFI, running in limp mode I get 12.5MPG highway consistently (when not towing), 4.56 gears and E4OD auto. Start towing and you can literally watch the gas gauge drop...

What I really want to see is a turbo 460...

 

96 crewcab F350 540 5speed 3.55 gears and all stock but 33" tires. 13mpg Hwy
10 "city"

same truck with bandk torque tubes(headers), hi flo cat, 3" mandrel bent exhaust and 20 series flow master, BBK throttle body, timing advanced to 12*, Vortech S/C and 325/65/18(35x13.50) tires

12mpg hwy , 6Mpg "city" , but now it will blow the doors off almost ANYTHING on the road

 

DB, which Vortec did you use?

 

I might have most beat (for the worst that is)!

1978 F150 RCLB 4-spd 4x4. 460 bored .030 over, forged pistons, torque cam, Edelbrock intake and 750cfm carb. 4.10 gears and 35's.

I don't drive on the highway with this truck, but just back country roads and the outskirts of town. I get about 4-5mpg...

 

The SQ head unit. It was the only one offered as a kit when they were available

 

I just joined the forum, but I swear I must have looked at this thread a dozen times over the last several years searching for anything to save money on gas for my f350. lol $100 fill ups cause you to stay up till all hours of the night plotting your next modifications, and it always leads me back here