trying to improve fuel economy looking for any ideas

[okiebronco]

you could always put a 6banger in there for better gas milage lol j/k but seriously tho the better the engine beaks and exhales the better the milage will be

[Paarrothead]

Here's the article someone mentioned documenting mods on an EFI 460:

http://performanceunlimited.com/projectmpg/results.html

I get about 11.5 with mine, 50-50 mix of highway and town driving, 7 to 8 when I'm towing a loaded flatbed or our horse trailer (it's tall, lots of wind resistance!)

Headers and exhaust got me about 1/2 MPG, switching lubes- to Mobil 1 synthetic 10W-30 in engine, Redline synthetic D4 ATF in tranny and synthetic in axle got me another 1/2 MPG, advancing the timing as much as possible, improving the cold air intake AND burning regular got me another small improvement. Blocking the EGR made the engine ping and run awful, I put it back. Changing the catalytic made no mileage difference at all.
So I got maybe 1-1/2 MPG improvement total with bolt-on mods- Hey, that's 15%!

Even though I've got a fancy new PSD, I still love that 460. Comfortable, reliable, smooth, and it hauls @ss. I'm going to keep it forever.

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2002 F-250 S/Cab Short Bed PSD 4x4. SCMT +80 HP, AFE Magnum intake.
1996 F-250 S/Cab Long Bed 460. E4OD auto, 4.10 posi, Air-Lift suspension, K&N filter in modified intake box, modified ignition advance curve, Edelbrock 2x61 mm throttle body, L&L 4 into 1 headers, slightly milled heads, 3" exhaust system, cat & Flowmaster 70, modified MAF meter. 7,700 lbs GVW, 5,700 lbs empty. {E\...F}

[mgm5555]

ok went though some semsors, found that the act was bad but the ect was good. still have to check the MAP and see if the O2 is sweeping. also have to figure out the egr arrangement.

I was thinking since i am down 3.5 to 4 MPG's it must be something else like a gas leak. I did lots of checking did not find any gas leaks.

will check MAP, fuel pressure, egr after that maybe this truck only got 8 mpgs

would anyone know the on time of the fuel injectors? I could measure and see if it close, say at idle? maybe 20Msec

with the price of gas its costing me about 25 cents a mile little to rich for me.. but i like this truck, oh well.

keep the ideas coming

[74crwcb429hibPS4spd]

Check your alignment it makes a big big difference.

I run between 12 to 15 MPG with my rig. I have checked the MPG many times in the last month. I have set my Idle speed to about 650. Runs a little ruff when cold.

I have 235/75/R16 skins and 5.13 gears, 4 spd trans, devorced NP205. I rarely go over 60 MPH with the 5.13 gears. I am thinking of changing my gears to 3.54 for freeway 70MPH+ reasons.

Greg

[DPW]

(This is why I like carburetors), just a thought, if you knocked out the cat, how can the o2 sensors sense enough heat to lean out?

[jbalestri]

Whether or not you have cats, and whether or not you have gutted cats does not affect the O2.

The exhaust gases are atleast 600* coming out of the head, and that is what heats up the O2.

Headers can reach temps of 1000* in race cars with open exhaust systems. The O2 is typically placed between downstream of the exhaust manifold, before the cat. Even if it was after the cat, the exhaust system gets sufficiently hot enough.

[mgm5555]

yes i tjink you may be right, but sensor does come up to . 5 volts which tells me its hot enough, as well as it a three wire so its self heating. the cat was clogged which means motor was running rich.