better MPG

[jwilson13b]

Its been a long time since i have messed around with timing. Im lookin for better mileage outta my 318 in my power wagon 4x4. I remember someone telling me backing it off a degree or two from factory will improve mileage, while bumping it forward will improve power. True, false, or oppisite
thanks.

every penny i can save on my other modes of transportation meens more money for the duster.

 

[C130 Chief]

Advance for mileage.

Trucks are aerodynamically bricks, slow down for MPG.

Are you running the stock carb?

 

[jwilson13b]

yeah, running the thermoquad. but im switching to a holley 450 vacum secondary. And i drive it a 55 on the highway

 

[rumblefish360]

IMO, the T-Q is best for mileage, but a fine tuning may be difficult to do since parts are very hard to come by.

My best mileage adder was a Jacobs Pro Street ignition, you'll do just fine with a MSD set up. Open air filter and a K&N or equal will be good to do. Headers with a 2-1/4 inch pipe and a cross over. H or X with performance mufflers. If you need to have cats on the truck, dual cats near the collector of the header. Deleate A/c if possible, electric fan A better intake than stock, a Edel. Performer would do well.

etc.......

 

[MopaR&D]

With a truck it'll be tough to get noticeable improvements in gas mileage. What rumblefish recommended is good, along with a properly set advance curve. More advance will give you more power AND mileage (improves overall efficiency of the engine), but to an extent, of course. Set initial around 10-12* advanced with about 34* total around 2600 RPM. Also make sure you're running as much vacuum advance as possible without running into ping at cruising speeds.