Gas Mileage...

[Slomar]

I get 10.7 MPG, 87 octane... the specs

76 F250 4x4

Edlebrock 1406, with 400m and Comp Cam.

33sx12.5, standard exhaust, and mostly freeway driving

3200rpm 4th gear 65 mph.

So who gets more? Less? Tricks? The mileage thread in the main forums covers a lot, but its too general. I was thinking about getting an overdrive, and droping the RPMs to about 1800 at 65.

 

[BlackFord77]

Obviously dropping R.P.M. will increase gas mileage, but on the other side it will be harder on the engine (called "lugging" it), and increase wear on engine parts- so be gentle in how far you drop the R.P.M. . Also the cam greatly affects gas milage. There is no trick to get great gas milage with a large motor without an extra speed in your transmission. You would just end up leaning your fuel mix and burning motor parts over time. The trick is to stick in a small motor and harness maximum power without boring the cylinders (making it a bigger motor anyhow). Of course there are little things you can do to drop weight and increase mileage a slight bit like removing unnecessary parts (weight reduction), tightening steering/suspension components and keeping your wheels balanced and aligned, belly pans (to smooth out air flow underneath and reduce drag), spoilers, and other things like dual exhaust (to cut back pressure and reduce engine internal pressure strains). And don't forget to drop those antique fuel pumps and replace them with electric (outside the tank) to pick up some HP and mileage (use a block-off plate and take the pump off the motor). I'm sure there's more I missed that might do small wonders.

 

[mockdaddy]

Well i have a couple of questions as far as specs. what is the rpm range of the cam? Is the carb adjusted correctly? Stock ignition - points or electronic?
Full time or part time 4wd?

As far as overdrives go I have one in my 78. has not had a big improvement on gas mileage but the engine isn't screaming at hiway speeds. mine turns 2100 rpm at 65 mph and there isn't any risk of lugging.

My gas mileage is 13-14 mpg on highway
33" tires 4.10 rearend
460 .030 over 13 to 1 compression
comp 282 cam and edlebrock 1406 carb.

going to be adding TBI this winter and hope for a few more miles per gallon