Super Six fuel mileage

Well, here's a reply a bit outside the bounds of this topic, but: I've got a 318 w/ a 4spd Mnl in a BCuda Convertible. When I first got the car, I drove it for about 100 miles on I-85 @ abt 60-65mph & got approx 23mpg. That seemed really ridiculously high for this setup, but it seemed to work out. Also, this car had a points ignition & a 4bbl Holley (maybe abt 500cfm - forgot the model #, but it was a smaller 4bbl).

Oh yeah, also the 318 is out of a 1985-86 Fifth Avenue, so it has the newer heads, also good for 'newer' gas.

Later, I changed to electronic ignition & carb to a new Thermoquad. Most of the driving has been City, so the mpg has been around 13-15mpg. I admit that I am not the best at tuning. Nonetheless, a recent Freeway drive for about 200miles again seemed to get me in the 20-23mpg neighnborhood.

I'll admit that a sizable margin of error is possible. But, it seems that a V8 is capable of 15-20mpg if dialed right. I think that that dialing-in might be a bit of luck, but I think my theory that a higher displacement engine that is run at lower capacity (i.e a V8 revving lower than a /6 or 4cyl) can give some decent mpg.

With that in mind, I've always wanted to soup-up a /6 for performance & economy - seems like a lot of potential w/ these motors.