One big issue barely mentioned previously is aerodynamic resistance, or more accurately poor aerodynamics. A flat vertical windshield, fenders that act as big scoops, flat front grille, and more all contribute to lower mileage. Yes the engine should be checked for max efficiency and running at good high vacuum. Low vacuum means using heavier throttle. It's going to take a lot more power going faster. That applies to any vehicle.
So now that we morphed into the price of gas, my add on to that is who gives a shit. Add more mileage you can go further between stops and save time. Here's an old one I shared before. My tinker neighbor said he bought this wazoo carb that promised 50% more mileage. Then he got this hopped up ign system that promised 30% better fuel mileage. Then he got one of those spin Dixie swirly air cleaners for another 25% better fuel economy. Put it all on one day and his damn gas tank overflowed.
The Jalopy Journal
