EFI sucks balls for mileage. Go look at window stickers on new trucks and see. 15-19 is what you see as a general rule. It was the same 40 years ago. EFI ain't sheeot in my book...and that's what those figures are based off of you found. A good sized properly tuned carburetor will win out IMO over EFI. Especially a Thermoquad.