Being concerned with fuel mileage is normally going to be a reduction in gears, converter and cam. The best way I have found to bridge the gap between the two is to use an OD trans. IMO, the automatic, 904 or 727 based transmissions, are the best bet here as a cheaper MoPar 4spd-OD has a big gear split which some find distasteful & the final drive isn’t on the main shaft, it’s where 3rd gear is in normal 4spds. And also the bell housing is a huge PIA to come by.
The thing to do with the engine is still a mild camshaft but what a lot of guys don’t seem to get is 99% of the off the shelf cams are not that good for what there seeking.
A few things you want in your camshaft is a narrow LSA for the engine size and then a quick lifting valve as high as possible. This needs to be coupled with a high flowing head! Most people just get a cylinder head and slap it on OOTB and go. The heads in most cases should be ported.
In the case of the trick flow heads, there really hood flowing OOTB.
Yes this is expensive! It is worth the power return since it will do so reliably over and over again. The cam you using with this should lift the valves as much, at the least (IMO) to take advantage of the cylinder heads port flow abilities.
Most will also not investigate or spend the money on the best power adder available and that would be a super charger or a turbo. Besides the expensive, there’s more to it than just getting one and slapping it on and go!
Fuel and ignition requirements are also expensive.
(And a little bit of a PIA to instal.)
A mild cammed engine with excellent heads will work really well and the addition of a super charger doesn’t drink more gas until that peddle is well depressed downwards. Believe it or not, the centrifugal super charger can add mileage since at low rpm’s there is little to no boost but it is still pushing air in helpful if the engine to breath easier. Since it is doing that easier, power is freed up and less fuel is needed to keep things rolling.
I agree, mostly. The people I know concerned with mileage are not looking for 20+ out of there rides but a more reasonable 16-17 mpg. I really don’t think that’s out of line. This should be possible with your first two mentions. Not so much the strip car LMAO! We don’t care there. There really is only one goal.
Of course a street strip car can get less per gallon. A lot depends on how radical that build is. I do t see a lot of mileage out of a 4.56 geared rear and a cam of 260@050 getting good mileage. Hot Street & Street/strip is pretty subjective.