Lots of engines will give that mileage but he has the three mentioned. Two V8's and a straight 6. The 265 mileage is lower than the 235 and 350 and may not achieve 18-19MPG like the other two. All gearing the same. etc., after reading some original mileages given, I have to say the 235 is the most likely and the 265 is the least likely to get there. The newer V8's get past 20. That's technology for ya. Remember, gas mileage is almost the most "exaggerated" subject there is on the planet.

Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn