For the most part you wanna stay in max bsfc and produce the lowest horsepower needed to propel the car at x speed.. The civic was between 1750-2150 max output per g of fuel. Even the LS1 is something like 36% efficient at 2000 rpm at 70 mph which is fantastic and why like half the ls1 cars get 30 mpg on the interstate with their 0.50 6th gears. Even the new c7 corvette went more extreme and went to a 0.40 7th speed. But yeah you can always shift down. With the civic if I went to 4th it brought the rpms up to like 3000 and you could pass like how you used to.
For the most part most 4 cylinder cars have aaaabout the same bsfc chart. Look up the thread on here to make your decision. I mean if your towing a trailer it will make a big difference. But if you aren't.... wind a gear out a lil longer.
I feel like this is the ranger club. I also had a two rangers. 99 4.0 towing pack. 06 3.0. etc...
