Ok so I need some advice 1989 honda civic d15 b2 300k on motor laster owner blew a head gasket had head redone and shaved done . Runs good Has short ram cold air intake new spark plugs and wires Has two batterys right now Just door speakers no ac or any lines for it. Right now city I get 30 and highway is better. I want to see if I can get any better mpg The only thing I can think of is get a new dissy for it maybe that will make the timing better nad help out some. I'm wanting to get the best fuel economy right now since my job is going to be like 60 miles a day there and back but I will be making good money starting out at 16 bucks . I want to put ac in I have everything I need but I know that will kill my hp and my mpg . Just asking what you all think I should so . Mpfi is in the future but from what I have heard the mpg will go down when I do that. Just asking what you all think I should do.