I'm just curious if it's worth doing. I have an m3 running around 20mpg stock, but after I added intake and full exhaust..it went up to 25mpg..which was great. Any idea?

 

Why don't you just drive your M3?

Integra's are great but an M3...

 

My civic is my beat up vehical. I drive it to work since I have to leave it unattended. Come to think of it...the GSR does have crappy milage. I get better milage on my I6 333 hp than a I4 170 hp.

 

1) you have to rev the piss out of the B18C1 to get moving
2) have you done the routine maitanence? (fuel filter, plugs, wires, rotor, cap)
3) 2 COMPLETELY different cars

intake & header for better mpg? hm...maybe 1 or 2, but the sound of intake will make you keep flooring it.

 

This is a newly swap. I had the fuel filter, spark plugs, water pump, oil pump, timing belt replaced. I don't know about rotor and cap...does that matter with a 40k mile car? Should I do another oil change at 500 miles on the new engine? The only part of the exhaust system that I haven't replaced is the header. Is the OEM header really constrictive? BTW, I filled up my gas yesterday and noticed I've got 24 mpg. I want to get near 30 if possible.