I have a 91 civic std with a ls (b18b1) in it. All thats done to the motor is advanced timing, intake, header, and thats it. I got a S1 ls tranny with no 3rd or 4th gear, act 6 puck hd clutch. I went to go fill up, and i calculated and got 20mpg. Is it because of the tranny or am i running real rich cuz i got no o2 sensor, and the advanced timing. I am going to rebuild my tranny just saving up.

 

why do you not have 3rd or 4th gear?

 

Because some guy lied to me saying the tranny was good. Hate people like that.

 

ah ok, the trans itself will defiantly make a difference. loss of 3rd and 4th will reduce gas mileage because you are using rpms and more throttle to compensate.

im sure the other gears "3and4" are still inside your transmission in pieces that are not helping either.

 

Yea, im thinking of rebuilding it but thats a lot of money, but also thinking buying a used one from someone, only thing is that i am taking a risk.