Have a noob question guys. Bought my wife a cherry Civic DX hatchback with the TBI 1.5. It's manual everything and gets phenomenal gas mileage, like 40s on the highway, but it screams on the highway because it's got a 4 speed manual, pretty funny when we test drove it and I went for 5th gear. Is there a 5 or 6 speed that will bolt up to this car with minimal modification and give me a final ratio more suitable for long distance travel? I ask because we're being gifted a van for my wife's work and my trip car is the logical one to let go so we don't have 5 vehicles.
I'm a mechanic/masters degree student by trade so the greasy part is no worry, I just have swap knowledge. I just know how to keep them running. Thanks in advance for the help.
Rob

 

any 89-91 CRX/Civic 5 speed transmission will bolt right in using your existing shift linkage - you have a 91, correct? - the DX transmission would probably be your best bet

 

Yeah, it's a 91. There's no problem with the 4 speed, I just want some lower rpms on the highway but I'm one of those 200k mile plus car guys so I don't want to sacrifice reliability. I'm gunning for reliability and fuel economy over speed and power.

 

Any D series 5 speed from the 88-91 years will bolt up. The DX/Si 5 speed is a common swap. You could also swap in a CRX HF 5 speed, that thing has crazy low gears. You might have to bump up the power a little to make 5th gear useable, not sure on that. Hopefully someone else will chime in on this because I've thought about swapping the HF 5th gear into my Si trans for lower hwy rpms.