I hate to say but the my engine has a slight rod knock. I bought the car used with high miles so I'm wanting to remove the 105 hp original 1.5 16 valve engine, and replace it with the 70 hp, 8 valve CX motor out of a 95 honda civic CX hatchback.

Do I also need to swap the computer from the 95 CX to run in my 93 DX, or will my computer in my 93 DX run the 95 CX motor?

Are the 5 speed transmissions the same in both the cars?


What kind of mpg would I expect from doing this swap? I know I would lose horsepower. I mainly drove the car to save gas in the first place. Thanks in advance! The honda community has helped me every time I've had problems honda related, I just want to thank everyone for the input and help!

 

grab the ECU yes all d-series trans are cross-compatible. look it up cmon it's a quick Google search "civic vx mpg".

 

I fixed it for you. Thanks for the quick reply.

 

Not sure if you will notice much mpg variance between the 102 hp D15B7 motor and the 70 hp D15B8 motor if you keep your DX transmission. I'm currently averaging around 38 mpg during summer on my B7 with a DX tranny. I was closer to 40 mpg with the cx tranny, and that's with a spirited foot quite often.

You will see about a 2-3 mpg difference just by swapping the transmissions. I put a DX 5 speed into my CX thinking my ISB was bad only to find out it's fine and so far that's been the difference on my B7 motor.

That's of course assuming it's truly a CX transmission. No way to identify that just by looking at it, you have to spin the input shaft while the tranny is in reverse and watching the differential do one full turn. Depending on how many turns of the input shaft for one full revolution of the differential will tell you which tranny it is.

The CX tranny has a taller gear ratio than the DX but not majorly. The quickness to get up to speed difference is not very noticeable between the two trannys. The EX or SI on the other hand lays it down much more noticeably but at the cost of top speed and fuel economy and they have a case stamp of B000 while the CX/DX trannys have A000 case stamps.

I think the most gains for MPG would be the B8 motor with the CX tranny and a light foot. But it will be gutless going up hills. I already feel sad climbing a hill by my place and even at 5K RPM I can't break 140 kph until I reach the top. I need just 20 more horse I think.