Here are the major differences (I'm assuming we are talking about an SI):
1984 - CRX was introduced, I don't know much about this year (mainly because there was no SI) I know it had a 1.5
1985 - CRX Si introduced, If I am not mistaken it was the first fuel injected car Honda offered here (Prelude was 1986) This CRX Si still retained the in-set headlights and 2 tone paint. It was the start of the CRX Si's trade mark up-and-out sunroof. It had wheels that were unique only to 1985 CRXsi. This year Si was said to be the quickest because of it's lightweight (no ground effects) I raced one with my stock 1990 Si and did get very slightly out run.
1986 - Si got cool ground effects that were body colored, as well as flush mounted headlights (all CRXs) a cool foam spoiler, and new wheels.
1987 - I believe was unchanged
1988 - CRX redesign, Si got new 1.6 16valve SOHC 105HP engine base engine was the engine from the previous years Si. Entire car was new. Amongst other things, now the car had 4 wheel independent suspension.
1989 - Si got a tiny bit heavier due to the stronger doors which had to incorporate the new passive seat belts. The engine was slightly bumped to 108HP
1990 - Si received 4 wheel disc brakes, new rounded instrument cluster, revised front and rear lights, revised front and rear bumpers. The seats were the same style, but had red stripes instead of grey. And the wheels were a new turbine style (same size).
1991 - Last year
I'm pretty sure was the same except for the bluish-green color was added to the Si lineup.
I'm sure I missed a few minor things and someone will chime in, but I think this is pretty complete. Now the overseas markets, forget it!! They got all the cool stuff. A matter of fact our 1.8 top-of-the-line SI engine was there base engine!! If I remember correct in Japan the base had 1.6 108HP engine, the SI had the 1.8 integra type engine with 135HP and the SI-R had the 160HP 1.6 VTEC. That VTEC engine came out in 1988 in Japan (CRX had VTEC even before NSX) and was the same as the Del-Sol 1.6 VTEC that came out here in 1994 (i think it was 94) That engine was already roughly 6 years old by the time us poor Americans got it!! As for the rest of the car!!! I was pissed off, we got roll-up windows and no back seat (bad for insurance) in Japan!! they got a back seat, power windows and locks, power steering, leather seats, cruise control nicer wheels and a cool spoiler (and I'm sure some more goodies) There was even a glass roof model, kinda like the newer Porsche 993 and 996 targa (but not retractable).
Anyway enough about CRXs....I'm only 29 and I have own 30 cars in my life but none have compared to the fun I have had in my 4 CRXs......except the NSX.
Regards,
John