I bought my '91 Honda Civic DX Hatchback brand new in October 1990. I still own it and have no plans to replace it. There's absolutely no reason to replace it. The engine and transmission are the originals with over 369,000 miles on them. My car runs as well as it did the first time that I drove it off of the lot. The keys to its longevity are: (1) engineering design, (2) respect for my car, (3) luck, and (4) oil and oil filter changes every 2,000 miles. I get compliments for it all the time.
I Have had a 91 civic dx (with a d16z6 engine) and It drove well. They are nice little eco cars but they get stolen alot because of it. mine was a canadian model and stolen twice before 2000 when it came to the US and then it was stolen another three times. But I also have had a 91 CRX hf and they both ran well and lasted 300k+ miles. The worst part about this car this whole car is... No cup holders, but other than that and being stolen alot it was a great cheap car that got 30-40 mpg (hb) and 40-50 mpg (CRX)