175/70-13 vs 185/65-14 is almost exactly the same diameter. Only the 1996 had the 13", the 97 and up had 14" steelies. Bruce, what size wheels and tires do you have? Brad, what do you have? And what is your rpm at 60 mph?
Here are a couple of sources. They have some errors, and disagree with each other in some places. That's why I posted 2, but I still take the real-world results from my DX and Bruce's HX with more authority.
Reference: Transmission Specs - ClubCivic.com - Honda Civic Forum
6G Civic Trim Differences - Honda-Tech