What is the seat height of the 1500 goldwing verses the 1800 goldwing?

If you are comparing a post-95 model GL1500 to the newer GL1800's, there is no seat height difference (29.1"). There is a slight difference in the narrowness of the newer bike allowing for shorter legs a more direct route to the ground.

As for pre-95 models, the seat is about one inch higher and the body panels are a bit wider.