I found a 93 cabriolet at the salvage yard today. It appears to have a 5 speed trans. I have a "GP" coded 4 speed in my 81 rabbit diesel. I reviewed the gear ratio charts on vortex and it appears that my 4 speed has the best gearing for mileage...even considering the 5 speeds. I was hoping to put a 5 speed in with a lower ratio so the engine wouldn't be screaming when I'm doing 70 mph. Is my interpretation of the data correct? Thanks.