Jon, I think my 216 is in the same boat as your Corolla, as far as economy goes. I can see the difference on the vac gauge at, say, 50mph in 4th vs 5th.
I'm running the T-5 for the increased top speed first and foremost, and the synchros second (think lots of lights, stop signs, and stop & go traffic). Any potential fuel economy from the overdrive was wishful thinking, though the numbers the 235 guys are showing here aren't bad, and I look forward to seeing how my 57 235 does whenever it's finally swapped into my '50.
