I've never really understood transmissions with overdrive, nor have I ever driven a vehicle that had overdrive. In my continual dreaming about some cool car I'm going to buy one of these days, I'm looking at one of my favorites, a Triumph TR3. I actually had one...MANY YEARS ago...and let it go because we were in no position to restore it; some time later we ran into the couple who bought it, and they had done it justice! It looked amazing. So it went to a good home. Anyway, I see that some TR3s have a manual transmission with overdrive; mine didn't have overdrive, it just had a 4-speed manual transmission. Let's say, hypothetically, that I bought a TR3 that had overdrive what, if any, learning curve would there be? FWIW, although I learned to drive on automatics, I've chosen to drive only manuals for the past ~30 years. My current Toyota RAV4 [which I will keep] has a 5-speed manual transmission. Would it be weird switching back and forth from one to the other?