I know this has been driven pretty hard, but I got some conflicting information from my Honda dealer today. I went in, and asked to buy some Manual Transmission Fluid. The guy (a Honda certified service technician) looked at me funny, and said "It's just motor oil." When I asked to buy it, he told me "No, it's just motor oil. Use motor oil." I asked if 5w-30 is alright, and he said "Or 10W-40, or 15W-30, it doesn't matter." Now. Knowing what I've read, the Honda MTF has some friction modifiers in it that help prolong the life of the transmission. But why should I use it if the dealer told me not to? My car is siting at 210,000 km right now, and I will probably hit 250k by the end of the year. Should I use 10W-30 and put a friction modifier in it? I can buy the MTF online, but it seems kinda dumb to ship MTF. What should I do? This weekend I'm going to change fluids for the winter, swap out the summer tires for winter tires, do an alignment, check valves clearances, etc.