what is good transmission oil?

Bster

If you're talking about the manual transmission, I've used Prodrive transmission oil on my Mini Cooper S and loved it. However, it was quite costly so I switched to other brands like Torco and Liquid Moly just to try (cause if you don't try, you'd never know for yourself), but I still prefer Prodrive.

I'm not going to tell you how buttery smooth it was or yaddah yaddah. You'd just have to try it, to believe it! =)

Your mileage may vary.

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