I agree with Barry. Though I specifically use Mobil One Racing 4T in my RSV. It is made for motorcycles and maybe it makes no difference but I know it is formulated for wet clutches. I've been using Mobil One in everything I own for many years. I think I started using it exclusively around 1997 or 1998. I've used it in anything I've bought new and swapped to it in anything that I've bought used. Cars, motorcycles, boats, wave runners, etc. The first Venture that I bought was an '88 model with around 45,000 miles on it. Swapped it to Mobil 1 immediately after my first trip and it became harder to shift. Never had any problems after the swap and never had any leaks.
It's not cheap though. I changed the oil in my RSV this past weekend. 4 quarts of the oil and a K&N filter cost me about $65.00. The filter was too high at $16.99. Don't know if I'll use the same one next time but we'll see.