V-Drive, Transmission and Engine Oil for 2001 SAN with GT40

[SAN4Fun]

Due to some changes in recommendations from Nautique over the last few years, I would like to verify which fluids to use.

For engine oil,. I have been using Rotella T4 15w-40. I don't run the boat in cool weather. The manual recommends 40w40 for temps above 50 degrees, but I know this recommendation was changed several years ago.

For v-drive oil, the manual says SAE #30 weight. Is this still the case? I know PCM makes a v-drive fluid. Should I use that or just any #30 weight? I have a Walters v-drive.

For transmission, the manual recommends Dexron. Is there a specific brand that anyone can recommend?

Also, should I change to fully or partially synthetic fluids or stick with conventional?

Thanks!

[Jonny Quest]

Ask this question to 10 different people and you will get over 25 opinions back. OIL THREAD !!

What I did in my 351W small-block Ford engines: Full synthetic oil. High zinc or ZDDP. My preferences are: Valvoline VR-1 Racing 20W-50. Shell Rotella T6 has 1,200 PPM of ZDDP, so that is also a very good option. Royal Purple HPS 20W-50 also very good. For ATF in the PCM transmission, I like the Valvoline full synthetic Multi-Vehicle Max Life. I've heard some say that full synthetic ATF is "too slick". I call BS on that. I ran full synthetic ATF for many years in my PCM 40A trannys. For V-Drive, SAE 30 non-detergent. Valvoline has a good optioin.