What oil & viscosity do you use?

So this morning I was on my friends 1996 sport Nautique and we were talking about regular maintenance. I asked him what oil he used and to my surprise he uses Valvoline 5W-20. Now I don't have anything against Valvoline but doesn't that seem like a pretty thin oil for a boat in Arizona?
I have an 04 VLX with the 340 monsoon and use Pennzoil 20W-50.

So out of curiosity. . . What do you guys out there use?

Boat-
Engine-
Location-
Winter/Summer-
Oil-

'00 Mastercraft 230 VRS
5.7L Indmar LTR
Louisiana
Year round
15w40

40w fleet oil
Lewisville Tx
Year round

isnt that a gear oil?

15w40

2002 SANTE 210
Dallas, TX
year round
Valvoline 10w40 synthetic

Marine oil or standard?

I use filtered bacon grease. Cheaper and has added benefits. Yummy:-)

Anybody ever port/polish their intake and exhaust with silica sand?

2005 Malibu VLX
Murrieta, ca (so-cal)
Year round
Delo high performance motor oil
15w40

Mercruiser 15/40

The 351 Ford's are flat tappet motors and the need to have some ZDDP to lube the cam. Valvoline VR1 or Mobile 1 both in 20w50 seem to be the easiest to find. I use the Mobile 1 in my Nautique, it's less than $30 a jug at Wallyworld.

Interesting you should say that, I had this question recently and was assured by a local marine shop 10w40 syn was sufficient. After a quick search over at PN on flat tappet motors, I'm now headed to walmart.
Thank you and thanks DC for the thread!

Originally Posted by tx_foilhead

The 351 Ford's are flat tappet motors and the need to have some ZDDP to lube the cam. Valvoline VR1 or Mobile 1 both in 20w50 seem to be the easiest to find. I use the Mobile 1 in my Nautique, it's less than $30 a jug at Wallyworld.

What's ZDDP?

Zinc dialkyldithiophosphates (often referred to as ZDDP) are a family of coordination compounds invented by Castrol that feature zinc bound to the anion of dithiophosphoric acid.

Crankcase oils with reduced ZDDP have been cited as causing damage to, or failure of, classic/collector car flat tappet camshafts and lifters which undergo very high boundary layer pressures and/or shear forces at their contact faces, and in other regions such as big-end/main bearings, and piston rings and pins. Roller camshafts are more commonly used to reduce camshaft lobe friction in modern engines. There are additives, such as STP(R) Oil Treatment, and some racing oils such as Valvoline VR-1[4], are available in the retail market with the necessary amount of ZDDP for engines using increased valve spring pressures.

Nice, straight out of some dictionary! Lol

It used to be in most oils, as the motors have gone to roller cams there isn't as much need for it in newer motors. To extend the life of the cats they have removed it from oil which is the problem. This now includes the diesel oils. What oils have it still has been a moving target the last few years as it has been removed. The VR1 and Mobile1 are listed as racing oil because of the additive package which has the ZDDP as well as there other additives and are designed to be changed at normal intervals unlike other racing oils which may need changing after a few uses.

08 Moomba Mobius LSV
325 Indmar
Houston, TX
Year Round
Amz Oil Full Syn 15W-40

Nautique

GT 40..........Straight 40w

Excaliber 330hp........15w-40w

Boat- Sanger D215
Engine- Mercruiser Scorpeion 330
Location- Canada
Winter/Summer- LOL
Oil- Castrol or Mobil1 5w-40

Tuneman, I tried using the filtered bacon grease but found that not having it available for my breakfast consumption stopped the hardening I was getting in my arteries. This in turn made it much more difficult to stay standing up when I got tired. I had to go back to regular products for the boat to keep me functioning. (The Merc doesn't mind running on that packaged stuff.)

15w40 98 Malibu vlx