Carver Owners Forum

Personally I would check the owners manual for their recommendation. Like others I use Rotella 15W40 on my Crusader 6.0's.
The manual stated NO SYNTHETIC oil... for whatever reason.
Probably Viper can tell us why they would require that recommendation.

Again, I'm pretty sure it was a matter of opinion back then. There were obvious reasons for not using synth during new engine break-in periods but I don't know of any reason for not using it afterwards. As I mentioned, I suspect OEMs today have no problem with using synthetics in any model year. Merc actually recommends it as their first choice now no matter the year. This was a departure some years ago from their initial recommendation to stay away from synthetic blends, but formulations and ways of thinking based on field experience and R&D change over time.

Come on Viper, tell us the whole story. Mercruiser simply did not sell synthetic oil at the time so they did not recommend i, then like magic when they bottled their own it was almost a must use.

That's entirely possible, who knows. After synthetics came out, its use in their older engines was a common question brought up at every training session I attended. The answer from all the trainers was they weren't prepared to take that leap for older models until research indicated no ill effects from using synth blends on older builds engineered with dino oils in mind. Don't forget too, before they came out with their own synthetic formulation, they were already producing engines that required synthetic oil which they knew consumers would have to buy from a third party until they formulated their own blend.

Ya I think those of us that are old enough to remember what was happening to older engines using first generation synthetics can all relate to the issues buddy mentioned in the video re leaks, etc. Like I said, formulations change and so do minds based on those changes. When synthetics first came out, I remember the talk being that they should not be used in marine engines as they didn't have the desired properties needed for the way our engines are run and the conditions therein. Of course that is not the case now.

I fried two turbos on my 210 Hinos bringing my Bayliner home from Lake Erie. It was pure ignorance on my part, no warm up or cool down. I consulted an Engineer who worked in research for a large oil company about using synthetic oil in a then 24 year old motor. The researchers had no reservations about making the switch. I owned the boat for seven years and the Hinos ran awesome. I now have Cummins 450’s in my Carver and changed the oil in the fall and stared using Rotella T6 synthetic. I’m a fan of Mobil1 but I couldn’t find the grade recommended. I know I might be spending more than I need to, but figure since I’m changing the oil myself I’m saving money. On another note I now work at a major oil companies research center where they test motor oils and other lubes.
Pete

Love the Hinos. Wasn't crazy about their oil filter assemblies though but it was easy enough to upgrade. Great engines IMO, bullet proof, easy to work on, simple operation, and lots of power for their size. There were a couple of things to be aware of but what engines don't have that. I always liked the layout of that model Bayliner and the lines were sporty. The access to the engine compartment through a door from the cockpit was a handy touch and made it really easy to access the engines.