anybody using synthetic oil

[Jim Hardesty]

While I was picking up my Rotella T for my end of season oil change noticed Shell also had synthetic blend and synthetic oil.  Both claimed to be compatible with regular oil.  I've always used Rotella 15w-40 with Lucas additive.  My reasoning for using the additive is the engine sitting days/weeks/months without running. 
Question to people that know more about modern oil is.  Should I switch to synthetic synthetic/blend?  What would be the advantage or disadvantage?  Is Rotella best synthetic?
Jim

[Paulus]

Jim, My understanding is that if you used regular oil in your engine, you can not switch to a synthetic.  I have asked at Torresen and also where I have my truck serviced.  I am not an expert.  Will be interested in what the experts have to say.
Paul

[KWKloeber]

Jim

Same old story that's been told on here before and can be found in the searches.

YBYC, but I use DINO, no Dino blends are touching this engine block, no additives, CF rated only. Rosella T-1 meets the specifications for our engines. Not only are synthetics a WASTE of boat bucks, Synthetics are NOT recommended for OUR marine engines.  OTR heavy diesel trucks are a completely different animal.  I previously posted the industry findings (or a link to it can't recall which offhand.)

Ken

[KWKloeber]

Some info.
http://docs.wixstatic.com/ugd/3bd504_eec473b8b1144dccb338ca2cd51b9dbc.pdf

Rotella T-1 SAE 30W is pure Dino.  Or of you need a multi viscosity (if you typically run in warm and then colder climates and need additional cold start up protection) Kubota 10W-30 and 15W-40 are pure Dino and basically the same price as Rotella T-1 that I just bought on sale at AutoZone.  Personally I'll probably switch the Kubota multi just because....  Messicks (major right coast Kubota equipment dealer) recommends 15W-40 for our engines.  That makes sense as it's also better for the HOT climates.  (No. I'm not a Kubota dealer or sell Kubota oil, or have stock in Messicks!)

Just don't mess with synthetics -- the bearing journal you save might be your own.  YBYC

Cheers
kk