Oil Viscosity

[62cruiserinc]

I have a 1981 Sea Ray SR260 Sundancer with the 5.7L engine. I bought the boat last year and the previous owner said he replaced the engine with a crate motor about 8yrs ago (There is a Jasper Engines label on the motor).

I have looked through old posts on engine oil viscosity and they said to stay with the SAE 30 originally recommended by Mercury in 1981. Does this recommendation hold even with a newer engine installed?

I use synthetics in my cars. What is a good oil to use for marine applications? (This is my first boat).

Steve

 

[Bt Doctur]

Rotella 15 w- 40
merc 25w-40
any GOOD quality 20 w-50
1st boat, then you need a owners manual, operators manual and a service manual

 

[62cruiserinc]

Thanks for the recommendations.

The first thing I made sure I had was the owners ,manual and service manuals because I do all my own work. Last year I did replace the impeller and gear oil.

Steve

 

[Bondo]

Ayuh,.... Rotella T, 15W-40 is the only oil I use in boat motors,.....
'n truck motors,....
'n dozer motors,.....
'n every other motor in our fleet,.....

 

[62cruiserinc]

I bought the Rotella T4 15W-40. It says that it's formulated for diesel engines. This is still OK for my gas engine?

Steve

 

[stonyloam]

Sure is, I, like bondo use it in everything, tractors, combine and boat.

 

[Scott Danforth]

I bought the Rotella T4 15W-40. It says that it's formulated for diesel engines. This is still OK for my gas engine?

Steve

yes

you can even splurge and get the T5 blend or T6 synthetic. however at $11 a gallon for the T4, you cant go wrong. its fantastic in boats

I run it in my boats, lawn equipment, step-sons car. used to run it in old truck and old car.... till I sold them. however now I run Rotella 5W20 synthetic in the new truck, new car and wife's car.

 

[62cruiserinc]

Thanks, guys.

I'll use the T4 that I bought and maybe get T5 or T6 next time.

Steve

 

[achris]

Many years ago I was looking for an oil to run in a 'mixed' fleet (petrol engine boats and diesel engine cars), and the research lead me to a few conclusions. The internal pressures and shear forces on oils in diesel engines is far higher than in petrol engines. Diesel engines usually require higher detergent levels, and lower sulphur levels... Basically, diesel engine oil had to be 'better' than oil required in petrol engines, so I opted for running diesel engine oil in everything... Not had a problem because of it. And Rotella 15W-40 is about the cheapest oil on the market. Wins all round.

Chris.......