Boat motor oil what happens if you use conventional instead of 4 stroke?

Question

curious as to what can happen to an outboard motor if you run 10w-30 that would go in a car instead of 4-stroke motor oil.

Answer 1

Most likely nothing will happen. The only problem that I could think of is if you used an oil that had an older rating such as an API SD instead of a newer API SL rating. Newer ratings still meet the older rating needs but the old ones do not meet the newer needs. You can use an SL rated oil in an engine that needs SF rated oils but you should not use SF rated oil in an engine that needs SL rated oil. What could happen? It may not meet the viscosity levels or heat levels required, or it may not have the same level of detergent added. This applies to any 4 stroke, marine or automotive. Diesel engines require oil with a C rating and should not get S rated oils.

Answer 2

Car motor oil should work fine in a 4 stroke boat motor. The problem  come with using 4 stroke oil in a 2 stroke motor.  2 stroke boat motors mix the oil with the fuel for lubrication , so this type of oil is formulated to burn without fouling the plugs.  If your boat motor is a 4 stroke then car oil is ok, because does'nt get burnt with fuel.

Answer 3

Nothing...same stuff.

Answer 4

nothing.

Answer 5

Oil reduces friction. Boat motors run at a higher rpm and develop more friction. All oils are manufactured for operating under a given condition. Higher friction will create overheating and consequently break down of the metal parts.

Answer 6

10W30 is 4-stroke oil. (That is, cars use 4-stroke engines.) Do you mean 2-stroke oil? I wouldn't recommend substituting one for the other; 2-stroke oil is designed to be mixed with the gasoline in a 2-stroke engine.

The way a 2-stroke engine works (pressurized crankcase etc), the fuel/oil mix provides both lubrication and fuel. (That's why they smoke if you use too much oil in the mix.)

4-stroke engines, like in a car, keep the oil and fuel separate (well, that's the theory, anyway.)

I would say that:

* If you use 2-stroke oil in a 4-stroke engine, you might either clog the oil delivery system or not provide enough lubrication -- and ruin the engine.

* If you use 4-stroke oil in a 2-stroke engine, it might not run at all (might not be able to burn the stuff), or you could run into the same problems above.

They're designed for a specific purpose for a reason -- I wouldn't try substituting them unless you didn't have any other choice and needed the engine to work badly enough to risk ruining it.