5w 30 Car Oil?!

[maczilla23]

Hello. I just bought a new boat on friday with a 190HP 4.3L. Took it to the lake today and checked the oil before running. It was a quart low so I dropped a quart of 5w30 car oil in it thinking nothing of it since it is a chevy motor.

After thinking about it I thought maybe that was a bad idea. Im going to be running the boat tomorrow and dont want to mess it up. Is it ok with a quart of 5W30 car oil in it or should I completely change the oil and start over. Id hate to ruin the engine right off the bat! Help would be appreciated!

Corrie

[paulswagelock]

Originally Posted by maczilla23

Hello. I just bought a new boat on friday with a 190HP 4.3L. Took it to the lake today and checked the oil before running. It was a quart low so I dropped a quart of 5w30 car oil in it thinking nothing of it since it is a chevy motor.

After thinking about it I thought maybe that was a bad idea. Im going to be running the boat tomorrow and dont want to mess it up. Is it ok with a quart of 5W30 car oil in it or should I completely change the oil and start over. Id hate to ruin the engine right off the bat! Help would be appreciated!

Corrie

The 5w30 oil will be ok, but not optimal. What year boat? What viscosity does your manual call for?
You can safely run the engine but you should change the oil when convenient to the recommended viscosity.

[mmwjr]

In my opinion thereal issue is mixing oil weights. was the oil in the engine 5w30? I would recommend changing it to ensure it's all the same.

BTY I alo recommend a marine oil which has extra additives for the marine enviroment (higher constant RPMs, ...)

[biggerseagar]

One quart won't hurt anything but.....read your manual what weight does it say ? Then use it. Mercury oil is not that more than what you put in your car cost wise. Walmart even sells it now....

What did the previous owner use? You should know the answer to that question. You just made an huge investment take care of it wisely and by all means have fun!

Roger

[maczilla23]

Thanks guys! I had fun on it today. Great fun! Its a 05 Maxum 1800 SR3. I didnt know walmart had mercury oil there? Ill have to pick some up from there! Thanks again.

Corrie

[biggerseagar]

They have the quicksilver brand which is just the same............

[shrew]

All Mercruiser oil is 25-40 to my knowledge. Mixing oil weghts changes the oil weight to my knowledge. Adding a single quart probably won't change it a whole lot. I'd suggest a review of the manual and specs before doing your own work on the boat.

[mmwjr]

Most engines hold 5 qts so if one is mismatched that's 1/5 or 20%, so a bigger impact than you might think. Now it is still motor oil and shouldn't cause engine failure but for the cost of an oil change to make things right is a lot cheaper than a $5K engine replacement

[shrew]

Ah yes, i didn't consider the difference in capacity changing the ratio.