Old oil or no oil?

[Fullpass]

Would leave oil in rather than drain....old oil won't rust parts...will keep them from rusting: however, old oil will become acidic, eat away etch bearings and surfaces, people change oil every 7000 miles or 3 months, which ever is first, because of the acid formed in the oil from blow by gasoline, gone by the piston rings...extra 3 months not best practice, but would not ever leave it empty...that would be the worst thing ever to do...

[east tx skier]

No oil expert here, but I'm in the same conundrum. My boat was away having its trailer worked on and I kind of missed my winterization window other than draining the block/manifolds. After giving it some thought, I'm draining and refilling/changing the filter, and fogging. I'm sure it will be fine just this once. I know people who treat their boats much worse.

[merCrewser]

Sorry to throw a wrench into this thread.....

You can run crappy walmart oil and change it every other year and notice no difference.....

[merCrewser]

one more thing, running the boat on the trailer to change the oil is automatically contaminating the new oil with condensation because it is impossible to get crankcase temps up to operating temps with no load on the engine. Condensation will burn off in the spring during your first slalom pass

[JimN]

Originally Posted by merCrewser

Sorry to throw a wrench into this thread.....

You can run crappy walmart oil and change it every other year and notice no difference.....

I used WalMart oil for a long time in my '90 Silverado and never had a single issue. It's not as if they use 1000 different refineries and have that same number of ways to screw it up. I had also used Valvoline DuraBlend and that worked, too. Eventually, when I guessed that it was approaching 300K, I started using their high mileage oil with no problems. I sold it and still see the guy driving- no smoke or other indication of trouble. I tried WalMart synthetic in my van the last time and it actually runs quieter than Mobil1.

[thatsmrmastercraft]

This all depends upon who Walmart is contracting with to label their oil and what specifications are set. No reason that the oil Walmart is selling is junk, but no guarantee it is any good, and it might change each time you buy it.