mercury 25/40 engine oil for gas engines sterndrives

[spud123]

the container says change engine oil a mininum of every 100 hours, then in the next sentence it says or once a season? if i put on 25 engine hours this past summer what is the reasoning for the once a season?

[paulswagelock]

Combustion byproducts make their way into the oil and make it acidic.
The change at the end of the season is to prevent that acidic oil from scarring your internals.

[biggerseagar]

Figure this .........how much did you pay for your boat and how much would it cost you to buy a new engine........then figure how little it is to buy 5 qts and and filter to change in the fall before your boat away........Alittle preventative goes along way. You don't what the acidic oil sitting in the bottom of your oil pan and inside your engine because it will shortin the life of all those parts.

I only put 11 hours on my boat this year.......still both engines got fresh oil and filters and are ready to go for the next season........It is worth it!

Roger

[spud123]

thank you for your wisdom, i had full intentions on replacing the oil, i just found it sort of confusion and contradictory the labeling on the mercury jug?

[shrew]

No different than a car manufacurer advising; "3,000 miles or 3 months". Whichever comes first, NOT whichever comes last.

[biggerseagar]

Spud ....Just trying to help..........I have a friend who bought a brand new Chapperal about 8 years ago and he does it diferently...........he doesn't change his engine oil and doesn't change the drive oil in the fall, instead he waits for the oil 50 hours and whenever that happen then he changes...........his choice......would not be mine but again his choice.

I'm no mechanical engineer but I would guess in the next 5 or 6 years we will see if this good process.

Roger