10w 30 or 25w 40

[buckshot]

Hello, I'm getting ready to do the oil change for the first time on my Mercury 250 Pro XS V8. I've seen videos (Matt Becker fishing and John Crews) doing their oil changes and both using 25w 40 oil and both saying that is the correct oil to use for the Engine. However, I've read and it seems people are adamant that the 10w 30 is the correct oil to use. Can someone steer me in the right direction on why 10w 30 is more appropriate than the 25w 40. Are you fine using 25w 40? Thanks in advance.

[biglakespecks]

Called mercury to discuss oil pressure and oil temperature and rep said in south la with the heat might be better 25w 40. The temp that day was 99 in the shade heat index of 115 degrees. So i said should I go back and change the 10w 30 and go to 25w 40 and he said no that it should be good. Mercury 225 2b776205 pro xs four stroke.

[howieranger]

Your owners manual clearly states 10 w 30 for your motor. The 25 w 40 is for sustained high temp areas as Big stated.

[buckshot]

Ok, thanks for the information. Looks like the 10 w 30 it is.

[EuropeanAM]

Please take a moment to review the Announcements at the top of the Forum, and be sure to provide the REQUIRED info (serial number) when posting. Thanks!

10w30 Synthetic Blend is the correct choice (Mercury or Quicksilver.... 5.5 to 6 quarts to achieve correct level).

[buckshot]

So I drained the oil from the motor today and it overflowed a second gallon jug. This was the first time I've drained the oil. Is this common? Also, would it take more than the recommended 5.5 to 6 quarts to achieve the correct level seeing that so much drained out initially?

[EuropeanAM]

I have achieved the correct level with no more than 6 qts. in every V8 Fourstroke engine I've serviced (so far).