how many run synthetic oil in there 525's ?
#13
Gold Member
Gold Member
Join Date: Jan 2004
Location: Houston, Texas
Posts: 491
Likes: 0
Received 0 Likes
on
0 Posts
I've researched this. Merc's website states to use their oil. Then is says, if none available, then using a good grade oil is ok. However, I've heard that marine oil has additives that deter water ingestion.
#14
Registered
#15
Registered
Join Date: Feb 2007
Location: Battlefield, MO
Posts: 268
Likes: 0
Received 0 Likes
on
0 Posts
Correct me if I am wrong here guys..and I am sure someone will!lol....but I believe the only reason you would not want to run synthetic is either...you just built an engine and you are better off on break-in with a mineral based oil.....or.. with synthetic oils sometimes the roller lifters tend to skid rather then roll because of the lubricity (too slick) of the synthetic oil..but Mobile 1 has been said to not have this problem. I run Mobile 1 20/50 in my HP500 and I can see better oil pressure with it over the syntec blend 20/50
#16
Registered
Ken
#17
Registered
Join Date: Feb 2007
Location: Battlefield, MO
Posts: 268
Likes: 0
Received 0 Likes
on
0 Posts
Well, I see where you are going with that..but in fact what happens is the roller will get a flat spot if it is skiding more than rolling and eventually end up wearing down a cam lobe.
#18
Gold Member
Gold Member
Join Date: Jan 2004
Location: Houston, Texas
Posts: 491
Likes: 0
Received 0 Likes
on
0 Posts
The other reason to not use synthetic oil in a Merc 525efi is if it's still under Merc's warranty! They say no, no, no to synthetic. I got this info from the brass.
#19
Registered
If you are worried about warranty, use a certified oil based on merc's specs. That is currently NMMA FC-W.
I'd probably go with Amsoil Marine Synthetic.
http://www.nmma.org/certification/pr...asp?y=FC-W2007
Out of warranty, Mobil 1 15-50.
I'd probably go with Amsoil Marine Synthetic.
http://www.nmma.org/certification/pr...asp?y=FC-W2007
Out of warranty, Mobil 1 15-50.
#20
Gold Member
Gold Member
Join Date: Jan 2004
Location: Houston, Texas
Posts: 491
Likes: 0
Received 0 Likes
on
0 Posts
Let me clear up my comments: I am refereing to Mercury Racing, not Mercruiser or Mercury Outboards. I was informed by Mercury Racing brass, that they do not authorize synthetic (Amsoil, Mobil 1, etc.) to be used in the "blue" motors while under warranty. I disagree with their stance. I have heard more than my share of arguments for mineral oil and for synthetic oil. I'll leave it at that.