Oil weight and Grade
09-07-2010, 04:07 PM
#1
Registered
Thread Starter
Join Date: Jul 2008
Location: Kent Island, Md
Posts: 32
Likes: 0
Received 0 Likes
on
0 Posts
Oil weight and Grade
So, for all you motor heads, me included what types of oil do you use on your big blocks. I have a set of 496's and have read 3 different things from Mercruiser. 20w40. or 25w40. First they said full Synthetic and then blended. I have always used Royal Purple 15w40 but would like some other choices. Still change every 50 hours. In the generator straight 30W Synthetic.
09-07-2010, 08:49 PM
#3
Registered
Can't go wrong with a good quality 20W-50 form Kendall, Castrol, Valvoline or Pennzoil. If you want to spend more money look to synthetics. There is a good thread called "marine lubrication" that has a lot of good information.
Last edited by kjm5125; 09-07-2010 at 09:01 PM.
09-08-2010, 05:38 AM
#4
Registered
Thread Starter
Join Date: Jul 2008
Location: Kent Island, Md
Posts: 32
Likes: 0
Received 0 Likes
on
0 Posts
I was looking into the Royal Purple full Synthetic 15-40. This is close to the 25-40 Merc recommends. I run my boat 90% at 3000 RPMs so a very heavy weight oil won't be needed. I looks like Sierra is the same as Mercruiser oil but different label?
09-08-2010, 06:35 AM
#5
Registered
We've always used M1 15w50. Good oil at a good price. Just bought six 5 qt jugs on sale at Walmart for $21 a jug.
09-08-2010, 06:59 AM
#6
Registered
Thread Starter
Join Date: Jul 2008
Location: Kent Island, Md
Posts: 32
Likes: 0
Received 0 Likes
on
0 Posts
I was looking into the Royal Purple full Synthetic 15-40. This is close to the 25-40 Merc recommends. I run my boat 90% at 3000 RPMs so a very heavy weight oil won't be needed. I looks like Sierra is the same as Mercruiser oil but different label?
