So here is the background info:
2007 28 foot cruiser, single 350 MAG engine by Mercruiser.
Used 5 months per year, averaging 50 hours per season. 145 hours total on engine. Temperatures are 65-90 degrees F during the season.
I have used the Mercruiser 25w40 since new to avoid warranty arguements. Now that the warranty has expired, I am condering a different oil.
I have poured through this site for a few months now - thanks to all that posted. There is an amazing amount of information.
My thoughts on the oil is to choose an HDEO for the boat, based on the info I have gathered here. But I have a few questions. Shell Rotella seems to be a popular choice, and there are some good UOAs posted from it. So, would the Rotella T 15W40 or their T6 5W40 be the better choice? The dino seems to have more Z and P, closer to the Mercruiser spec, so I was leaning that way. But, as a process control engineer, I have seen raw crude at the refineries I have worked at, and the more processing to remove the waxes and impurities the better. I believe the T6 is a group 3 synthetic, so severely hydrotreated. I am ok with that as I am worried Esters in a PAO based oil would not hold up as well to contaminants and dilution (personal theory). The T6 does have a lower Vis at 100deg, lower than the Mercruiser by more than 10%. Both have a TBN much higher than the OEM, which I feel beeter about with all the sitting the boat does, low operating temps, etc.
I am posting the VOAs for the three oils so you do not need to go look them up to offere your opinions. Sorry for the long post, but the posts always say the more info provided, the better.
Mercruiser VOA
Moly Mag 1063
Calcium 422
Phos 1362
Zinc 1546
Titanium Silver Copper Lead Tin Aluminum Nickel Iron 2
Chrom Sodium Boron 196
Silicon 7
SAE/ISO Grade 2540
TBN 6.50
VIS @ 100C Cst 15.14
Rotella T 15W40
Iron 1ppm
Chromium 0ppm
Lead 0ppm
Copper 0ppm
Tin 0ppm
Aluminum 0ppm
Nickle 0ppm
Silver 0ppm
Silicon 2ppm
Boron 0ppm
Sodium 0ppm
Magnenesium 20ppm
Calcium 3322 ppm
Barium 0ppm
Phosphorous 1326ppm
Zinc 1499ppm
Molybdenum 0ppm
Titanium 0ppm
Vanadium 0ppm
Potassium 0ppm
VIS@100C 15.12cSt
Tbn 10.36
T6 5W40
Iron 2ppm
Chromium 0ppm
Lead 6ppm
Copper 0ppm
Tin 3ppm
Aluminum 1ppm
Nickle 0ppm
Silver 1ppm
Silicon 3ppm
Boron 65ppm
Sodium 4ppm
Magnenesium 1197ppm
Calcium 751 ppm
Barium 0ppm
Phosphorous 1078ppm
Zinc 1268ppm
Molybdenum 63ppm
Titanium 0ppm
Vanadium 0ppm
Potassium 0ppm
VIS@100C 13.62cSt
Tbn 11.2
2007 28 foot cruiser, single 350 MAG engine by Mercruiser.
Used 5 months per year, averaging 50 hours per season. 145 hours total on engine. Temperatures are 65-90 degrees F during the season.
I have used the Mercruiser 25w40 since new to avoid warranty arguements. Now that the warranty has expired, I am condering a different oil.
I have poured through this site for a few months now - thanks to all that posted. There is an amazing amount of information.
My thoughts on the oil is to choose an HDEO for the boat, based on the info I have gathered here. But I have a few questions. Shell Rotella seems to be a popular choice, and there are some good UOAs posted from it. So, would the Rotella T 15W40 or their T6 5W40 be the better choice? The dino seems to have more Z and P, closer to the Mercruiser spec, so I was leaning that way. But, as a process control engineer, I have seen raw crude at the refineries I have worked at, and the more processing to remove the waxes and impurities the better. I believe the T6 is a group 3 synthetic, so severely hydrotreated. I am ok with that as I am worried Esters in a PAO based oil would not hold up as well to contaminants and dilution (personal theory). The T6 does have a lower Vis at 100deg, lower than the Mercruiser by more than 10%. Both have a TBN much higher than the OEM, which I feel beeter about with all the sitting the boat does, low operating temps, etc.
I am posting the VOAs for the three oils so you do not need to go look them up to offere your opinions. Sorry for the long post, but the posts always say the more info provided, the better.
Mercruiser VOA
Moly Mag 1063
Calcium 422
Phos 1362
Zinc 1546
Titanium Silver Copper Lead Tin Aluminum Nickel Iron 2
Chrom Sodium Boron 196
Silicon 7
SAE/ISO Grade 2540
TBN 6.50
VIS @ 100C Cst 15.14
Rotella T 15W40
Iron 1ppm
Chromium 0ppm
Lead 0ppm
Copper 0ppm
Tin 0ppm
Aluminum 0ppm
Nickle 0ppm
Silver 0ppm
Silicon 2ppm
Boron 0ppm
Sodium 0ppm
Magnenesium 20ppm
Calcium 3322 ppm
Barium 0ppm
Phosphorous 1326ppm
Zinc 1499ppm
Molybdenum 0ppm
Titanium 0ppm
Vanadium 0ppm
Potassium 0ppm
VIS@100C 15.12cSt
Tbn 10.36
T6 5W40
Iron 2ppm
Chromium 0ppm
Lead 6ppm
Copper 0ppm
Tin 3ppm
Aluminum 1ppm
Nickle 0ppm
Silver 1ppm
Silicon 3ppm
Boron 65ppm
Sodium 4ppm
Magnenesium 1197ppm
Calcium 751 ppm
Barium 0ppm
Phosphorous 1078ppm
Zinc 1268ppm
Molybdenum 63ppm
Titanium 0ppm
Vanadium 0ppm
Potassium 0ppm
VIS@100C 13.62cSt
Tbn 11.2