Trojan Boat Forum

Mobile One 15-50 Synth. Change it before haul out.

http://www.mobiloil.com/USA-English/Mot ... 5W-50.aspx

Works great. Use it in the genny too. V-Drives will be changed in the spring, they say straight 50 in the manual. So i will do that i suppose, would like to have the same in everything, any thoughts on 15-50 in the Vdrives? Should be a little better for oil pressure at start with the better viscosity being cold.

I would talk to the gear maker and see what the say . 15w-50 oil ? I would think 15w40 would do better .

prowlersfish wrote:

Allen Sr wrote:If you have high hours on the engines I personally would stay away from synthetic oil. I have seen synthetic oil wash out carbon build ups that would end up in a loss of oil pressure.

39 years working on engines for a living and that is a new one on me . I am not a big fan of synthetic oils and would only use them if the OEM calls for it But I can tell you that would never happen , there was/is a fear the changing to a synthetic with high miles/hours could cause seal leaks but that maybe a thing of the past . I have seen many switch no issues but have not seen any gains also .

The most important thing is to change it as recomended by the Engine maker .

My experience with the wash outs was back in the 80's when synthetic was just coming out on the market. Company my wife worked for did it and in a matter of 3mo's they lost 2mack engines and 5 3406B cat's. The people that did the rebuilds said the synthetic washed out all the carbon build ups and sludge. But back then you couldn't switch over on used engines like you can now. When I had my trucks I kept the rears and tranny in synthetic but not the engine. But to each their own I guess.

I don't know of any" carbon build ups" in the crank case . but you used to get a lot more sluge in the older engines . todays oils keep the engines much cleaner so that maybe part of it .

Delo 400. 1995 Crusaders 454XL with 460hrs. Changed every year, and never have to add inbetween oil changes.

Heck , I have Mamma save up all the old frying grease and now my engine smells like chicken and fries!

foofer b wrote:Heck , I have Mamma save up all the old frying grease and now my engine smells like chicken and fries!

lol.... you are one crazy dude swiming with sharks and talking about chicken and fries Gotta love it!!

Ron

I have been using Kendall GT-1 straight grade for years. Used to use SAE30 but as I started to burn a bit (30+ year old engines with almost 1700 hours) I switched to SAE40.

Straight 30W in my Mercruiser. Castrol or Valvoline. Change it at the end of every season. NAPA Gold (WIX) filter.

Diesels: Rotella-T Triple Protection 15W40
http://www.shell.com/home/Framework?sit ... etail.html

MerCruiser 454: MerCruiser Quicksilver 4-Stroke 25W40 NMMA FC‑W rated oil.

Corvette & Tiger: Valvoline 20W50

jon_e_quest wrote: Change it at the end of every season.

Whats the theory behind changing it at the end of the season? Wouldn't it be better to change it at the beginning of the season? Just let the old oil sit and protect during the cold months, and put new oil in right before you fire her up? Then the new old won't have fogging oil, moisture, etc. it in from the winter.

???

Every engine no matter how good a shape it's in has a little bit of blow by past the rings. That being said, carbon deposits contaminate your oil and create a level of acidity that can etch your engines vital internal components when stored for a long period of time. Changing the oil prior to storage prevents this.

Since I rarely "Store" my boat, I change oil 3 times a year : April-July-December. I usualy use what the manu suggests, but I think you guys got me interested in 15-40

In my little section of the universe : Piece of mind ==== "Priceless"

Ron

Paul wrote:Every engine no matter how good a shape it's in has a little bit of blow by past the rings. That being said, carbon deposits contaminate your oil and create a level of acidity that can etch your engines vital internal components when stored for a long period of time. Changing the oil prior to storage prevents this.

Exactly!

carbon deposits in oil whatever The reason for changing oil at the end of the season is because of acids and other contaminates in the oil . one school of thought is end of season and a another is start of season pros and cons to both. Now I have seen many manuals that say to change oil for storage (end of season) and in the same manual they will tell you to change the oil at the start of the season , so by the book do both


Or do what I do change it every 100 hours ( cummins recc 250 hours)
do not go over factory hours . now the end of season what do I do ? I don't know I will let you know if it ever ends