You Cummins diesel guys.. Which engine oil?

[IRGuy]

I am about to change my Cummins 6B engine oil for the first time, prior to my 180 mile delivery trip to my home. Engines are 1996 models.. 315 HP, 500 hours.. bought the boat this past Feb. The previous owner didn't use the boat in the past two years very much if at all.. and I can verify the last oil change was two years and about 50 engine hours ago. The previous owner did not keep any kind of logs, so I have zero info on his change frequency, what was used, oil consumption, etc. Since buying the boat I have run her about 40-45 hours, burning up the old fuel and doing sea trials and a run to and from a diesel shop about 35 miles away I read all kinds of comments on using synthetic vs "dino" oils, high detergent vs whatever is not high detergent, one mfg vs another, etc, etc. One concern I have picked up is that the modern high detergent oils might over time cause seal failures in engines designed to use low detergent oils. I have searched this forum and looked at a series of posts on the Boatdiesel forum, and am as confused now as I was before, maybe even more. My position is.. engines are expensive, oil is cheap, I would use a $10 a quart oil and change it every 25 hours if I knew it would have any real benefit to my engines.. on the other hand I don't want to waste money or resources needlessly if a $3 a quart oil changed every 100 hours resulted in the same wear and tear on my engines. I sort of get the impression that any oil that meets the engine manufacturer's specs and is changed sooner rather than later is OK, but I need to have a warm comfy feeling that I am being good to my engines, which I have come to love and respect. So.. I ask the guys I trust... you! What oils are you all using? What mfgr, what viscosity range? How often do you change? Any other comments? Frank B - IRGuy@aol.com "Phoenix" 1983 FBC Wilmington, NC

[Sean B]

Frank, I beat that subject to death a couple years ago, and I ended up deciding that the Shell Rotella T 15W-40 was a fine pick. Lots and lots of guys use this oil in the diesels, both in boats and in construction equipment, and it is good. Change your oil every year or every 100 hours, whichever comes first, and you will be fine. Sean Burlingham "Island Time" 1987 Bertram 33 SF Melbourne, FL SBurlingham@cfl.rr.com [img]http://www.bertram33.com/photogallery/p ... d_Time.jpg[/img]

[Sean B]

Here is a link: http://www.rotella.com/products/rotella_t.html Sean Burlingham "Island Time" 1987 Bertram 33 SF Melbourne, FL SBurlingham@cfl.rr.com [img]http://www.bertram33.com/photogallery/p ... d_Time.jpg[/img]

[franklyprice]

Frank, Of course I have gas engines in my boat but I do have a fair amount of experience with both gas and diesel engines over the years so feel pretty confident giving my opinion about different oils. In my gas engines I run mercruiser 25w 40 which seems to be a good quality oil and when I was inside the engines a couple seasons ago after 1200 hours, they looked virtually new inside. Obviously I haven't owned the boat for many of those hours and so have no idea what kind of treatment the engines have had over the years but I can assume that they have had no more than regular maintanance with whatever oil the yard used on everything else. Point is, good qualty oil , the correct weight changed regularly is what will be the most important thing. Now you have turbocharged diesels which are tougher than a gas engine on oils and you are smart enough to know it. If it were my engines, I'd run whatever weight Cummins recommends with a good quality oil like Chevron delo 400(I think) or shell rotella. Thes are oils that have been around for a long time and proven themselves over that time to be really good diesel oils. I think that a synthetic oil is a little better but am not sure if they are worth the extra money since changing it at approx. 100 hour intervals you're not really breaking down petroleum oils at that interval. So to sum it up, if it were my engines, I'd use the weight recommended , one of the brands I mentioned and change it every 100 hours or so and I would bet that you will never see an oil related problem. Those engines should outlast you and I. I wouldn't be too concerned about seal failures from oil on engines of that vintage. That's my opinion for what it's worth.

[jav]

I'll second the deisel formulation Shell Rotella T 15w40 (non-synthetic). The Delo 400?? was also a very good choice (probably preferred by many) but they went through a reformulation a couple of years ago and the version that used to get great reviews has changed to a new name. I don't recall the details off hand... but I'm pretty sure it's no longer the 400 version even though that designation still exists. The info should be available on boatdiesel if you search on Delo.

[photo finish]

I use the Shell Rotella T 15w40 for my new Crusaders as reccomended by my installer

[photo finish]

Oh, and i buy it at Wal Mart

[IRGuy]

Thanks guys... I am off today to SC to hopefully complete all the loose ends and get "Phoenix" ready for the trip north. It has been a long summer! Frank B - IRGuy@aol.com "Phoenix" 1983 FBC Wilmington, NC

[Don33]

quote:Originally posted by franklyprice Frank, ...In my gas engines I run mercruiser 25w 40 which seems to be a good quality oil and when I was inside the engines a couple seasons ago after 1200 hours, they looked virtually new inside. Frank, I have gas as well and currently use Castrol 40W Assuron (a diesel engine oil) in my Merc 454's. On my last boat, a B28 w/350's, I used 30W Dryden Dieselall (brand name has switched to Assuron) and the engines ran like new with over 1400 hrs! The 28 had a Reverso oil change out system which made frequent oil changes a snap. I really miss not having one of those gadgets on my current boat. Don