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  Topic Review (Newest First)
10-09-2013 02:35 PM
Re: Frequency of Changing Oil & Fuel Filters

This thread reminds me I need to change the oil in the boat, tractor, 2 trucks and 2 cars. I am due.

In my current 4 cars (between 23 abd 26 years old and having between 160K and 250K miles, and all daily drivers) I use only dino oil. Also use dino oil in the Yanmar boat engine (34 years old). These engines have never had an oil related problem. The engines have never been "opened" up for any internal engine repair. These engines do not drip any oil and no oil seals have ever been replaced.

I'll stay with the dino oil. I change the boat oil twice a year. and the cars between every 6 months and every year depending on miles. Here in Hawaii temperatures are stable year round. When I lived in cold climate I would change the oil every 6 months no matter what the mileage. I think you get a lot more contaminates in the oil when starting and running in cold climates.

The other thing to think about, when changing oil (especially in a boat), a good deal of oil is still left behind. That oil has contaminants in it that will contaminate your new oil. I like having frequent oil changes to get rid of these contaminants.
10-07-2013 08:07 PM
Re: Frequency of Changing Oil & Fuel Filters

Some points above are hard to follow, but its seems that some are advocating to skip the Fall oil change prior to layup. If I read that correctly, I have an observation to share. Have you pull the dip stick and seen the oil change from bright amber when new to dark and black? Pretty typical in a diesel, even more so in bigger bore diesels.

Those are contaminants that are bad for your motor. Modern oils have additives that are supposed to protect the motor for a short period of time, however, not all winter. Particularly, not after the oil is a full season old already anyway.

It's your motor, do with it as you wish.
10-07-2013 05:30 PM
Re: Frequency of Changing Oil & Fuel Filters

I have something of the opposite dilemma to the original poster. I am doing about 120 hours a year, slightly over the 100 hours recommended interval. At around 90 hours the oil is looking very nasty, and I start getting a little mist from the dipstick tube. Clearly it's going out of grade.

So do I change it every 6 months? Stick to 100 hours? Extend it to 120 and change once a year? What does everyone else do?
10-07-2013 05:05 PM
Re: Frequency of Changing Oil & Fuel Filters

Originally Posted by hellosailor View Post
But hey, if you want to spend the same amount of money using an obsolete product and consuming twice as much of your time and effort......Isn't that really the way it works out when you do it twice as often? You're not saving anything! And, you're creating twice as much waste in the recycling stream, for the filters and the oil alike.
Since I change the oil myself ONCE a year no matter what oil I may have used, I don't believe it is costing me any extra time or waste. And the old oil goes into the marina oil recycle tank that is used to heat the place anyway.

I don't know when oil became "obsolete", but based on my oil analysis it is doing a great job!

Synthetic oil has been around way longer than my engine, but just old obsolete oil is what the manufacturer says to use. But if it makes you feel good I'm all for you using it in yours.
10-07-2013 03:34 PM
Re: Frequency of Changing Oil & Fuel Filters

i change my oil every 100 hours and filters double time.
i change my oil before i sit for summer and after i travel the needed miles to get to wherever i go. sometimes i change oil underway.i changed it before runaway diesel and again just after, and again just before i sail out, and .... mine gets changed many times annually.
i usually travel no fewer than 200 miles each trip, unless bay hopping.
10-07-2013 02:50 PM
Re: Frequency of Changing Oil & Fuel Filters

"But if you want to use the synthetic and spend more money and then replace it less in order to SPEND THE SAME AMOUNT go ahead."
And who changes your oil for you, wee little elves in the middle of the night?
To me an oil change consumes at least 1/2 hour of my time, draining it out, pouring it in, cleaning up the spills, dumping the old oil someplace, buying new oil and stockpiling it or making the extra trip (add more time), so saving half the oil changes liberates at least a half hour of my time, probably closer to an hour.
And then there are also half as many spills or cleanups. If you think you are only saving ten bucks on oil, or twenty bucks on oil and a filter, you're doing the math wrong.

Then there's the engine itself. I started using Mobil1 back in the mid-0's when it was a radical new product available from no one else. That's because I saw the engine tear-down pictures of commercial fleet engines run on premium motor oil versus synthetic. Take off the valve cover, and the best motor oils you can buy still will leave it coated with tar and coke. Some of that flakes off, and now you've got an oil failure when it plugs an orifice. Same engines, same use, with full synthetic oil? There's no coke, no tar, no blockages.

You don't need a lab to see obvious differences that can literally make or break an engine. But hey, if you want to spend the same amount of money using an obsolete product and consuming twice as much of your time and effort......Isn't that really the way it works out when you do it twice as often? You're not saving anything! And, you're creating twice as much waste in the recycling stream, for the filters and the oil alike.
10-07-2013 02:43 PM
Re: Frequency of Changing Oil & Fuel Filters

This is just getting crazy. Regular oil is pretty inexpensive even the "good" stuff. But if you want to use the synthetic and spend more money and then replace it less in order to SPEND THE SAME AMOUNT go ahead. Hey its' your engine!

When it comes to oil only 2 things can go wrong for you: 1 - you didn't have any in the engine, 2 - it went bad because you are stupid cheap

I'm also in the change the oil in the spring camp. I see no reason to allow good oil to sit in the engine all winter collecting water and then use it the next season. I doubt that the oil I put in at the beginning of season went "bad" in 6 months and less than 100 hours of operation.
10-07-2013 12:50 PM
Re: Frequency of Changing Oil & Fuel Filters

I think Maine has the real issue here. How many failures are due to oil related failures? Will synthetic help a motor last longer than one that has proper 100 hour or once a year changes? I doubt it, at least not in a sailboat. In a trawler that does a few hundred hours a week yes it might, but I doubt it will in a sailboat. What is the main cause for failures in a sailboat, I think from my years of watching the forums, (as I have not yet experienced one) it seems to be overheating and head gaskets that are the biggest downfall not bearing failures. An impeller breaks or intake gets clogged and the motor overheats. Often due to safety issues you are not able to turn it off in time to prevent damage. Perhaps some issues may be caused with rings and valve stems, but normally not fatal, just oil burning and extra smoke. I don't think the wear on these heavy duty low RPM engines is enough to justify the expense of synthetic as they are unlikely to see any benefit at all. Who really cares if the bearings are like new if what is likely to do the engine is a cracked head or block after an overheating incident.

I know I use synthetic on all of my personal cars. I had a Miata that was just shy of 200,000 miles when I sold it, but that is a very different scenario from a marine diesel. That was hard driven HIGH RPM use. I tracked the car, and auto crossed it so it would spend hours at a time at or near red line. I changed oil depending on use, about 8,000 miles of street use and after every track event. It did not burn or leak a drop of oil and I switched it to synthetic oil at around 70,000 miles. My BMW uses synthetic as factory recommended but I change it more than recommended. I drive about 18,000 a year and change it every six months. I just think 15,000 is to long to go without oil analysis. Since the analysis costs about the same as a change then it seems to me smarter to just change it because if it comes back as needing to be changed it costs twice as much (cost of analysis and cost of oil). Cars are a different animal, as they are not low RPM and light duty motors.

Sailboats with perhaps twice a year changes, is all they need for a long long life. Unless of course you have a Volvo, we all know they will blow up anytime!
10-06-2013 10:42 PM
Re: Frequency of Changing Oil & Fuel Filters

Sounds like a great topic for Practical Sailor to tackle.
10-06-2013 05:12 PM
Re: Frequency of Changing Oil & Fuel Filters

AFAIK the only real difference in synthetic oil is that the "oil" molecules are manufactured to a higher standard. However, since synthetics are usually sold as premium oils, they also usually carry a more expensive load of additives, and it is the additives that fight corrosion and do all sorts of other good things. Mobil1 contains a lot of moly (molybdenum disulphide?) which is an excellent metal-on-metal lubricant. Kendall is pushing some mystical titanium coating, claiming it titanium plates metals in the engine. But the stuff that fights acids, etc? Harder to quantify, but since they are pushing longer oil change durations, they would have to put in more additives to cover the longer oil change period. In theory.

More good reasons to do an oil analysis. It may run $25 a shot, but one baseline, and then one a year later to see if you need to change oil more often or less, isn't a bad investment considering how many oil changes or engine jobs it may save in the longer run. Anything else is basically shooting craps.
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