Using Synthetic longer

[Mytoolguy]

Did a search but couldn't find anyone that asked this question.

2014 F300
Manual states can use regular dino oil or synthetic.
Also recommends oil change every 100 hours.

If using Synthetic does anyone wait a longer period of time to do the oil change.
Kind of like in a car they recommend every 3K but synthetic is every 7500 - 10K miles.

Not being cheap but if SYN can go longer why not wait to 150 hours or so?
If not then why would anyone use anything but dino oil and just change the 100 hours as recommended.?

if there is a thread on this please post a link.

[DennisG01]

Does your manual say every 100 hours or once a season? Even if it doesn't I wouldn't go longer than a year as there's a possibility of moisture and impurities buildup.

[Mytoolguy]

Does your manual say every 100 hours or once a season? Even if it doesn't I wouldn't go longer than a year as there's a possibility of moisture and impurities buildup.

Not worried about once a season as I put more than 100 hours and the boat lives in San Diego on a trailer so no issues with extreme temp changes or in a saltwater environment 100% of the time.

Its just weird how they can recommend both dino and SYN oils but they supposedly have the same life span? If that were the case why would anyone buy more expensive oil and just get the regular non-syn and do the oil changes every 100 as recommended.

[99yam40]

running a motor often is best for it.
how many hours a year do you run yours?

if it is 150, I would let it go that long and change at the end of the season before putting it away.

Checking the oil level and condition often during the year is a very good idea to catch any out of ordinary things going on.
like making oil, loosing oil , or water intrusion

[oldmako69]

I wouldn't lose a nights sleep over it if I were in your shoes. Change it once a season and run the hell out of it. Oil change intervals are idiotic. 100 hours and it's done? It's just an arbitrary number. Todays engine oils are light years ahead of the ones our fathers ran. What was the oil change interval then? 100 hours.

[Mytoolguy]

running a motor often is best for it.
how many hours a year do you run yours?

if it is 150, I would let it go that long and change at the end of the season before putting it away.

Checking the oil level and condition often during the year is a very good idea to catch any out of ordinary things going on.
like making oil, loosing oil , or water intrusion

I typically use my boat all year round being in San Diego & watch my fluids.
I do get the hours thing to a point. On diesel trucks oil changes are also done on e hours as well because of the idle time. The 1 hour is = to 35 miles.
I am a big proponent of maintenance. Just not when it is overkill.
Thanks for the replies

[DennisG01]

The "thought" is that the synthetic is better for the engine - at startup and resistance to breaking down. Less about the amount of hours, per se. I'm sure there's more to it than that, but I think that's the "jist" of why synthetic is better.

Now, that said, I absolutely wouldn't be concerned (and in real life practice, I am not) running dino oil. I do run synthetic in my 2-strokes, but that's more because I tend to get less smoke that way.

[oldmako69]

Years ago I went to an Amzoil presentation. One of the things they claimed which piqued my interest was that synthetics carry dirt in suspension MUCH better than dino oils. And because of that, they carry more dirt to the filter than dino oil. They also said that Amzoil filters were much finer mesh and captured smaller crap. And because of all this, the engine will produce less sludge.

True? I dunno.

I later spoke with a machinist at a high-end shop that specialized in Porsche engines. He said that synthetics were superior in the way they adhered to vertical surfaces (think cylinder walls on a traditional car engine) and offered superior lubrication during start-ups. He also said that they were inferior to Dino oil where hard met hard (think of pushrods against cam followers or lobes).

I'm lazy. I run synthetics so I can drag out the oil change interval in my cars. I don't worry if I go over for whatever reason. Except for my old diesel. That gets whatever diesel oil I can find on sale and gets changed often.

The boat gets changed annually, irrespective of hours. When I ran a single inboard I'd routinely put over 200 hours on a big dumb v8 per season. Gas was cheap and I was a fishing lunatic. A 351 can take an amazing amount of abuse.

[brian3006]

I have been running synthetic oil ( Yamalube gold bottle)in all my Yamahas. I have one boat with twin F300's We put well over 100hrs on it a year. Due to Scheduling, I can not always change it at the 100 hr mark. I have gone to 160 or so hrs before and the oil still looked pretty good. the boat gets run in all temps from 100* in July to 20* breaking ice in the creeks...that is why I prefer a synthetic oil. I also run the boat hard... Even on the boats I do not put 100hrs on, I will change the oil annually... I think you will be perfectly fine to extend the oil drain interval. most importantly keep a check on the levels and the condition of it periodically..

[HMBJack]

I would think (?) you could go to 200 hours with synthetic no problem.
Only way to be sure - is have a sample of your synthetic oil analyzed by a Oil Lab after 100 hours or so.
These Oil Labs are out there and can answer your question without being too costly.