Should I use synthetic?

[Damon]

Okay- the last post steered me towards 15-40, the same grade I use in my diesel truck. I there any reason to use the Amsoil that I used last year? What about using a good Delo 400 and a Napa filter? I know the amsoil is good, but is it really worth the extra $25.00?
Keep in mind that I change my engine oil after about 35 hours, but could easily change it more often (I have an electric onboard change pump), and I run it at or near redline frequently.

What do you think? Delo 400 petroleum, or a full synthetic? What about the Delovac or whatever the Chevron full sythetic is?

1987 OMC 3.0 4 cyl. (old GM pushrod 4 cylinder)

 

[Steve S]

The delo or delvac would do a good job unless the oil runs way hot or the boat is started in freezing weather, well you won't go wrong with the heavy duty oils ,Amsoil 15w40 works good.Iam at a point where I think $25.00 for gas or for oil that probably won't make a bit of difference . Well for me a blower or $4,000 or gas. Can't help it .Also the engine is neat they're used in alot of forklifts I like them.

[ April 13, 2003, 11:45 PM: Message edited by: Steve S ]

 

[Drstressor]

With 35 hr oil changes, wouldn’t a racing rated oil make more sense for your application? Marine engines operated close to redline speeds are under very heavy load yet they really whip up the oil. The main considerations should be film strength (high viscosity and shear resistance), a robust EP additive package, and good anti-foam properties. Heavy duty diesel oils are great for most marine applications where engines are run at moderate rpm. They meet the first 2 considerations, plus the high initial TBN give good corrosion protection during storage. But I don't know about their anti-foam properties. Changing oil as often as you do, corrosion protection and detergency (the weakness of racing grade oils) should not be a factor.

 

[Steve S]

Heavy duty fleet oils are ideal for marine engines they have very high additive levels . they will protect at all rpms and are tops at foaming protection ,only the premium petro and syn oils will do a better job and are not necessary in your application as your motor is stock ? No need for more protection.

 

[Justin]

quote:

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Originally posted by Damon:
Okay- the last post steered me towards 15-40, the same grade I use in my diesel truck. I there any reason to use the Amsoil that I used last year? What about using a good Delo 400 and a Napa filter? I know the amsoil is good, but is it really worth the extra $25.00?
Keep in mind that I change my engine oil after about 35 hours, but could easily change it more often (I have an electric onboard change pump), and I run it at or near redline frequently.

What do you think? Delo 400 petroleum, or a full synthetic? What about the Delvac or whatever the Chevron full sythetic is?

1987 OMC 3.0 4 cyl. (old GM pushrod 4 cylinder)

---

I've always used HDMO's, usually Delo 400, but Delvac 1300 and Rotella-T are also good (many say Rotella is not as good, but I've seen all sorts of equipment last a very, very long time on just Rotella.

Personally, I'd go with one of the HDMO's. They do a great job (protect exceptionally well), and for $6 a gallon, you can't beat the price for what your getting.

Like you mentioned, if you use one of these HDMO's, just change the oil on schedule, and don't push it just to get a little more mileage out of it.

On the other hand, if you like synthetics, then by all means, go that route. They are exceptional oils...
Justin.

[ April 17, 2003, 12:25 AM: Message edited by: Justin ]

 

[msparks]

quote:

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Originally posted by Damon:
I there any reason to use the Amsoil that I used last year? What about using a good Delo 400 and a Napa filter? I know the amsoil is good, but is it really worth the extra $25.00?
Keep in mind that I change my engine oil after about 35 hours, but could easily change it more often (I have an electric onboard change pump), and I run it at or near redline frequently.

1987 OMC 3.0 4 cyl. (old GM pushrod 4 cylinder)

---

Here is Amsoil's Oil change interval recommendation sheet.
http://www.amsoil.com/lit/g1490.pdf

For boats, Amsoil recommends that you can go 3 times longer or 1 year when using the 15w40(AME) over a conventional lube.

Also most of the recommendations on that page are very conservative.

If you feel uncomfortable with these drains, I would use Oil analysis to determine a drain interval.

For instance, at 35 hrs on your boat with Amsoil. Take a sample. It will let you know if you can extend out.

If you have any questions let me know.

Michael