Corrrect oil? 3.0 Mercruiser 1989

[punthouse]

Thought my manual said 40W but the filler cap on the engine says 10W40. Big deal? Thanks for your time.

 

[Bondo]

Re: Corrrect oil? 3.0 Mercruiser 1989

Look Here......<br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=005225

 

[dhammann]

Re: Corrrect oil? 3.0 Mercruiser 1989

Application, application....the GM 3.0 was designed for many uses other than marine. For your application 30wt is recommended. 30wt is pure oil...multigrade is an addidive laden oil (viscosity improvers)used to compromise a wide range of conditions. If you don;t need it,then you are better off not using it! Multigrade addives are noted for sticking rings...unless you use your boat frequently in cold weather don't use it!!

 

[Walt T]

Re: Corrrect oil? 3.0 Mercruiser 1989

How often you service it is more important than what you use. Keep it simple.

 

[bluewater19]

Re: Corrrect oil? 3.0 Mercruiser 1989

I have been running delo 15W40 in my 1991 and mercruiser motor oil in my 2003. As soon as my waranty is up I am going to change to full synthetic. I have used synthetic in our gmc suburban 93k miles,our chevy caprice 168k miles, and my wifes honda civic, 273k miles. after switching I saw no magic gains like the adds say although I have noticed that there is no varnish on the valve train and the oil always comes out looking the same as when it went in. I use castrol syntec. Change oil 7500-10,000 miles. I will continue to change the oil in my boat in march, july and november. I know it says to only change every six months but I like to use my boats alot!! I figure a little time and oil is cheap insurance.

 

[LubeDude]

Re: Corrrect oil? 3.0 Mercruiser 1989

Bluewater19:<br /><br />Only problem is that you fell into the Castrol marketing scheme many others have fallen into!<br /><br />Castrol Syntec "isnt" a Synthetic! Its a group III oil and not a true synthetic! Ya, the law says they can call it one, but its really not! It is a good oil. but it bothers me when someone is paying synthetic price for a Non synthetic product! Also youre pushing it with 7500-10,000 drain intervals with this product! Honestly your Chevron Dello 400 is nearly as good and is less than half the price! The ISO SYN means it is a Hdrocracked petrolium, high quality group II, which is what Castrol Syntec is, only it is a group III!<br /><br />If you really want a synthetic, use Mobil1, Valvoline, or Amsoil!

 

[bluewater19]

Re: Corrrect oil? 3.0 Mercruiser 1989

Wow I had no idea I was having the screws put to me. That is a pretty messed up marketing ploy. I guess I will have to switch brands.

 

[LubeDude]

Re: Corrrect oil? 3.0 Mercruiser 1989

Dont feel too bad, You certanly are not the only one! Like I said, Its a very good oil, It shows some very good UOAS, (Used Oil Analysis), I just cant see paying the price for a synthetic and not getting all the benifits of one! For instance you could go that far between changes with say Mobil1, better to go with the 7500, and even longer with Amsoil!