1993 Echelon 350 Original Oil Recommendation

[drdave88]

I know everyone has their own preference of oil, I'm the type of guy that tends to stick to what the manufacturer recommends. I cant seem to find the manual that came with my boat when I bought it, so can someone tell me what Malibu originally recommended for oil in a 350 Mercruiser? I hear all kinds of recommendations from 5w40 to 10w30 to 25w40 to straight 30. I live in east Michigan and it gets run for a few hours a weekend from May/June to Sept/Oct. Its mainly used for just cruising or tubing on smaller lakes. It seems 25w40 isnt the cheapest oil out there, and I dont think that was around 20 years ago.

What was the original oil recommended, and is there a common oil that most run in this area? This engine only has about 430 hours on it, not sure if that makes a difference.

[Woodski]

The manuals are on this site, surf around & you will find them. I would recommend sticking with what you have been using, it seems to be working for you. You don't or won't see extreme temperatures so you can use lower viscosity oil compared to hotter climates. First criteria will be if you want synthetic or not, then viscosity will be your other choice.

[nuttyskier2002]

I owned a '95 Echelon from early 2007 'til late 2011. I did receive the owner's manual from the previous owner. Mercury Marine calls for Quicksilver 25W40 in all of their 4 stroke cycle engines. When I was buying this stuff it was about $25.00/gal at Bass Pro Shops. I haven't priced it since selling this boat but I'll bet it's quite a bit higher. I now use Valvoline Premium Blue 15W40 as I believe it is every bit as good as Quicksilver. The Valvoline is only ~$12.00/gal as opposed to 25. One thing to consider.......you can bet Mercury Marine collects royalties on every Quicksilver product that passes over the counter. Thus the reason for pushing it so hard.

[drdave88]

This is my first time changing the oil in it so I havent used anything yet. Having an automotive background, and knowing the typical chevy small blocks, i would think 10w30 would be ok. But since this is a marine application, i know the engine runs differently. So would i be better off sticking with something closer to a diesel oil (15w40) or a typical gas engine oil, or would straight 30w be ok?

[MalibuBnut]

I roll with rotella 15w40. Every 50 hours or less I change oil and filter.

[nuttyskier2002]

Many people here use 15W40 "diesel" motor oils as I do. I personally believe that 10W30 is on the "light side of things" when it comes to "thickness". Our engines run under constant load and never "coast" like automobile engines do. More load means higher pressure between rod bearings and crankshaft journels.

[MalibuBnut]

I'm sure if you run mobile one that would be fine too. I always run mobile one in everything except the Malibu. I have a buddy that runs mobile for 3000 miles in his gsxr 1000 then he drains it and puts it in his van. Lmao it works fine I guess his van has 240,000 miles.

[JasonK]

Mercruiser recommeded 25w40 when the boat was new.

[j.robinson389]

From the Mercruiser Service Manual #17, it states SAE 40W when operation in temperatures over 50°F. If someones needs a full .pdf copy of this manual let me know.

Edited July 5, 2013 by j.robinson389