Which type of Motor Oil?

[Tiara 3100]

I am about to change the oil in my new to me 1991 Tiara 31 Open, the boat has twin 7.4 ltr Mercruiser engines. I typically run 4-10 miles to fish and then troll on one engine (rotating every couple of hours). My question is what is the opinion on which oil will give my engines the best protection over the next several years? It has 1200 hours now and the previous owner never fished it, it was only used for cruising and is in 9 out of 10 condition.

Thanks!!

[yottyboy]

SAE 30. Napa has it on the shelf. Change it regularly. You don't need anything fancy like synthetic.

[Tiara 3100]

Thanks!!

Any other opinions????

[geronimo]

Good oil is a great investment in your engine. Dont skimp on oil. Find other places to save money. make sure you use oil that meets Merc standards , but , more important ,,meets your standards for temp in your area, and heat of your engine. Synthetics are a safe bet.

[Baytro23]

When your motor was new Mercruiser did recommend the straight 30 wt. They didn't want viscosity improvers in there to break down and cause buildup. They now recommend for all their motors (old and new) their quicksilver 25w40. It has no viscosity improvers and doesn't break down under heat and load.

[Capt Rick Hiott]

They dont make any better! http://www.valvoline.com/

My dad used it in his race car for many years and I have used it for the last 35 years.