Oil for 5.7 MP

[SBM1234]

Hello all, this is my first post on here and have to say that this forum is awesome! You guys are so helpful to a newbie owner like myself.

Ok so here is the question, I have a 2007 22ve that I bought a couple of months ago. The prior owner took great care of it - expect for not winterizing it one year and had to replace the engine as a result. Anyway, it is time for me to change the oil. I look at the marine power owner's manual and they say to not use multi-vis oils like 15W-40 - they say to use straight 30W up to 50 degrees and 40w above 50 degrees. Well, I live in Houston so I figure the 40w is the one to chose.

But, I am wondering if this is correct? I mean companies use multi-vis oils in everything these days. Is there a reson to go back to straight 40w? Sure its great for a lawnmower, but a Vortec engine?

Thanks for the help!

[skippabcool]

Welcome to the site. You need to post some pics of your boat.

I have the same boat and asked the same question. You will get lots of different answers. For the last two years I have used synthetic 10w-30 without any issues.

You will see different opinions on Synthetic, Conventional, and blend. As well as different weights.

A popular weight is 15w-40.

[skippabcool]

I searched and found the thread that I started - http://www.tigeowners.com//forum/showthread.php?t=14466

[chpthril]

If you only used your boat in the dead of the TX summer, then a straight weight would be fine. But if you are like a lot of tow boat owners, you try to get as much out of a season as you can. This means starting early spring and running well into the fall, if not going year 'round. IMO, the multi-vis offers easier pumpability and better lubrication for those times the engine is started when the air and water temps are cool.

[SBM1234]

In all of my "land-based" motors (like my pickup, wife's car, lawnmower, etc.) I use Lucas Oil Stabilizer. Think that would be okay to use with a marine engine?

Thanks for the help guys! I just want to make sure I use the right stuff - I freakin' love this boat!

[chpthril]

Yes, the internal workings of a boat engine is no different that that of its street counterpart.

[NICKYPOO]

I've been running 10w-30 synthetic for years. Never had any issues.

[dom w. forte]

There can be more wear with straight weight unless you live in a region that has a steady temperature range which would be highly unlikely, multi weight covers a larger temp. range, so if its cold out the oil is thinner thus flowing better as engine warms up, if its warm out the oil is thicker for better surface protection, so you have to pick an oil which best serves your region, here in Fla. we have a much more warmer humid climate and need 15w 40.
As to synthetic vs a blend we have had these disscusions before, and all will be personal opinion, for our shop synthetic is great for all engines that are used on a regular basis, for those vehicles that are limited used they tend cause more internal wear because the oil doesnt leave as good of a surface protection for start up after a long no run period, also synthetics claim to fame is you can extend your service period, dont violate the manufactures recomened service time in either miles or hours, they have more testing time on their engines then any oil brand.
We reccomend service on the boats has every 50hrs or six months due to our high hunidity.