Pontoon Boat & Deck Boat Forum

I've been on a number of motorcycle/car/mechanical forums in the past and it seems that all have an oil thread. A place for guys to argue to know end about which oil is the best and why or why not to use a particular brand or viscosity. After searching I see no such thread here, so in my effort to raise some blood pressure and seek information I decided to start one.

My main question being I've read that you shouldn't use automotive oil in outboards because supposedly there are more vibrations and automotive oil will not meet the rigorous demands of an outboard engine, I think that I may have read this on an oil manufacturers website so... I think more than likely this is a bunch of bunk and automotive oil will be fine. I've run Mobil 1 full synthetic in most everything I've owned for years from automobiles, to motorcycles, to lawn mowers and it has served me well. My boat motor is a 2005 Mercury 115 4 stroke if that matters. Any reason not to run Mobil 1?

What kind of oil do you use? Any reason not to use automotive oil? Any oils that you have had bad experiences with?

Find an oil that meets the manf spec found either under the cowling or in your owner's manual. If an auto oil meets the spec then it meets the spec! I've used automotive oil in motorcycles for 30 plus years without issue... And like you I'm a fan for Mobil 1 too...

I'll continue to use Yamaha's oil because of the engine warranty. If something ever happens under warranty, I want their oil in it.

I am not against using a Mobil 1 after the warranty is out. I used it in my Harleys and all of my power equipment around the house.

ralph wrote:I'll continue to use Yamaha's oil because of the engine warranty. If something ever happens under warranty, I want their oil in it.

I am not against using a Mobil 1 after the warranty is out. I used it in my Harleys and all of my power equipment around the house.

Why? Yamaha can't void or deny warranty work based on brand of oil just the same as HD can't or Honda can't... As long as the oil meets the spec it meets the spec!

This is based on the Magnuson–Moss Warranty Act where the manf MUST prove that work performed or after market parts installed were the direct cause of the specific failure and/or claim...

Yep, people get way to involved with oil. 99% of mechanics I know don't even use synthetic. They don't think it's not good, they've just never seen issues with regular oil used properly. If it meets the specs, it meets the specs. Stop the insanity is the same thing. There you go, now oil natzis can argue.

The place to read about any lubrication is BobIsTheOilGuy.com.

I ran Delo heavy duty oil in my new pontoon boat after the first oil change, and it does great in any engine that doesn't have a catalytic converter. And it's relatively cheap.

Now, I'm running Mobil 1 EP--Extended Performance. It's far superior to plain old Mobil 1 in quality. Since I didn't run but 20 hours last year, I never bothered changing my oil. I will be changing the lower unit grease, however.

My Yamaha also gets a high quality oil filter--the same one that fits a 2.0 Ford Focus engine. It's the same thing Yamaha paints black and charges 3x the price of the mass auto parts stores.

As far as Mobil oil goes, if Exxon-Mobil spent the big money to have their products tested for marine applications, it would easily pass. But the marine retail market is a very small part of their business. Come to think of it, Exxon also makes the synthetic oils for Walmart's house brand.

I use Mobile 1 in everything except the Prowler. I use cheap synthetic wet clutch oil in it and cheap JAP filters, because its changed every 20 hours. It gets a real pounding and see's some high clutch temps! But the oil always dumps clean.

ron nh wrote:Yep, people get way to involved with oil. 99% of mechanics I know don't even use synthetic. They don't think it's not good, they've just never seen issues with regular oil used properly. If it meets the specs, it meets the specs. Stop the insanity is the same thing. There you go, now oil natzis can argue.

Hey, no argument here, to each his own. I just prefer the Yamaha oil. If something does happen to the engine, I just figure it takes any oil issue out of the equation immediately.

I've used Mobil 1 in my vehicles since 2001 since I had a conversation with an Manufacturing Engineer in the oil industry.

In fact, Mobil was in the 11th hour of an agreement to be the supplier to Harley for their synthetic oil. Mobil wanted to put their logo on the bottom side of the bottles (small logo). This was a deal breaker for Harley. They ended up giving the business to Citgo at the end of the day. This was why I didn't use the Harley brand synthetic because at that time (anyway), Citgo was owned by the dictators of Venezuela.

When we got our boat in Feb. 2008 I decided to do most of the regular maintenance myself. I cannot find where I saw the test but found that of a bunch of oils tested, Penzoil 10W40 got the best marks for preventing oxidation (rust) on iron. I'm not sure how much of the engine innards on our F225 Yammi are iron but I've been using it faithfully every since day one. As for all the other engines on our farm, I use Shell Rotella T 15W40. Tried the Synthetic T6 for a while but seems difficult to find near Willis and Conroe for some reason. Maybe most of the Red-Necks around here don't want to pay the premium for the T6.

Went with Mobil 1 10W-30 in the motor and Valvoline 90W80 in the gear box. The oil that came out of the crankcase was some of the nastiest oil I have ever seen. The previous owner supposedly had someone come out and change the oil each season. They either didn't change it or they sucked it out of the crankcase instead of using the drain plug and it left all of the oil with sediment in it in the bottom of the crankcase. It was chunky when I first pulled the plug. It also seemed pretty broken down. The gearbox had about half of the capacity that it should have had in it and it was very nasty and looked like it had a little bit of water in it as well. I went ahead and changed the waterpump impeller while I was at it, the one I took out had a 2006 date stamp on it (2005 motor) surprisingly though it didn't have much wear on it at all. How people spend that much money on a motor and neglect it like that is beyond me. The motor ran great when I pulled it out of the water back in the early winter. First time it's been out in nearly 10 years. I think it will run great and serve me well, I hope she appreciates the love I've given her.

ron nh wrote:Yep, people get way to involved with oil. 99% of mechanics I know don't even use synthetic. They don't think it's not good, they've just never seen issues with regular oil used properly. If it meets the specs, it meets the specs. Stop the insanity is the same thing. There you go, now oil natzis can argue.

I'm a Mechanic, and most of the guys I work with use Synthetic Back when I worked for a Cat dealer I had access to free oil testing so I decided to see how far I could push oil changes on my Supercharged Thunderbird. Using regular Dinosaur oil I could only go about 4,500 miles before the oil would go out of spec, Mobil 1 made it 17,000 miles before it was too DIRTY to continue using and was still "in spec". Been using Mobil one in EVERYTHING since and it actually costs about the same since I do 1/3 the oil changes, but I still spin on a new filter 1/2 was through. Cat doubles the service hours for oil changes if you use a full synthetic, that enough proof for me!

I have a 2016 Mercury 115. I too was curious about using Mobil 1 ?

Here's my "rub".. I can't seem to find a non-synthetic (dino), MARINE, 10w40. Everything around it, just not EXACTLY. Any ideas?
Thanks,
Sami ( I might just be stupid........)

[quote="SamiGuy"]Here's my "rub".. I can't seem to find a non-synthetic (dino), MARINE, 10w40. Everything around it, just not EXACTLY. Any ideas?
Thanks,
Sami ( I might just be stupid........)[/quote]

Just stumbled across this old post and wanted to comment that the Yamaha 4-stroke motor does not even have a recommendation for marine oil from the factory in that it list pure automotive oils in the Owner's Manual such as SE, SF, SG, SH, SJ and SL with SL being our most current oil spec... While I indeed used Yamaha oil for the first change from this point forward I'll likely use Mobil 1 full synthetic oil... While on the other hand Mercury does call for marine spec FC‑W oils...

More reason to use an FC-W motor oil.

http://www.boats.com/reviews/outboard-e ... YGJivHrtjo

I looked at Mobil's web site. I found no oil that meets this spec.