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10w-30 or 10w-40 for 04' AR230?

Vedner19

Jet Boat Junkie
Messages
122
Reaction score
67
Points
147
Location
Kissimmee, FL
Boat Make
Yamaha
Year
2003
Boat Model
SR
Boat Length
23
Ive always used 10w-30 on my Yamaha boats and that's what it recommends in the manual. I've read on here a lot of people are using 10w-40. Should I be using the 10w-40 too?
 
I run 10-30 synthetic Mobil 1. Synthetic degrades differently than regular oil and should be like a half life 10-40 dino oil.
I believe Yamaha suggest a synthetic blend which would give you benefits of both.
 
The 10W-40 and the 10W-30 are both what are called multi-weight oils. The number with the W is called the winter weight; the number after is the summer weight. The oil is measured at 0 degrees and at 212 degrees for each respective number. The higher the number, the thicker the oil at that temperature.

So, both oils are the same viscosity at low temperatures. However, the 40 weight is slightly thicker at higher temperatures. In a low-tolerance engine, the thicker weight is generally not needed because the distance between the parts is smaller, creating a seal that enhances lubrication. That said, if you are running at higher temperatures, then the 40 weight will not break down as quickly. In fact, at a higher temperature, the 40 weight oil will be the same thickness as the 30 weight at a lower temperature. But at equal temperatures, the 40 weight will be thicker and will require more force to move.

If your engine overheats, the 40 weight will protect it longer before breaking down. But under normal operating conditions for our engines, the temperature is controlled by the cooling system to not get too hot, no matter how hot it is outside. So I would stick with the 10W-30, but I doubt that you would really hurt anything by going to the 40 weight.
 
Our owners manuals specify Yamalube 4m FC-W which is 10w30. At some point the Yamaha oil change kits started to include 10w40. I believe Yamaha changed their recommendation at some point.

I use Mobil 1 10w30 in mine.
 
The 10W-40 and the 10W-30 are both what are called multi-weight oils. The number with the W is called the winter weight; the number after is the summer weight. The oil is measured at 0 degrees and at 212 degrees for each respective number. The higher the number, the thicker the oil at that temperature.

So, both oils are the same viscosity at low temperatures. However, the 40 weight is slightly thicker at higher temperatures. In a low-tolerance engine, the thicker weight is generally not needed because the distance between the parts is smaller, creating a seal that enhances lubrication. That said, if you are running at higher temperatures, then the 40 weight will not break down as quickly. In fact, at a higher temperature, the 40 weight oil will be the same thickness as the 30 weight at a lower temperature. But at equal temperatures, the 40 weight will be thicker and will require more force to move.

If your engine overheats, the 40 weight will protect it longer before breaking down. But under normal operating conditions for our engines, the temperature is controlled by the cooling system to not get too hot, no matter how hot it is outside. So I would stick with the 10W-30, but I doubt that you would really hurt anything by going to the 40 weight.
WOW that was a good lesson for me in oil. I never knew about the summer/winter thing and the specific temps. sincerely THANKS!
 
These motors would probably run forever on cheap walmart oil and you'd never know the difference,,, until disasembly of course. We use 10/40 as a standard. since all the 4-strokes are basically flat tappet engines., If your concerned, i recommend getting an oil with an EXTERMELY stout additive pack. Generally the newer the oil the less of these "wear protecting" metals ( zinc/phosphorus/magnesium ) are in the oil due to meeting emission standards.
 
These motors would probably run forever on cheap walmart oil and you'd never know the difference,,, until disasembly of course. We use 10/40 as a standard. since all the 4-strokes are basically flat tappet engines., If your concerned, i recommend getting an oil with an EXTERMELY stout additive pack. Generally the newer the oil the less of these "wear protecting" metals ( zinc/phosphorus/magnesium ) are in the oil due to meeting emission standards.
So what do you think of a synthetic or synthetic blend? Mobil1? Castrol gtx?
 
Full synthetic 10-40 is what Yamaha recommends for the 1.8 ho and sho. Same as for crotch rockets. The down side is that it is very expensive in comparison to standard 10w30. O'reilly store brand seems to be the cheapest of the 10w40 full syn. Can't image too many places making that stuff so likey whoever makes it for them switches bottling line for another name brand. You can also find 6 pack deals onlie for the name brand stuff. I am careful to use oil that meets the manual specs and record proof for my extended warranty.

I am not a molecular scientist but something about using a full syn 10w40 in a high compression, high rev operating range engine just makes sense. But if I am being suckered into paying too much for oil please do let me know.
 
Some drink "home depot" Vodka, Some drink Grey Goose., you have your entry level and you have your top shelf... With oils you "usually" get what you pay for,,, usually. I not a fan of companies that 1/2 the price of the oil goes toward paying for the advertising and promoting the brand vs the quality of the oil. ( no names )...
Personally, Im pretty fanatic about oil, so I tend to run extremely quality oil in my stuff. I'm a dealer and can get almost any of the top motorsports and marine oil brands out there, meaning I can choose and run pretty much anything. I don't own a 4-stroke jetboat, but in my Yamaha Apex 4-stroke snowmobile I run this:
KE-830.png
 
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I have used Mobile 1 synthetic 0w-30

figured since mostly we have a cold start and almost immediate throttle given before fully warming up, lighter weight when its cold should theoretically protect the engine better.
 
During break in period, I would think you want to stick with the mineral oil 10w30 so the engine can properly break in. But after that, it never hurts an engine to go full synthetic as it provides better protection. Manufactures will always recommend the least they can for customers. Hence mineral oil which is basic natural occurring oil. Fully synthetic will protect the engines more in the long haul after properly breaking in the boat. IMO. I will be going full synthetic this spring when another oil change after running the engines for a day or so.
 
What would be better here?

Castrol 06246 EDGE 10W-40 SPT

Castrol 06112 Power1 10W-40 Synthetic 4T Motorcycle Oil
 
@Vedner19
I have converted to 10w-40 because the 'low oil pressure' switch on the MR-1 engines will turn on at idle once the engine is hot. This can be seen while the YDS is connected but it will not translate to an indicator light or stored alarm. I also believe that Yamaha changed the recommended weight somewhere around 2010 from 10w-30 to 10w-40.
 
Yamalube is great for break-in. Many Yamaha ski racers like Amsoil 10W-40 Synthetic Marine 4-stroke. I have switched to that, too. Seems great, once the engine is broken-in. Or buy from @ISLANDRACING if you want the very best!

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