Synthetic Automotive oil vs Marine 10w40 amsoil.

[direct]

Looking to use Castrol or Mobil 5w40 Synthetic oil in the Ultra 250x.

10w40 is what's recommended and Amsoil works for that.


Anybody has used automotive synthetic oil? I've used it in my boat, rather than marine oil and have no problems. Synthetic automotive oil goes on sale constantly.

[arctic388]

I plan to use Rotella T6 5w40 in my Seadoo GTI's. you should be good with any good syn oil just keep it changed regularly.

[diegoo.jayjay]

Look at Maxima ProPlus or even Extra.

[imp0ster]

I promise you it doesn't matter. Change it regularly and stick with the viscosity the dealer recommends.

[direct]

Just found this oil. Kawi recomends x w40 but this one's w50, yet as it says it's a full racing oil for constant high rpm. https://www.amsoil.com/shop/by-produ...code=RD50QT-EA

Amsoil Dominator

[direct]

I plan to use Rotella T6 5w40 in my Seadoo GTI's. you should be good with any good syn oil just keep it changed regularly.

We use that in our diesel trucks that are always maxed out on load. Works great with no issues... May turn to this as well seeing how it handles high loads.

[cjk6119]

Looking to use Castrol or Mobil 5w40 Synthetic oil in the Ultra 250x.

10w40 is what's recommended and Amsoil works for that.


Anybody has used automotive synthetic oil? I've used it in my boat, rather than marine oil and have no problems. Synthetic automotive oil goes on sale constantly.

2018 FX-SVHO 103 hours on original clutch using Mobil 0w40 synthetic or Amsoil from day one, no oil leaks at all.
Take Care
CJ

[Myself]

I've been using Rotella T6 5w40 and 15w40 in all my customers skis for a few years now. I also run it in everything I own from my pushmower to my wife's 200,000 mile F150. Goes on sale for $22 a gallon. I have one customer with 2 Ultra 250's and 2 Ultra 310's and Rotella is in all of them.

[Pacer]

I use T6 in my wife’s ecodiesel Jeep, my dodge 2500 5.9 diesel, and my Ram ecodiesel, and all my skis. The only thing I don’t use it in is my Jetta TDI.

[TimeBandit]

OTA !! (Oil Thread Alert)

I promise you it doesn't matter. Change it regularly and stick with the viscosity the dealer recommends.

Generally agree -- “it doesn’t matter as long as you change it regularly”

Synthetic’s (pao4 oil) only true benefit (and it is a pretty good benefit) is not having to be as loaded-up with VIs (viscosity inhibitors) as conventional oils are. Simply-put ... consider your 10W-40 product, VI's magically permit a 10 weight base oil to function like a 40 weight oil at engine-temps.
Because Synthetics viscosity is less reactive to temps, their base oil is closer to that actual 40 weight.

So if a true 40w synthetic AND a conventional 10W (with VIs) behave the same at room and engine temps, then why go with one over the other ??? Cost is one factor, yet the real factor is “time”. VI chemicals are fragile - relatively speaking - and basically get crushed inside the engine components. As time goes on, that conventional 10W oil begin to lose its 40w magical abilities - hence why regular & frequent changes are required.

So what’s the math here :
- If you religiously change your oil according to conventional intervals - you are 100% wasting your money on synthetics.
- However.... if you are the procrastinating-type, and often go past your change intervals, a good synthetic can offer you that added piece-o-mind