25w-40 oil

[Dom08]

Hello all



I have a 03 outback

I found some 25w-40 marine oil as 10w-40 marine is hard to come by right now.
our location as it gets up to 30-40 degrees outside and the boat sits in the sun

Should this be fine?

[bergermaister]

Never heard of 25w40, unless that was a typo. I have used Shell Rotella 15w40 for many years with zero issues from 34 degree winter surfing to 115 degree summer rides.

[Holdmybeer]

Dom,
When you say 30-40* you are talking C, correct so 100-105*F

25w40 is rare for the US but not sure about availability in other parts.
10w40 wouldn't scare me or hurt anything. What engine do you have in your outback.

Is it the 325? If so, it based of the 92-95 GM truck 350 block. Factory is 10w30 for the truck. The old 5.7 motors were hard to break so I wouldn't be worried. Watch your oil pressure though. Hot motor should be 10psi oil pressure for every 1000rpm minimum. Idle should be close to 20psi all the time and then go up from there.

[Dom08]

Here is the oil link

https://www.lucasoil.ca/products/4-stroke-marine-engine-oil-sae-25w-40/

[Holdmybeer]

That is stern drive gear oil.
Please don't put that in your engine.

Indmar engine manual for 2003 is Pennsoil 15w40. It is hard to find.

Where are you located? I'll try to help you source local or at least have shipping to you.

[Holdmybeer]

Try this 1

https://www.amsoil.com/p/amsoil-15w-40-heavy-duty-diesel-and-marine-oil-ame/?code=AME1G-CA&gad_source=1&gad_campaignid=20711131335&gbraid=0AAAAAD4pZOgvigU97BEcd4pXbgLx5k2gZ&gclid=Cj0KCQjwgIXCBhDBARIsAELC9ZgtrtWbaM5o6cp-ChMZerHnHscwJTR8TAtrKm-ahCkw3oKlaypzRrYaAv6iEALw_wcB

[Dom08]

What about a Rotella T5 Synthetic Blend 15W-40 Diesel Engine

[Dom08]

That is stern drive gear oil.
Please don't put that in your engine.

Indmar engine manual for 2003 is Pennsoil 15w40. It is hard to find.

Where are you located? I'll try to help you source local or at least have shipping to you.


It specifies marine engine oil... i don't see stern oil anywhere on the container
What about a Rotella T5 Synthetic Blend 15W-40 Diesel Engine

[Holdmybeer]

Rotella meets CJ4 CI4 AND CI4+ but not SL/SJ because it is diesel oil.

C = Compression engine (diesel)
S = Spark engine (gas)

But yes it would work and has zinc in it for flat tappet lifters.

[Dom08]

Ok, I'll give that a shot. Really appreciate the help

[MJHSupra]

What about a Rotella T5 Synthetic Blend 15W-40 Diesel Engine

T4 or T5 are good choices.