Amsoil SS 5w30 - Is it really "Resource Conserving"

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102
Location
NY
When I purchased my 2019 STI I was told to avoid resource conserving oils which due to the engine (EJ257) makes sense. I am looking at trying out Amsoil SS 5w30 which has Resource Conserving listed on the compatibility section.

"W-30 (ASL): API SP (Resource Conserving), SN PLUS, SN GM dexos1 Gen 2 (supersedes LL-A-025, 6094M and 4718M); ACEA A5/B5, A1/B1; Honda HTO-06; Ford WSS-M2C946-B1, WSS-M2C946-A, WSS-M2C929-A; Chrysler MS-6395; ILSAC GF-6A, GF-5, GF-4"

As Amsoil SS is their top of the line oil does the previous advice of avoiding RC oil apply here? @Pablo ?
 
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2,131
Location
WA
What is the definition of "Resource Conserving"? Does that mean a thinner oil (relative to non-RS) at operating temps? Can it be resolved by moving up a grade or using the 10W30?
 

c5z06

Thread starter
Messages
102
Location
NY
What is the definition of "Resource Conserving"? Does that mean a thinner oil (relative to non-RS) at operating temps? Can it be resolved by moving up a grade or using the 10W30?

To be honest I have no idea what makes an oil resource conserving. I want to stay with 5w30 for warranty purposes.
 
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2,131
Location
WA
Good idea.

iirc, RC means thin oils like xW20's and maybe some thinner xW30's with lower hths ... Just guessing here since I don't pay attention to it and don't use any thin oil like xW20 or any low hths oils.
 
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16,647
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Upper Midwest
The definition of Resource Conserving oil is outlined in API 1509. It's more than just the viscosity, back in the day when it was classified as "Energy Conserving" that was the primary criteria.

"API Service SP engine oils designated as Resource Conserving are formulated to help improve fuel economy and protect vehicle emission system components in passenger cars, sport utility vehicles, vans, and light-duty trucks powered by gasoline engines. These oils have demonstrated a fuel economy improvement (FEI) in a specific sequence test at the percentages listed in Table 1 when compared with a baseline oil (BL). Additionally, these oils have demonstrated in other tests listed in Table 1 that they provide greater emission system and turbocharger protection and help protect engines when operating on ethanol-containing fuels up to E85.

Many previous S Categories made reference to “Energy Conserving,” but this reflected an emphasis on fuel-economy performance alone. Resource Conserving in conjunction with API SP focuses on fuel economy, emission system and turbocharger protection, and compatibility with ethanol-containing fuel up to E85.

Starting May 1, 2020, oils that have passed the tests at the limits shown in Table 1 and are properly licensed by API may display “Resource Conserving” in the lower portion of the API Service Symbol in conjunction with API Service SP in the upper portion. The fuel economy and other resource conserving benefits obtained by individual vehicle operators using engine oils labeled Resource Conserving may differ because of many factors, including the type of vehicle and engine, engine manufacturing variables, the mechanical condition and maintenance of the engine, oil that has been previously used, operating conditions, and driving habits. Before the May 1, 2020, introduction date, oil marketers may license oils meeting Resource Conserving in conjunction with API Service SP as Resource Conserving in conjunction with API Service SN."
 
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Messages
2,131
Location
WA
I know Amsoil SS has high hths because I researched their 10W30. Just remembered that A5 B5 stuff are RC.
You may need a3/b4 type of oil with higher hths.
 

c5z06

Thread starter
Messages
102
Location
NY
So the classic European sports car oil would be more inline with what I need if I picked from the Amsoil line then?
 
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2,494
Location
NJ
As madeej11 mentioned, Amsoil SS 5W-30 has an HTHS of 3.11 which is the same as typical RC oils. Go with an HTHS of 3.5 or higher for a more shear stable oil. For Amsoil, yes, you’d be looking at the European formula. It’s reduced SAPS, which is not much benefit in an STI though. I’d keep the intervals short.

Amsoil XL 5W-30 does have a high-ish HTHS of 3.3, IIRC, which is the upper end of RC oils (can’t check the site at the moment).

Presume that you are not planning any mods?
 
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16,647
Location
Upper Midwest
Considering your criteria, why don't you just go to Walmart and get either Castrol or Mobil 1 0W-40 for about $5 a quart? It has the HTHS you're looking for plus proven performance in having Porsche A40 and Mercedes-Benz 229.5 approvals as well as ACEA A3/B4. It would be difficult to find an oil with better demonstrated performance at that price (or any price).
 

c5z06

Thread starter
Messages
102
Location
NY
As madeej11 mentioned, Amsoil SS 5W-30 has an HTHS of 3.11 which is the same as typical RC oils. Go with an HTHS of 3.5 or higher for a more shear stable oil. For Amsoil, yes, you’d be looking at the European formula. It’s reduced SAPS, which is not much benefit in an STI though. I’d keep the intervals short.

Amsoil XL 5W-30 does have a high-ish HTHS of 3.3, IIRC, which is the upper end of RC oils (can’t check the site at the moment).

Presume that you are not planning any mods?

More mods once out of warranty (AOS, axleback, oil pressure/temp gauges don’t count) and then I’ll run a 40wt oil. Probably going to look at Valvoline Euro 5w30 or stick with Pennzoil Euro L. Overall was curious about Amsoil.
 

c5z06

Thread starter
Messages
102
Location
NY
Considering your criteria, why don't you just go to Walmart and get either Castrol or Mobil 1 0W-40 for about $5 a quart? It has the HTHS you're looking for plus proven performance in having Porsche A40 and Mercedes-Benz 229.5 approvals as well as ACEA A3/B4. It would be difficult to find an oil with better demonstrated performance at that price (or any price).

sticking with 5w30 until the warranty is up at the 3 year mark and then I’m going 40wt for sure.
 
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2,494
Location
NJ
sticking with 5w30 until the warranty is up at the 3 year mark and then I’m going 40wt for sure.
Did you see on the temp chart in your owner’s manual where they show 5W-40 as well as stating that a thicker viscosity is required in high temps?

3FA2C45A-6178-402A-A8A3-7F376FEAF218.jpeg
 
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2,131
Location
WA
seems like most owner's manual find a way to list a thicker grade after they list the thin and/or RC grade.

Your engine will like you if you read that page! :)
 

c5z06

Thread starter
Messages
102
Location
NY
Did you see on the temp chart in your owner’s manual where they show 5W-40 as well as stating that a thicker viscosity is required in high temps?

View attachment 25230
hmm I do see that but I read it as 5w40 only if 5w30 isn't available, however I do see the in hot weather comment. So much wiggle room in the manual, I wonder how much they (Subaru) would actually fight the use of 5w40. IIRC they would have to prove the oil weight caused the issue correct?
 
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