Owners Manual Oil Anomaly
 

Hi all. So I think I found what could be a mistake. Some background info on this:

So I was calling Toyota to ensure that getting my next summer oil change in 5W-30 will not void the warranty. I used the text on page 381 in the Subaru owners manual (Thanks to *Axel from his thread: https://www.ft86club.com/forums/show...=owners+manual)

It states higher viscosity is required at high temps, so it says you can use 5W-30 oil.

Here is the anomaly: The Toyota rep told me that she doesn't see that, in fact, she sees "5W-20" in the Toyota owners manual, on the same page.

That makes no sense.
1. Both owners manuals should be the same regarding the engine....they are the same engine!!
2. Even if there's something different, the whole point of changing the oil (as the owners manual is literally stating) is for higher temps... It's the second number that describes oil behavior at higher temps.

Right? 5W-20 and 0W-20 will have the same behavior at higher temps.

So, do you think it's a mistake on Toyota's part? Shouldn't it say 5W-30 like Subaru states, and not 5W-20?

It's not an anomaly - it's a different manufacturer having a different opinion on what is acceptable. Subaru may not see the need to confuse customers and potentially have them worry that they are not choosing the correct application for their needs, causing more support work for them.



It could also be that the oils used differ enough that Toyota's recommendation changes

The Subaru manual states 5w-30 conventional oil. Not synthetic oil as stated for 0w-20. Would not expect 5w30 conventional to out perform the 0w20 synthetic.

Oil base stock will not impact performance at normal temperatures. Only the life cycle/resistance to blow by and heat degradation over time. 5w30 will have higher film strength, hence the grade.

My UK Subaru manual mentions a 5W-30 but does not mention a conventional oil. So manuals are written differently based on regions and oil availability.

20 weight oil is resource conserving aka fuel efficient and hence helps produce less emissions. So manufacturers now use it even in hot desert climates of the middle East. I don't see why one needs to move to 5W-30 at all. Use a quality synthetic 0W-20 and do not overthink it mate.Attachment 210227

Sent from my SM-G781B using Tapatalk

Someone on the phone is tier 1 support. They could easily have misspoken.

You can read for yourself in the manual what is required (ILSAC GF-5 0w20). Keep your receipts. Do your oil analysis. Enjoy the peace of mind. Stop worrying and drive the thing.

Don’t let the EPA tell you how to protect your engine.
0W40 from day 1. Drive. Year round in Canada. Hard track about. 200,000kms with no engine issues.

You are a rare specie. I like you. :wub:

Look at the bearing oil clearances to get an idea of what oil viscosity to use. According to the service manual for Gen1, the FA20 oil clearances (no online access to Gen2 SM that I could find) should be between 0.00098" to 0.00217" which is a huge range honestly. Most bearing manufacturers have a suggested bearing clearance to oil chart. Here's one, the first result from Google.

According to the bearing clearances and this particular viscosity chart, a 5w20 is the recommended weight to use for most of the range of the bearing clearances, however 5w30 does fall within the looser end of the bearing clearances.

Not all oils are created equal though, particularly synthetics (which aren't even completely synthetic most of the time) and investigation into the particular oil's viscosity characteristics is probably suggested if you want to do a deep-dive.

Although once you deep-dive you see that there can be quite a large variance between the oil manufacturers and what is classified as what and then you begin to wonder what was the "standard" 5w20/5w30 oil that Toyota and Subaru referred to when they wrote their recommendation and what is the viscosity characteristics of that oil. Then you look at the charts and go also hmmm...

Coming from two FA20's, I always switched to 5w-30 full synthetic, but I also live in Phoenix where summers are 120 deg. I sent in an oil analysis and I remember metal particulates were cut in half after switching on my 2017 BRZ.

Im at 1,200 miles on this one, and I just switched to 5w-30 and a magnetic drain plug.

I also ordered some test kits, and I'll send in an oil analysis on my next oil change in the next 2k miles.

"0.025 — 0.055 mm (0.0010 — 0.0022 inches)" for connecting rods of a FA24, basically the same.

May i just have a oil change for dummy list of fluid i need ? i know it's a giant rabbit hole but is there a general consensus??

Besides oil weight , Brand and which type?

How about transmission and differential?

Not sure of general consensus for engine oil. Any big brand for full synthetic 5w-30 or 0w-20 will work honestly. Personally, I really like Motul as a company, but they are pricey in the states.


Now, for transmission/diffy fluid, there's an overwhelming consensus (maybe not consensus, but you can't go wrong with it) for Motuls gear 300 75w-90. Its just really good. Definitely removes some of the clumsy shift feel, especially between 1st and 2nd gear.

@Daedex Would you mind posting a link to the magnetic drain plug you got, please? It would be much appreciated!