These things are debated ad infinitum on BITOG and for the most part, I'd say the consensus is that bumping up one grade does no harm. On the extreme end some people recommend 0w-40 for everything.

There are some cars that have fancy electronic oil pumps for which the viscosity might be more calibrated but even then, people who use higher viscosity don't report any issues. Notably viscosity is strongly a function of oil temperature, so being fixated on the SAE viscosity "number" can be extremely misleading. For example, the difference in actual viscosity between 0w-12, 0w-16, 0w-20, OVERLAP to a huge extent. A cSt at 212F of 7.0 will be within all three viscosity "grades" 12, 16, and 20!

 

That supports my feeling that 0W-16 vs 0W-20 is splitting hairs.

If protection/reliability is not a concern between the two I'd like to continue with my frequent cheap oil changes.

I see how the minute differences could impact Subaru with regards to the EPA and their whole fleet, but not anything meaningful for the individual engine.

 

Subaru has 1 EV in their whole lineup of vehicles, and they will be dropping the PHEV Crosstrek for 2024. If they can squeeze out a little extra performance and 1 MPG improvement with 0w-16 vs 0w-20 they will. Subaru in Japan uses 0w-30. I wonder if they will go to a lower weight oil too or if it's just for the US since the new EV factory won't be completed until 2027. I don't think 0w-20 or 0w-16 will make much of a difference. Subaru using Extra MT at the factory vs 75w-90 for the differential fluid since it gets a little bit extra MPG.

 

Not gonna do it. If I end up with a 2023 or newer car that calls for 0w16 it's getting 0w20. It nearly kills my anxiety to even use that, no way I'm going lower, don't care what the manual says. My 2022 XT gets Subaru's 0w20 right now but it gets changed every 5k, not 6k. I'm not convinced switching to 0w30 or 5w30 would kill it, especially because the book says it's ok to use in an "emergency". But I simply do not feel that heat and pressure on 16w oil is a recipe for long legs and high miles.

 

The thinnest oil I ever use is 10W30 (typically I use 10W40) and I will not use any thinner oil

I am in Australia but the recommendation here is mostly 5W30 or 0W20.

Seagrass

 

I'm in Hawaii and my Outback XT gets 5w-30 even in the dead of winter when it gets down to 60F.

 

My 20+ year old Honda holds 2.5 quarts of 0w20.

It calls for 10000 mile oil changes and 20000 mile filter changes.

At 200k miles on it it uses no oil between changes.

Lower weight oil doesn't scare me if the manufacturer recommends it.

 

My 20+ year old Honda holds 2.5 quarts of 0w20.

It calls for 10000 mile oil changes and 20000 mile filter changes.

At 200k miles on it it uses no oil between changes.

Lower weight oil doesn't scare me if the manufacturer recommends it.

Agreed. I previously owned a 2005 STi and completed oil changes every 10,000 miles. Zero issues. Each oil sample I sent to Blackstone came back with zero issues. In fact, I could have gone even longer based on the lab analysis. No reason to be scared. That's just silly.

 

You're talking about the 67 horsepower 1 liter 3 cylinder in the Honda Insight right?

 

That's the one!

 

It would be interesting to know what the dealers actually use during oil changes. My previous suzuki was specc'ed to use 0W-16 but each of the 3 dealers that serviced it always used 0W-20 "cos it makes no difference and is half the price".

 

I looked to see if Subaru had 0w-16 oil listed on their parts website and they don't. Idemitsu does make a 0w-16 though.

 

Walmarts in the US have Mobil 0W-16 at the same price as 0W-20. Don't know about Canada. My recent Toyotas call for 0W-16 and they all have held up well. One is going on 200k miles.

 

I realize that I'm probably paranoid after my terrible experience with a garbage GM engine, but the OBW wasn't cheap and I intend to keep it as long as possible.
With the added stress of the turbo and some occasional small boat towing I won't be taking the risk of slightly too old oil contributing to premature (or mature) wear. While towing in the summer I've seen the oil temperature reach ~10°C warmer than its standard ~100°C operating temperature. I'm now wondering whether it might be better to use 0W-30 in the summer for some added heat protection.

I'm less worried about stress on the 2.5L in the Crosstrek, but it'll be my wife's vehicle and she drives like how I did when I was a teenager. I've lost track of how many times I've asked her to give the engine a few seconds to get pressures up and fluids flowing before driving off, and to then drive gently for a few minutes before stomping on the throttle. If 0W-16 does in fact have faster warm up it might be the better option on her vehicle. 😆

Having to be on the lookout for sales is not something I enjoy which is why I love the Costco oil; it may be a couple of dollars more than the best sales, but it's always that price and it's always well stocked. I think that I'm going to go with 0W-20 in both vehicles for now. It will be wonderful to have both with Fumoto valves using the same oil and the same filters.

 

Fair enough. Do whatever makes you feel best.

Be aware that Subaru recommends using premium fuel (91+ Octane) when towing with the 2.4T.

If you're going for maximum longevity it is something to be aware of since you specifically mention towing.

 

Personally, I would NOT hesitate to use 0W 20 even 5W 30 (while recognizing a diff engine than my OB and I actually use 5W 30 for warm months). A few things:
1) the Japanese manual of 2023 Crosstrek calls for 0W-20 to 5W-30 (CROSSTREK　取扱説明書ダウンロード｜取扱説明書ダウンロード｜アフターサービス｜SUBARU) - couldn't find a JP version of 2024
2) consequently, (in general) engines are designed to "easily" handle one grade up or down (or thinner or thicker grade of oil) - from friends who works for tranny oil / engine oil companies (with Ph D in material science, etc.) - and I am assuming you are not going racing with your crosstrek
3) as you indicated, lower viscosity is primarily driven by the MPG / environment requirements - and NA is by far the biggest market for Subaru

As SilverOnyx suggested, you should also check BITOG as well.

 

Either way you'll be fine. The higher viscosity won't do any harm and the thinner one the engine is designed for will function perfectly fine. It's not like it's turbocharged. In my case with the xt I do these almost exclusive short trips which are awful for oil especially on a GDI engine.

0w-16 and 0w-20 synthetic are said to use better base oils than common 5w-30 to resist breakdown so it's not simply "thin oil" it may be better engineered oil to compensate.

On one hand my oil rarely gets very hot so my oil is already thicker just from being on the cool side (below 200F). On the other hand my short trips with direct injection put gas in the oil enough that my worry is viscosity thinning from dilution. Hot oil vaporizes gas and moisture purging it from the oil over time and short trips don't have the time and temperature.

I was using Rotella T6 5w-40 on my 2011 WRX and in my mind dropping to 0w-20 for a turbo was just a mental thing for me. With the 2022 WRX on Bitog there's the same old argument about thick vs thin oil. 11 pages https://bobistheoilguy.com/forums/threads/2022-wrx.358283/

My position about thick vs thin is based on real world used oil analysis for a particular engine and how much viscosity loss is demonstrated in the first 3000 miles, and the temperatures that your oil sees.

Is there any oil viscosity difference between the Crosstrek's 2.0 and 2.5 engines?

 

Is there any oil viscosity difference between the Crosstrek's 2.0 and 2.5 engines?

Both call for 0W-16.

 

My past experience has led me to take the position that manufacture recommended oil change intervals should be considered a maximum limit rather than a safe target.

Based on what? I generally consider it a minimum unless a UOA tells me otherwise. I've had to stick with 7500 on my Mazda3 (fuel dilution...thanks, DI) but safely doubled my previous Altima to 10k with zero ill effects.

 

I was changing oil on our 2013 Equinox every 7000-8000km when the recommendation was 7500-10,000 miles. The piston rings became gummed up with sludge and it began burning lots of oil after fewer than 5 years and 100k kilometers.

A day of doing a few oil changes and a few hours of highway driving cleared enough sludge to salvage it. For the past 100k kilometers it's been able to go 3500km after an oil change before it becomes too fuel diluted and degraded and begins to burn off again.

A family member has the same vehicle and did changes every 5000km - no issues with their engine.

GM had a known issue with their piston rings, but they also say that if it burns 1 liter every 3200km that's "fine". The carbon deposits on the intake valves tells me otherwise. Yes I know DI engines pretty well all suffer from this issue to some extent, but you wouldn't believe the slurry that empties into the intake plenum and down onto the throttle body

I know there are lots of people that follow the recommended intervals without issue. I'm fully aware that I'm doing overkill with 5k km instead of the recommended 9k-10k km but I meet some of the criteria for severe service and want to err on the side of extra caution. At every 5000km it costs me less than $200 a year for oil and filters.

Another point of evidence that makes me distrustful of recommended maintenance intervals is that SOA says the CVT fluid is lifetime unless towing. Subaru Canada recommends every 5yr/100k km unless towing. In this instance "lifetime" sounds more like "warranty period".

 

If you do UOA to establish your oil change intervals that's fine but if you don't do UOA's then it makes sense just to err on the side of caution, and to pay attention to the severe service schedule and whether or not your car falls under it. Unfortunately it's all in the fine print and few people look at that.

So if you're not doing UOA's it's reasonable to consider the regular intervals as best case scenario (mainly long highway drives) and severe service as the worst case scenario, so choosing something in-between is reasonable. And we are talking about direct injected engines in the Crosstrek.

 

I've got a 2024 Crosstrek 2.5L on order and have just seen in the manual that Subaru is now calling for 0W-16 oil.

My understanding is that the 2.5L has been slightly revised and now produces a whopping 2 whole extra ft•lb of torque. Do you think there have been changes that necessitate 0W-16? The manual says that 0W-20 can be used to top off if replenishment is needed, but should be changed back to 0W-16 at next oil change.

I know 0W-16 is thinner than the called for 0W-20 in our Outbacks and so should provided better cold weather warm up and fuel efficiency, but at the cost of high temperature protection and, well, cost.

My past experience has led me to take the position that manufacture recommended oil change intervals should be considered a maximum limit rather than a safe target.

I think the notion that clean oil (that meets the latest specifications) is going to perform and protect better than dirty oil, even if that dirty oil is an advanced formula that can outlast other brands.
In my OBW I am changing the oil (and filter) every 5000km using Costco's Kirkland brand oil.
My thinking is that the interval is overkill, but the oil is cheap (and at a consistent price) and still meets the latest specifications. It'll never be at risk of degrading too much and being so clean might reduce carbon deposits/sludge.

While I'm not specifically against using 0W-16 in the Crosstrek, my Costco here in Canada doesn't carry 0W-16. In fact there is very little 0W-16 available at local auto parts stores and they're easily x2 the price.

Given that the engine probably hasn't changed all that much, and the requirement to use 0W-16 is most likely related to their published fuel economy, do you think it's fine to stick with 0W-20? Yes, I know that warranty denial is a possibility since it's not what the manual says.

I know there are lots of knowledgeable people in here, I'd love you hear your thoughts.

0W-16 has been around for cars a couple of years now used mostly for Toyota's .. Toyota is a part owner of Subaru BTW.

 

I've got a 2024 Crosstrek 2.5L on order and have just seen in the manual that Subaru is now calling for 0W-16 oil.

My understanding is that the 2.5L has been slightly revised and now produces a whopping 2 whole extra ft•lb of torque. Do you think there have been changes that necessitate 0W-16? The manual says that 0W-20 can be used to top off if replenishment is needed, but should be changed back to 0W-16 at next oil change.

I know 0W-16 is thinner than the called for 0W-20 in our Outbacks and so should provided better cold weather warm up and fuel efficiency, but at the cost of high temperature protection and, well, cost.

My past experience has led me to take the position that manufacture recommended oil change intervals should be considered a maximum limit rather than a safe target.

I think the notion that clean oil (that meets the latest specifications) is going to perform and protect better than dirty oil, even if that dirty oil is an advanced formula that can outlast other brands.
In my OBW I am changing the oil (and filter) every 5000km using Costco's Kirkland brand oil.
My thinking is that the interval is overkill, but the oil is cheap (and at a consistent price) and still meets the latest specifications. It'll never be at risk of degrading too much and being so clean might reduce carbon deposits/sludge.

While I'm not specifically against using 0W-16 in the Crosstrek, my Costco here in Canada doesn't carry 0W-16. In fact there is very little 0W-16 available at local auto parts stores and they're easily x2 the price.

Given that the engine probably hasn't changed all that much, and the requirement to use 0W-16 is most likely related to their published fuel economy, do you think it's fine to stick with 0W-20? Yes, I know that warranty denial is a possibility since it's not what the manual says.

I know there are lots of knowledgeable people in here, I'd love you hear your thoughts.

0W anything is just for the manufacturers EPA mileage rating. Not good for your car. If you are in the southern US then 0W-16 makes no sense if you care about engine longevity. 5W-30 is the best compromise. I’ve used it for the last 12 years and nearly 190K miles. Engine wear is minimal based on oil analysis.

 

Probably to help prevent carbon build up on the valves with direct injection, the newer 0w16 oils are formulated to help prevent it. That thinner blend apparently has been used in Japan for several years. and now making it's way to the US under the new ILSAC GF-6(B) spec.

 

I operated an import car repair shop in my working life, and Mobil introduced their Mobil1 synthetic oil around the early to mid 1970s. At that time, Mobil recommended that if you changed over to their oil, you could safely go 1 full year or 25000 miles, whichever came first. I sold lots of it to many different folks, and the only modification I made to the recommendation was to change the oil filter at the normal interval and top up the oil with however much was required. I operated my own vehicles the exact same way. I drove a BMW 6-series, a Toyota Supra, 2 Toyota Cressidas, a Datsun 280Z, many different VW and Audi cars, among others. I never had any sort of lubrication-related failure in any of my or my customer’s cars during 20 plus years of following that maintenance process.
Therefore, I strongly feel that today’s relatively frequent intervals of changing synthetic oils are patently ridiculous. However, I do understand that one must follow manufacturer recommendations or risk voiding the warranty.
My recommendations always and only applied to vehicles that were out of warranty. In those days, warranty periods were significantly shorter in duration.
So, this nitpicking over 0W16 versus 0W20 is more likely due to Subaru wanting to sell overpriced oil that can’t be easily found on the aftermarket. Jus’ sayin’!

 

When Mobil1 first came out it was a true synthetic but then Castrol Syntec came out, called itself synthetic, but was a hydrocracked petroleum not considered a true synthetic. They were sued but Castrol won, and in response almost all commodity synthetic oils are now hydrocracked group III including Mobil1.

So that sets the stage why most of today's synthetic oils you find at Walmart aren't what the original Synthetics were at introduction.

Then because of fuel economy and pollution concerns, certain wear reduction additives were reduced (zinc which poisons catalytic converters), engines came with low tension piston rings, and now we have direct injection that creates soot in the oil, that port injection didn't do. The soot is abrasive so it's causing timing chain wear which makes it loose and you get elongation. Pair that with more dilution of the oil with fuel during cold operation where the fuel sprayed directly into the cylinder washes down the cylinder walls instead of perfectly vaporizing.

So there are many reasons why today's oil change intervals end up being shorter than long ago. The oils are in some ways worse, the engines are more susceptible to sticky piston rings, and the oils are more heavily contaminated.

Edit: Research has shown that thicker oils protect better against the abrasive action of soot in the motor oil, so if you're a short trip driver with heavy fuel dilution and soot in your oil, that's why severe service has extra short intervals of 3 months and only 3000 miles - thin contaminated oil doesn't last long.

 

Nicely done Onyx! I used my dealer for my first oil and filter change at 3000mi. My direct injected strong little turbo boxer shall have frequent oil changes and I will sleep well at night

 

Well, you’ve got me there! I’m just a mechanic. I have never heard the term “hydrocracked” before, and I have no idea what it is. I do know that BMW-branded oil is labeled “full synthetic “, and it was supplied to BMW by Castrol. We dealership mechanics were told that it was Syntec, and that was good enough for us at the time.
What you have just stated is quite distressing to me. If all that is true, then the oil companies have been screwing us in more ways than just at the pump.
I’m glad that I am retired and out of that crappy business.

 

How about Amzoil signature series? Still actual full synthetic?

 

Yes, but the Signature Series doesn't meet API or ILSAC specs if that matters to you. But one should just choose an oil based on specs that an oil meets rather than being focused whether or not any particular brand is "full synthetic" IMO.

Generally speaking, a 0W-x has to be made from better base stocks than a 5W-x in order to meet the cold cranking requirements anyway.

 

Yes Amzoil signature, Redline, Motul, are "real synthetics" but because I do short trips in my turbo, I'm doing an oil change every 6 months with only 2k miles on the oil. I'm using cheap fake synthetic and just changing it often. Even the world's best synthetic doesn't get rid of soot - you have to change the oil to do that. Direct injection is a real double edged sword.

 

My other new "car" is a '22 F150 PowerBoost . It's 3.5LTT has direct and port injection so the back side of the intake valves get a good bathing in premium fuel. I like that design feature. It will still get some fuel contamination in the oil, but I wish my Touring XT had it. Both my vehicles put a smile on my face every time my right foot gets heavy!

 

Shouldn't this thread be in the Oil, Oil Filters, and Fuel Discussion forum? Asking for a friend.