In Light Driving Conditions Would You Notice Difference in 5w-20 vs 0w-30 - Subaru BRZ

[Hohn]

So you're saying that an engine with low tension oil rings consume more oil if I use a higher grade? How high?

My Tiguan has low tension oil rings I believe, but it consumes less of a Euro 30-grade than it does a 20-grade. I just don't see it.

Not saying it *will*. Saying it *can*. And if it did, it's almost certainly so minor nobody would care. Like, it's the difference between your cats being plugged or poisoned at 200k instead of 250k miles.

That level of thing.

The only reason I mention it is because a lightly driven car seeing only seasonal use is one of the few cases where it could potentially matter that a thicker oil might be slightly too thick. It won't be giving the pistons the temperature and pressure they need to seal optimally and scrape oil efficiently.

Again, quibbling little theoretical concerns that in the real world amount to basically nothing. But this is BITOG, where we specialize in making little insignificances into big points of concern, so I thought I'd mention it.

 

[Hohn]

That’s extremely rare despite many thinking it’s more common. Often “real world” results are so clogged with bias and assumptions that once they are properly analyzed do not yield the conclusion first assumed.

People draw conclusions based on bias and assumption on many things. The term is “illusory correlation”.

Facts should always correlate to any observation.

100%.

There's a lot of improper conclusions that follow in sentences that begin with "the data says." No, it doesn't. The data is just data. All its meaning it in the eye of the observer. There's a million ways that data gets corrupted, tests are improperly executed, the wrong things are measured, the wrong measurement tools are used, etc etc.

While it is (or used to be) someone commonly expressed that "correlation isn't causation" or--more formally-- that correlation doesn't necessarily imply causation, this wisdom is fading and people indulge that fallacy.

But I also see the other side of this: I commonly encounter that people forget that lack of correlation completely shows lack of causation.

A great example of improper interpretation of correlation is found in Milton Friedman's thermostat.

 

[Propflux01]

That’s extremely rare despite many thinking it’s more common. Often “real world” results are so clogged with bias and assumptions that once they are properly analyzed do not yield the conclusion first assumed.

People draw conclusions based on bias and assumption on many things. The term is “illusory correlation”.

Facts should always correlate to any observation.

Tell that to the manufacturers of vehicles with engine and transmission issues that caused recalls and major maintenance issues, who had “all the facts and data” when manufacturing, that didn’t quite jive in the real world.

Again, I don’t assume anything.

 

[Revving2Redline]

Subaru Japan used to recommend 0w30 and 5w40 for the first gen BRZ and they still recommend 0w30 for current gen models. http://www.pleiades-zero.com/?page_id=342
View attachment 267895
"Perfect for BRZ"

Toyota Australia also mentions 5w30 as a recommended viscosity in the owner's manual for the GR86.
View attachment 267896

Subaru and Toyota are both fine with higher viscosity oils in these cars. Personally, I switched to euro 30 or 40 weight oils in my FRS a year after I bought the car.

That five gallons bucket is beautiful, I dislike Subaru, buy I would buy the five gallon. Great post, thanks!

 

[barkingspider]

I say use that amsoil 5w20 you got in your stash

 

[zeroptzero]

I say use that amsoil 5w20 you got in your stash

Yes absolutely, that will be my first oil change once I dump the break-in oil. The replacement for my 2nd oil change and long term use will be the decision to make.

Thanks

 

[zeroptzero]

If I move away from Amsoil 5w20 on future changes , I might stick with Amsoil and go with 0w30 . I only have one oil change a year given the mileage I drive. Some of the OTC oils that have gone to Euro or emissions protecting formulas seem to be down on additives. I understand the reasons but I'm still old school and I like to see higher levels of additives.

 

[Fitter30]

Engine tolerance is so tight if that what the manufacturer want that's what it should get.

 

[Glenda W.]

Engine tolerance is so tight if that what the manufacturer want that's what it should get.

Wut?

 

[kschachn]

Wut?

Spurious Reason #235 “Why Some Engines MUST Use Thin Oils”.

 

[Revving2Redline]

Engine tolerance is so tight if that what the manufacturer want that's what it should get.

I believe at one time or not too long ago some of the Corvettes were filled with 5W-30 synthetic but in the owner's manual it recommended to fill it over by one additional qt and that 15w50 was recommended for extremely aggressive driving and or on the racetrack. I've said it before and this isn't to be argumentative, there is a lot of people who drive their cars like they stole them and then we have a few car enthusiasts on here that leaving a car stock just isn't for them and will add anywhere between simple bolt-ons to full size aftermarket turbos where the power increase can be anywhere from a mere 20 horsepower increase all the way up to double the factory power of the car. Surely there is some room for alternative weights. For far too long Hyundai and Kia gave alternative oil choices in the manual going back as far as my 2012 Hyundai Accent from a 5W-20 to a 10w30

 

[Speedy3861]

Based on common sense, recommendations from more knowledgeable members on the forum like @kschachn and advice from my Honda Certified Master Technician at my dealership, I switched from Mobil1 0w20 EP to Mobil1 5W-30 EP to cope with the Honda 1.5T's ongoing oil dilution issues rather than the constant UOA's, i just do OCI's between 3-4k and stopping worrying about it. No real difference in mpg, apparently less dilution (oil not rising on the dipstick) and no real discernable difference in cold starts. Oil is changed at the dealer using their Honda 15400-PLM-A02 filter, no warranty issues. Honda is more concerned with regular oil changes with an oil with proper approvals than viscosity when it comes to warranty.

 

[zeroptzero]

Based on common sense, recommendations from more knowledgeable members on the forum like @kschachn and advice from my Honda Certified Master Technician at my dealership, I switched from Mobil1 0w20 EP to Mobil1 5W-30 EP to cope with the Honda 1.5T's ongoing oil dilution issues rather than the constant UOA's, i just do OCI's between 3-4k and stopping worrying about it. No real difference in mpg, apparently less dilution (oil not rising on the dipstick) and no real discernable difference in cold starts. Oil is changed at the dealer using their Honda 15400-PLM-A02 filter, no warranty issues. Honda is more concerned with regular oil changes with an oil with proper approvals than viscosity when it comes to warranty.

I had one of those Civics in 2016, my engine was producing oil , lol, about halfway through the OCI I would need to drain the oil as it was overfilling so much due to moisture and fuel. This was before the apparent "fix" Honda came up with, they did the recall fix on my car but it didn't help much. I would never run a 20 weight oil on that turbo direct injection motor, I sold the car as I was worried it would blow up out of warranty . I am quite surprised many of those engines are still running strong and we didn't see many failures back in the day. I don't follow that car or motor much since selling it, but it was horrible being the laboratory rat for Honda on that first production car with that motor.

 

[zeroptzero]

I found some additional Amsoil 5w20 on sale this weekend at an outlet of a hardware store that is going out of business. I could not resist the opportunity to get it at a discount. I now have 14 quarts of this oil in total, that is enough for two oil changes, and a couple spare quarts for top-up.

 

[SubieRubyRoo]

The difference between 0W-20 and 0W-30 is so small, it’s insignificantly unsubstantiated.

That’s not true (assuming virgin oils at the same temp); if the difference was as small as you imply, the oils would be classified as the same grade. And it’s easy to substantiate; there’s literally a thing called a viscosity test. It’s ASTM D445 & you can learn about it here: Oil Test List

If you had a qualifier that said, “0w30 may be as thin as 0w20 if it is at a higher temperature, but at the same cold temps, the 30 grade will always be thicker,” you’d be mostly covered. Besides, in the OPs case he would be better served by the HT/HS test results rather than solely viscosity if he’s interested in preventing wear, and unless he’s starting the car in temps colder than -30F the 5wXX oil is just fine. Here’s SAE J300 Infofor you to review.

 

[CharBaby]

Engine tolerance is so tight if that what the manufacturer want that's what it should get.

Do you mean "engine clearances"?
If "clearances" get any tighter, the engine wouldn't be able to rotate.

 

[Triple_Se7en]

In Light Driving Conditions Would You Notice Difference in 5w-20 vs 0w-30​

If your definition of Notice includes Hearing, yes, you may get a change.
Even during your driveway warmup idle.

 

[Triple_Se7en]

Yes absolutely, that will be my first oil change once I dump the break-in oil. The replacement for my 2nd oil change and long term use will be the decision to make.

Manufacturers do not institute break-in motor oils at the factory. Modern-day / digitally mastered robotIcs (AI) to the rescue.
Use that factory-fill for 3k minimum.

 

[zeroptzero]

My other two vehicles use 0w-20 motor oil (VW and Ford Escape). I definitely notice that the cold start up sound is very different compared to past vehicles that used 30 weight oils (in cold winter months). There certainly is a time and place for 20 weights in our region .

 

[bubbanik]

I agree, thank you.

Absolutely right!
Never ceases to amaze me how upset some folks get over someone "repeating" a question that has been asked. Like there is some irresistible force requiring you to add input.
Here's a novel concept...ignore it.
Reminds me of my daughter and Facebook.