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

[zeroptzero]

With my 2024 Subaru BRZ it runs a 0w-20 oil from the factory and as the recommended oil. I have it in winter storage right now with only 200 kms on it. It will go on the road in May as a weekend only garage queen car. I have a daily driver that I use for work, and I just want a weekend toy to putz around during warm weather months (3 seasons). It will be driven easy, not pushed hard at all, and no track use, I won't likely drive it in the rain. I expect to do one oil change per year, which should be plenty for a low mile vehicle.

I bought a stash of Amsoil 5w20 recently as it was on sale at a store going out of business, I have enough to last me for the 2025 season. I wanted to do 5w20 for the lower NOACK numbers, it is a pretty decent difference compared to 0w-20. If I go to 0w-30 the NOACK numbers increase from 5w20.

I was considering 0w-30 to potentially lower engine wear but the operative word is "potentially". On a car that is driven lightly in optimal ambient conditions would there be much wear difference between 5w20 or 0w30 ? Obviously the engine isn't going to die off just from running a 20 weight oil , but would there be much wear difference between 0w-30 or 5w20 ? I could run 5w30 to get the NOACK numbers back down, so that is an option, but if the wear difference is small I might be okay with 5w20 this year. I do have a chance to buy more of the discounted oil which would cover me for 2026 if I bought it now while on sale, I just have to decide if I want to buy more of the 5w20 or wait to run a 30 weight.

Thanks for reading , and any opinions on this

 

[skyactiv]

If any car ever needed a thicker oil than 0W20, it's the BRZ and GR86. You should run Mobil1 ESP 0W30 in that car.

 

[Fa24wrx]

If any car ever needed a thicker oil than 0W20, it's the BRZ and GR86. You should run Mobil1 ESP 0W30 in that car.

Based on what? The oil starvation from lateral g?

 

[zeroptzero]

If any car ever needed a thicker oil than 0W20, it's the BRZ and GR86. You should run Mobil1 ESP 0W30 in that car.

I'm thinking it would be 100% needed in harsher driving conditions, and no question about track driving. I just ask because I am older and my driving will be pretty easy with it. I sowed my wild RPM oats with a Honda S2000 over a 9 year period, I won't be rev happy with this car nearly as much. Thanks for the recommendation I will certainly look at that.

 

[Fa24wrx]

I'm thinking it would be 100% needed in harsher driving conditions, and no question about track driving. I just ask because I am older and my driving will be pretty easy with it. I sowed my wild RPM oats with a Honda S2000 over a 9 year period, I won't be rev happy with this car nearly as much. Thanks for the recommendation I will certainly look at that.

0w20 will probably be fine, especially if you're worried about warranty.

 

[DemoFly]

I would be able to tell immediately

 

[zeroptzero]

0w20 will probably be fine, especially if you're worried about warranty.

I do have an extended warranty , but I'd like to go with 5w20 over 0w20 for the improved NOACK numbers on the Amsoil product

 

[zeroptzero]

I would be able to tell immediately

Tell what ?

 

[Fa24wrx]

I do have an extended warranty , but I'd like to go with 5w20 over 0w20 for the improved NOACK numbers on the Amsoil product

Id make sure you read the terms closely and stick with an API SP oil. Some extended warranties have a lot of stipulations

 

[zeroptzero]

Id make sure you read the terms closely and stick with an API SP oil. Some extended warranties have a lot of stipulations

good point, Amsoil has a lot of small print on their products, I do need to check that more closely.

 

[demarpaint]

If it were mine ESP 0W30 would be in it.

 

[Cujet]

To answer the OP's question, the difference is not noticeable. In fact, on cold days, the OW-20 will have higher operating viscosity than the 0W-30 on warm days.

 

[oilstained]

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

 

[Mewbs]

Depends on what type of driver you really are, most JDMs don't care much what oil you put in it as long it meets ILSAC. If you drive it hard and spirited, anything 0W-30 / 5W-30 or higher would do fine. If it was me, who would probably track the vehicle seasonally. I'd run 0W-40 or 5W-40 depending on your climate/region and call it a day. Japanese owners manual or anywhere else that is non-US will spec a wide range of oil viscosity grades since they are not constrained by CAFE regulations.

 

[Glenda W.]

For your driving conditions any 20 grade will be fine especially a high quality lube like Amsoil. But any long time or multiple Subaru owner will tell you these engines are happier on 30 grade and up oils. Less oil consumption, less noise, smoother etc. I own two Subarus currently and maintain 7 total for friends and family. Mobil 1 ESP 0w30 has proven to be the best Wally oil IMO. Amsoil or HPL if cost is not an issue.

 

[Jetronic]

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

I have a 0W30 with a KV100 of 12.2 cSt and 3.5 cP HTHS. 30% more viscosity is significant....

 

[zeroptzero]

Thank you for all of the replies on this. Yeah my light driving conditions made me wonder if 5w20 would be almost as good as a 0w30. The car will only be lightly driven, and my track days are behind me. Our climate can get pretty hot for about 2 months of the season, spring and fall months can be on the cooler side. I might start it up a couple times in winter months if I am moving it around, temps could be quite cold but it would not happen much. I do have my oil supply for the first oil change interval, but my post is mostly about what to use for the 2nd OCI . Thanks for all of the replies, lots of good information on this forum.

 

[TiGeo]

It's fine.

 

[kschachn]

And another thick vs. thin thread, this one with a side of Amsoil and a dash of "warranty concerns".

 

[Propflux01]

He has legitimate questions. Things change over time, so the age old thick vs thin doesn’t always apply. If it did, there would be no reason for this forum.