Running different oil weights for summer season (AutoX/Track)
 

Looks like it’s pretty well understood 0W-20 (the recommended oil) gets thin at high temps based on its viscosity.

Spoke with a gen 1 owner who mentioned only in the summer when doing track and autocross days he switches to 5w30 in stead of 0w20. Anyone doing the same by chance? His cars at 100k+ of beating the hell out of it.


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Plenty of people update to 5w-30 or 0w-40 and sometimes more in hot weather seasons or especially track and autocross. There's also plenty of people that just sit at 0W-20 forever (mostly folks who don't see the track). It really depends on your use of the car. But 5W-30 isn't a huge step up from 0W-20 and is perfectly acceptable. It is even mentioned in the manual if you are so particular about that stuff.

My main use has currently been daily driving my BRZ, so I haven't bothered switching to a higher weight oil. I tried it one summer, noticed basically no difference in oil temps, and decided to go back to 0W-20 and have stuck there since.

Higher viscosity oil won't do anything to the oil temp, but it should keep the oil pressure higher in higher temps. Sadly there is no OEM oil pressure sensor (only a switch) so without adding an external sensor and gauge you can't really verify the benefit of higher viscosity oil.

My bad, you're correct, not sure why I had that confusion. In any case, the pressure difference at these two oil weights is so minimal in a DD that I just went back to stock spec'd oil weight.

I’ve always ran 0w20 + an oil cooler

I've owned my GR for a year now. It gets super hot here in the summer plus Autox. I'm thinking of switching out of the OEM weight. The Manual does say 5w-20 can be used.

Also, based on this video. This Engine loves to be hot. I noticed this last summer while driving under heavy loads. I felt the car get quicker. It happened again last weekend. Or I'm going completely insane and my brain thinks it's happening.

https://www.youtube.com/watch?v=uapDj34-wIs&t=606s

If you're tracking the car, IMO good high-HTHS (high-temp/high-shear) 5w30 is a must. I ran Redline 5w30 in the '17 and will run that in the new '23 for track season as well. They advertise HTHS of 3.7 mPa-s, where 5w30 is 3.0 minimum, and 0w20 can be as low as 2.6 (I think these #s are correct but going off top of head here...)

You don't have to "verify" anything with oil pressure readings, 0w20 have a known specified viscosity and HTHS range, any 5w30 will definitely have greater viscosity and greater film strength at higher operational temps.

Avg highs of 82/84 in July and August is "super hot?"

Don't ever move south of the Mason-Dixon line, you'll melt.

5W-20 is the way to go. A few folks on another GR forum I can't write on here otherwise it wont let me post had a thread, and one of the folks who was chiming in is a pretty credible source of information as he works in that industry.

The TLDR is that with 5w-20, engine happy and better protected at full temp and during spirited driving without sacrificing anything but a few MPG's during your first 15 mins or so while it's warming up and that running super thick oils just for the hell of it isn't a great idea.

Yeah, I autoX once a month during summer months. Not sure if I should switch over or keep my OEM weights? I'll figure it out... I don't drive the car much, only on weekends to get bagels or breakfast for the wife and kids- which I look forward to all week.

If it's just one a month, 0w-20 is fine. Just about everyone here running gen 2's runs 0w-20, including top-dog national level drivers. They push their cars hard.

I've run 0w-20 in my 2017 the last 3 seasons. This past Saturday, we did 12 (yes, 12) back to back runs at the Starting Line School on a ~35 second course. My oil temp gauge stayed around 235 and I'm surprised it didn't go much above that considering 12 runs with about ~1 minute in between each is a lot. At normal events, it rarely gets above about 220 by the end of a run and cools down to ~200 before the next.

I do recommend a "better" oil if you are autocrossing though. I run Motul, but Redline, etc... IE, an oil you're probably going to pay a bit more for, but might resist wear over the longer term better than OEM.

Track days are when you need to start looking at 5w-30's. From what I can tell through my testing, you won't get the oil hot enough during even repeated autocross runs to warrant any pressure benefits from the 5w-30.

5W20 isnt that far off your OEM weight, and it's already in the manual in gray area fine print that you can run that weight anyways lol. That being said, I'd be changing your oil after every event if you're doing some hard hard driving.

just be warned, 5w-30 is not listed as an allowable engine oil formulation in the owners manual, so if you're concerned about maintaining the factory warranty, don't run anything outside of 0w-20.

My FA20 spun a bearing on 5w-30 during an autox, 117k miles, the last 40k miles were on 5w-20, first 75k we’re on 0w-20, sticking with 0W-20 for the second build. ymmv