0W20 vs. 5W30 Test Data

[Lonewolf]

@PST I always look forward to your posts...so much detailed info and data...love it

[D_Thissen]

Would a 5W30 oil be safe to use in the winter?

[JB86'd]

So for a DD in Socal that sees mostly weather above 50° F, some spirited driving and occasional autox is it a toss up? Or still go with 0w-20?

Thanks for doing this test and sharing your data

[bluesubie]

These cars are brutal on oil when it comes to the track. IIRC, Mike at AZP Installs did a used oil analysis on Motul 300V 5W30 and the oil sheared to a 20 weight which is no easy task because 300V is a very shear stable oil. It also is a very thick 30 weight with a high High Temp High Shear so it's very close to a 40 weight when new.

You can also fine tune your oil pressure by doing a mix of 5W40 and 5W30 if you don't want to go with full 5W40.

Subaru Japan allows 5W40 in the BRZ in harsh street driving conditions so that's saying something, IMO.

[GSpeed]

Originally Posted by D_Thissen

Would a 5W30 oil be safe to use in the winter?

I've spent the majority of my adult life in states that border Mexico, so I have no personal experience with winter weights. I suspect it would be okay based on the research Element Tuning has done, but I'd defer to someone more familiar with that region. I believe they found the engine is not that sensitive to heavy weights when cold.

Originally Posted by JB86'd

So for a DD in Socal that sees mostly weather above 50° F, some spirited driving and occasional autox is it a toss up? Or still go with 0w-20?

Thanks for doing this test and sharing your data

You're very welcome. I'd say it's probably a toss-up. So long as you're staying with the same oil (synthetic, non, ester base, etc.) you shouldn't have any issue changing weights for different events.

Originally Posted by bluesubie

These cars are brutal on oil when it comes to the track. IIRC, Mike at AZP Installs did a used oil analysis on Motul 300V 5W30 and the oil sheared to a 20 weight which is no easy task because 300V is a very shear stable oil. It also is a very thick 30 weight with a high High Temp High Shear so it's very close to a 40 weight when new.

You can also fine tune your oil pressure by doing a mix of 5W40 and 5W30 if you don't want to go with full 5W40.

Subaru Japan allows 5W40 in the BRZ in harsh street driving conditions so that's saying something, IMO.

Absolutely. We change oil every ten hours of run time since our car is a pure track rat.

Jake

[hpde_addict]

Originally Posted by JB86'd

So for a DD in Socal that sees mostly weather above 50° F, some spirited driving and occasional autox is it a toss up? Or still go with 0w-20?

Thanks for doing this test and sharing your data

You will want 5W30 for spirited driving and autocross. It's hot as hell in SoCal during the summer.

[Jack Black]

Why don't you have any temp data below 210* for 5w30 but you do for 0w20?

[Dezoris]

If you are in a hot climate, you might as well just run a 10w30 over 5w30 for stock cars. Most oils have to make trades offs to have a lower winter weight. This is usually not apparent until you get the oils in the higher end of their temp ranges.

[RedBRZ80]

I've been running 5W30 Motul for the last 50k miles.. In Florida.. With twice a month autoX and a few track days to boot.. Just about perfect.

[CSG David]

We use 0W20, 5W30, 5W40, and rare occasions of 15W50. Different grades for different applications.

[GSpeed]

Originally Posted by Jack Black

Why don't you have any temp data below 210* for 5w30 but you do for 0w20?

The test file I used for 5W30 started with oil temps at 210. I'd already warmed the car up, filled it up with gas, etc. I'll have to go back through some other log files to see how it looked during the "warmup" period, but I don't remember it being any higher than the 0W20 from what I remember on the display. I won't be in the office until Wednesday (this is my weekend) so I'm working off of memory here, sorry.

Originally Posted by CSG David

We use 0W20, 5W30, 5W40, and rare occasions of 15W50. Different grades for different applications.

Interesting! Would you mind sharing some of the temp vs. pressure data for the 5W40 and 15W50?

Jake

[Calum]

Originally Posted by CSG David

We use 0W20, 5W30, 5W40, and rare occasions of 15W50. Different grades for different applications.

I'm running 5w30 up here in Nova Scotia in a DD. For reference, it was 16 degrees C today on my way to work and my oil temp was over 100 degrees C just driving in light traffic at ~110-115 kph.

I really need to install a pressure gauge but I'm still waiting to see if someone will develop a sensor that will inject a signal on the bus so that it could be monitored with torque. High hopes, but I really hate the look of aftermarket gauges in my car.

[CSG David]

Originally Posted by PST

Interesting! Would you mind sharing some of the temp vs. pressure data for the 5W40 and 15W50?

Jake

We don't have the logged data for 5W40 and 15W50. What we do know is the oil pressure isn't completely optimal even at 5W40 and 15W50.

[#maverick#]

Originally Posted by CSG David

We don't have the logged data for 5W40 and 15W50. What we do know is the oil pressure isn't completely optimal even at 5W40 and 15W50.

So I would be able to run 15w50 without issue, during the hot summers here on a boosted frs?