0W20 vs. 5W30 Test Data

[CSG Mike]

Originally Posted by #maverick#

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

I wouldn't recommend it unless you have a very specific need; we did it for experimentation purposes.

[Element Tuning]

Just remember you should run what you need for how you run your engine. Street guys and NA guys just don't have the need for the higher oil pressures and they don't see the elevated oil temps. As a rule of thumb you have more oil pressure, as the OP shows, with cooler than hotter oil temps.

Know what your oil pressure needs are, get an oil pressure gauge, monitor pressure, and adjust viscosity as needed to get the oil pressure you need. Oil brands matter but you will find that Amsoil, Red Line, and Motul often stay in grade better than chain store oil brands as the temps rise. Nerd data is out there comparing viscosity at very high temps and some are just way better than others.

[sosick]

Originally Posted by rice_classic

http://lmgtfy.com/?q=Motul+300v

Lol

[nikitopo]

I think that even a 5w30 oil is not suitable for short races. Bride team is using in the Gazoo 86/brz races (a race of just 10 rounds) a 5w40 oil.

The decision of the factory to use a 0w20 oil was just for consumption purposes. It is a pretty much a useless oil for racing or spirited driving.

[pepe]

Could you tell me which are temperature and oil pressure adequate job in this car? thank you

[steve99]

Originally Posted by pepe

Could you tell me whiceh are temperature and oil pressure adequate job in this car? thank you

In the Bolt on mods link below is a link to an oil pressure vs temp video which explains things quite well.

[glamcem]

Originally Posted by PST

and pressures were dropping below 5 psi in the pits at the end of the session. Oil temps as reported by the ECU were well over 270°.

that's insane considering the fact the oil temps drop remarkably soon after the cool down laps especially with the stock levels ...also looking at the chart, it's easier to see how bad is the Motul V300 0w-20 when it comes to oil pressures, even during the oil's normal operating range for track use (220-260)

last year, I have been trying to explain why the 0w-20 would be a bad idea for track use (even for a stock car) but most people argued and tried to explain how good is the ester based oils I was running Mobil 1 0w-40 at that time, also tried Motul V300 5w-30 and Mobil 1 5w-30 after that.. between the Motul V300 and the Mobil 1 5w-30 (same ambient temps and power) I didn't see a big difference in terms of the oil temps and the recovery time and since the Mobil 1 5w-30 is drastically cheaper than the Motul, changing the cheaper Mobil oil more often made more sense.. if you think about it if you ever see the oil temps above 280F that oil should be changed immediately, regardless of the tag price

In my experience Mobil 1 5w-30, keeping the oil temps below 270-280 range and changing the oil more often seems to be working better than running 0w-40 grade oil, since both my friends and I had the similar experience after switching back to the 5w-30 .. thicker oil doesn't always mean a better protection or more stable oil temps (and ultimately more stable pressures) .. the key is the "ideal grade" for the application,

I've replied the below on a similar topic :

why do we want to see more oil pressure ? because it's a good indicator of how stable is the oil flow (fluidity) in the engine , well in theory yes but thinner oils do that naturally.. they're thinner so they flow better, get into the veins of the engine which ultimately balance the temps since it is the primary reason for the low temps ... so thicker doesn't necessarily mean more protective, well to some point yes .. if you think about it what would be the best oil if you keep your oil temps below 280 F, obviously the thinnest oil that you can get away with it..I've also heard many stories with people using 40 - 50 grade oil, racing teams use 15w-50 or 5w-50 oils but for race engines and special race oils AFAIK..

both me and my friends experienced the same thing when we switched back to 5w-30; the added friction was also responsible for the higher oil temps at track days... my friend's Miata is also boosted (KW kit) and he has full bolt on Camaro, similar results on all three cars .. it certainly has to do something with the tighter tolerances of the newer engines ..

[glamcem]

Originally Posted by kster1

Thanks for posting this. Since my car is naturally aspirated with an oil cooler, the highest oil temps I've seen at the track is 225F. Even at these "safe" temps, I'll keep running a mixture of 5w30/5w40 of Motul.

Originally Posted by Uncle Benz

I moved to 5w30 Motul 300v and the HKS oil cooler. At a recent trackday at Bedford Autodrome on the GT circuit I saw a maximum oil temp of 107 degrees Celsius, and 18 psi at tickover when returning to paddock. I never pushed the car hard before the modifications because tales of sky-high oil temperatures and <10psi in the paddock scared me a bit. I'm now seeing oil pressures of 125psi when the engine is cold, and this worries me a little too, so I've taken to letting the engine warm a bit before moving off. I guess you can't have it both ends??

Do you guys recall your average RPMs during the session? driving style is the most important contributor when it comes to the oil temps.. don't get me wrong but if you guys never really pass 230F mark (even with an oil cooler) on a hot day, you probably don't push the car as much..

[ls1ac]

Just to add two more pennies to the pile, the first number is the base weight of the oil. The second number refer to the viscosity enhancers. The base oil follows the standard tables for "thinning out" with temperature. The enhancers make the oil act like it is thicker when it gets hot. The enhancers are supposed to follow the SAE guidelines but there are differences between manufacturers and types of oil. Multi viscosity oils allow us to drive over a wide range of temperatures without changing oil.
That being said, the engine build is set up with internal tolerances that dictate the weight of oil for different temperatures. A loose race engine will have large tolerances and will "wind" faster and have less internal friction; but will need a higher base weight oil (often a strait 50w).
The other consideration is the other additives in the oil. Race oils have different properties than street oils and are designed for short term use. Do you change oil after each track session? Do you have a track built engine?
Ok, so I got wound up and spent four cents.

[glamcem]

Originally Posted by Element Tuning

Just remember you should run what you need for how you run your engine. Street guys and NA guys just don't have the need for the higher oil pressures and they don't see the elevated oil temps. As a rule of thumb you have more oil pressure, as the OP shows, with cooler than hotter oil temps.

Know what your oil pressure needs are, get an oil pressure gauge, monitor pressure, and adjust viscosity as needed to get the oil pressure you need. Oil brands matter but you will find that Amsoil, Red Line, and Motul often stay in grade better than chain store oil brands as the temps rise. Nerd data is out there comparing viscosity at very high temps and some are just way better than others.

two things I am trying to understand:

Why do you say that NA guys don't need higher oil pressures say for instance at 270F degrees? Since both NA or FI suffer from the same oil pressure issue at the given temp regardless of the power levels.

What makes you think that those brands stay better? Mobil 1 5w-30 provides equal or better viscosity grades than those brands you mentioned at 1/4 of the cost

[glamcem]

@PST forgot to ask; How did you gather this data? by merging Aim MXL2 data with oil pressure gauge readings? The chart looks like a "plotted dot " vs a "sparkline"graph.
I am having hard time understand why the fluctuations are Huge within the same temps ( e.g 16psi/kRPM vs 7psi/kRPM at 240F)

Thanks again for sharing

[GSpeed]

Originally Posted by glamcem

@PST forgot to ask; How did you gather this data? by merging Aim MXL2 data with oil pressure gauge readings? The chart looks like a "plotted dot " vs a "sparkline"graph.
I am having hard time understand why the fluctuations are Huge within the same temps ( e.g 16psi/kRPM vs 7psi/kRPM at 240F)

Thanks again for sharing

Oil pressure was gathered with an AEM pressure transducer in the galley on top of the block. The engine oil temp was reported by the OBD2 channel, which explains the vertical striations in the data. Low resolution.

The differences across a given temperature could be any number of things. We'd have to go back and look at other channels like speed, water temps, etc. to guess what it might be. That's a lot of work, and that's why trends are useful.

[glamcem]

Originally Posted by PST

Oil pressure was gathered with an AEM pressure transducer in the galley on top of the block. The engine oil temp was reported by the OBD2 channel, which explains the vertical striations in the data. Low resolution.

The differences across a given temperature could be any number of things. We'd have to go back and look at other channels like speed, water temps, etc. to guess what it might be. That's a lot of work, and that's why trends are useful.

I see, still very interesting though

Will you be able to create the same graph by holding the engine speed constant at 7000 RPM? so it doesn't have to be the psi/kRPM at that point and we can only use PSI values.
you may also provide the raw data (table) if possible

[kster1]

Originally Posted by glamcem

Do you guys recall your average RPMs during the session? driving style is the most important contributor when it comes to the oil temps.. don't get me wrong but if you guys never really pass 230F mark (even with an oil cooler) on a hot day, you probably don't push the car as much..

My data is here from a Thunderhill event on March 21, 2015. I believe my best laptime was a 2:08 from that day which is pushing a naturally aspirated car fairly hard. I do avoid track events in the peak summer which keeps the car running cooler.

http://photos.imageevent.com/kster1/...tc/aimData.JPG