[LateOnTheBrakes]

I'm running autocross and track days with my car so I'm curious what the ideal number would be. In the past when I built LS engines the bearing clearance dictates what the first number of the oil weight will be. A heavier weight oil sounds great but if you're putting 25w50 ina engine that doesn't have big sloppy tolerances you're just making life harder for the oil pump and possibly losing flow to tiny oil gallies.

 

[TRU-BOOST]

5w30 or 10w30 depending on your climate and time of the year should work. Autocross honestly should be fine with 5w20. The temp doesnt usually get all that high on short technical autocross tracks. 10w30 for full blown extended track days would be my go to. Then just dump it when you are done unless another track day is relatively soon. I dont like running around with track used oil very long (unless it was just autocross).

 

[latapx]

Currently have 5w-30 in it now. Have a track day in January and another in March. Changing the oil after the January event and will get it analyzed. Will base next moves off of that! Never thought of using a 10w-30 but if that will be better track protection I may see myself dumping oil before and after sessions.

 

[Blighty]

And yet at the STI Japan website they specifically sell 0w-40 and 5w-40 for the 2022 BRZ for performance and racetrack accordingly.

Their oil is developed with motul they say, so potentially just a re-brand or only slight changes to the motul line.

 

[LateOnTheBrakes]

Right, which is why I think folks are going the wrong direction with the viscosities they are choosing. Go to a higher second number for more film thickness and protection at high temperature.

 

[TRU-BOOST]

And yet at the STI Japan website they specifically sell 0w-40 and 5w-40 for the 2022 BRZ for performance and racetrack accordingly.

Their oil is developed with motul they say, so potentially just a re-brand or only slight changes to the motul line.

For on a race track and dump it out every race.... Sure. On a street car that gets driven spiritedly, cruises on the highway, sits in traffic... Nope.
A 40 weight oil running at around 200 degrees may as well be asphalt tar in the engine. Its not doing any good. You will be creating more drag and friction making the car slower and take a huge MPG dive. What works on a track with no regard to oil life is not the same as what you want in stop and go traffic for 5000-7500 miles.

 

[LateOnTheBrakes]

It doesn't flow like a 40 weight oil. If you bought an SAE 40 single weight oil it would. A 0W-40 flows like a 0W. It has film thickness and pressure characteristics. It's hard to explain if you haven't had a fluid mechanics class that goes into detail about viscosity. One of the benefits of an ME degree I suppose.

 

[EVASIVE TRUENO]

@TRU-BOOST After catching up on this thread I think not my next change, but the following I'll be going 5w-20 since I do occasional spirited runs on the mountains in my area, car never really sees highway miles. Just cruises around town. etc. (I already have some 0w-20 Motul sitting next to me as I write this)

I have been keeping receipts and logs of everything I do to this car. When it comes to swapping your oil type, does it put you at danger for a warranty claim if something were to go wrong? I don't know if the answer is black and white to that question, it's just something I'm genuinely concerned of.

God forbid something happens and I provide receipts of the "wrong" oil being used in the car.

 

[TRU-BOOST]

It doesn't flow like a 40 weight oil. If you bought an SAE 40 single weight oil it would. A 0W-40 flows like a 0W. It has film thickness and pressure characteristics. It's hard to explain if you haven't had a fluid mechanics class that goes into detail about viscosity. One of the benefits of an ME degree I suppose.

View attachment 18529

View attachment 18530

I manufacture viscocity modifiers, oil and fuel additives and other specialty chemicals for a living. I work closely with OEMS, big and small oil companies daily. I know all about how oil works. A 0w40 is running at a significantly thicker viscocity at our normal operating temperature of about 200 degrees. A 0w20 and 0w40 will flow about the same at cold temps, but as heat increases the they become very different. I have attached the specifications of 2 different weights of castrol edge oil.
1st their 0w20 next is a 0w40 blend the dumb european cars use. You can very clearly see that even at 40c (104f) the 0w40 is already 33% thicker.
By the time it gets up to 100c (212) that widens to 43%.
A little extra viscocity can help in certain situations. Daily driving is not one of those situations.

 

[Blighty]

I manufacture viscocity modifiers, oil and fuel additives and other specialty chemicals for a living. I work closely with OEMS, big and small oil companies daily. I know all about how oil works. A 0w40 is running at a significantly thicker viscocity at our normal operating temperature of about 200 degrees. A 0w20 and 0w40 will flow about the same at cold temps, but as heat increases the they become very different. I have attached the specifications of 2 different weights of castrol edge oil.
1st their 0w20 next is a 0w40 blend the dumb european cars use. You can very clearly see that even at 40c (104f) the 0w40 is already 33% thicker.
By the time it gets up to 100c (212) that widens to 43%.
A little extra viscocity can help in certain situations. Daily driving is not one of those situations.


View attachment 18531 View attachment 18532

All that being true, its still what they recommend.

I don't know the specs of the 0w40 they use, nor what the eact conditions inside the engine are, but STI recommend it for high heat and load scenarios. Otherwise they would of just used a 0w-30 and 5w30 right. Being thicker when its hotter, your crappy blend aside, is probably better and not worse for the application STI is recommending it for.

 

[TRU-BOOST]

All that being true, its still what they recommend.

I don't know the specs of the 0w40 they use, nor what the eact conditions inside the engine are, but STI recommend it for high heat and load scenarios. Otherwise they would of just used a 0w-30 and 5w30 right. Being thicker when its hotter, your crappy blend aside, is probably better and not worse for the application STI is recommending it for.

Agree. I mentioned that previously. Its a track oil. Not a street oil. They dont care if it can hold up to hours of idle time on the freeway, or last 5000+ miles. They are running it 200 miles or less with track duty and thats it. For your average hobbyist that doesnt want to do a $150 oil change every couple hundred miles, I wouldnt use it personally.

 

[Blighty]

All that being true, its still what they recommend.

I don't know the specs of the 0w40 they use, nor what the eact conditions inside the engine are, but STI recommend it for high heat and load scenarios. Otherwise they would of just used a 0w-30 and 5w30 right. Being thicker when its hotter, your crappy blend aside, is probably better and not worse for the application STI is recommending it for.

They have two recommendations. The 0w-40 is still a street blend according to them. The 5-40 one is the track specific one.

They may well have very different additive packs for those applications, entirely apart from the grade.

 

[LateOnTheBrakes]

I manufacture viscocity modifiers, oil and fuel additives and other specialty chemicals for a living. I work closely with OEMS, big and small oil companies daily. I know all about how oil works. A 0w40 is running at a significantly thicker viscocity at our normal operating temperature of about 200 degrees. A 0w20 and 0w40 will flow about the same at cold temps, but as heat increases the they become very different. I have attached the specifications of 2 different weights of castrol edge oil.
1st their 0w20 next is a 0w40 blend the dumb european cars use. You can very clearly see that even at 40c (104f) the 0w40 is already 33% thicker.
By the time it gets up to 100c (212) that widens to 43%.
A little extra viscocity can help in certain situations. Daily driving is not one of those situations.


View attachment 18531 View attachment 18532

Thanks. It's nice to see some actual numbers. I beat the piss out of my car at autocross and the occasional HPDE event so that info gives me something to chew on. The owners manual even says 5W-30 is ok at times. Maybe that is the safer option for heavy use.

 

[chiefproblems]

My understanding has always been you can go lower on the first number and higher on the second number safely. The first number is the viscosity at cold start. The second number is what viscosity oil it behaves like as far as film thickness at high temperature. I would think a 0w-30 or 0w-40 would be ideal if they make it.

from my understanding is you want to match the 2nd number(operating temp viscosity) to match your climate and usage. and the first number being closer to the 2nd number means less additives.

For What It's Worth, i just hit 1000 mi break-in, and my first oil change i put in 5W-20 Mobil 1 Synthetic. the factory oil it came with literally drained out like water, i'm guessing it was 0W-20.

 

[LateOnTheBrakes]

@TRU-BOOST After catching up on this thread I think not my next change, but the following I'll be going 5w-20 since I do occasional spirited runs on the mountains in my area, car never really sees highway miles. Just cruises around town. etc. (I already have some 0w-20 Motul sitting next to me as I write this)

I have been keeping receipts and logs of everything I do to this car. When it comes to swapping your oil type, does it put you at danger for a warranty claim if something were to go wrong? I don't know if the answer is black and white to that question, it's just something I'm genuinely concerned of.

God forbid something happens and I provide receipts of the "wrong" oil being used in the car.

The owners manual says you can use 5W-30 in a pinch. If it ever spins a bearing I would not volunteer the info that you used a different grade oil. That being said oil changes aren't that expensive. If you just have it done every 6,000 miles by the dealer they would have a hard time denying you warranty claims.

 

[EVASIVE TRUENO]

The owners manual says you can use 5W-30 in a pinch. If it ever spins a bearing I would not volunteer the info that you used a different grade oil. That being said oil changes aren't that expensive. If you just have it done every 6,000 miles by the dealer they would have a hard time denying you warranty claims.

Never been a fan of the idea of letting the dealership touch my car. Too many horror stories when it comes to something as simple as an oil change.

I change my oil every 3,500 miles, unless something on this car breaks it will probably have 0 dealer service records. So when it breaks, they'd probably want my own records for proof I've been servicing the car. That was my only concern.

 

[LateOnTheBrakes]

Never been a fan of the idea of letting the dealership touch my car. Too many horror stories when it comes to something as simple as an oil change.

I change my oil every 3,500 miles, unless something on this car breaks it will probably have 0 dealer service records. So when it breaks, they'd probably want my own records for proof I've been servicing the car. That was my only concern.

Yeah, same here. But that is why I was saying let them do it every 6,000 miles. You can always check the drain plug and oil level when you get home. Or if you're really OCD like me you could change the oil again as soon as you get home. I changed mine at 1,000, will do it again at 3,000, and then let them do it at the 6,000-mile intervals.

I'm planning to remove the oil pan, clean up the RTV, put the Tomei oil pan baffle, and seal the oil pan with the Toyota FPIG. I will likely run a slightly heavier oil as well. So, if I ever spin a bearing I will be flatbedding it home to undo all of that work and filling it back up with 0W-20.

 

[vincentyang246]

Never been a fan of the idea of letting the dealership touch my car. Too many horror stories when it comes to something as simple as an oil change.

I change my oil every 3,500 miles, unless something on this car breaks it will probably have 0 dealer service records. So when it breaks, they'd probably want my own records for proof I've been servicing the car. That was my only concern.

I've been doing my own oil change/ tires rotation service as well. But luckily I can log the service through carfax.

 

[latapx]

For those of you that are attending HPDE events. i would strongly urge you to NOT stick to a mileage based oil change interval but rather change the oil based on when you attend HPDE events. Auto-x I'm not concerned about...stick to your mileage interval.
As for viscosity (this is my opinion which may be right or wrong) a thicker oil such as 5w-30 or 10w-30 will not cause engine damage on the track. 0W-20 oil exposed to extreme use (high temps at track) will breakdown and fry bearings. Any oil taken beyond its operating temperature will break down and not properly protect the engine. "Thinner" oils have a lower temperature threshold than "thicker" oils. Its that simple.

 

[vincentyang246]

For those of you that are attending HPDE events. i would strongly urge you to NOT stick to a mileage based oil change interval but rather change the oil based on when you attend HPDE events. Auto-x I'm not concerned about...stick to your mileage interval.
As for viscosity (this is my opinion which may be right or wrong) a thicker oil such as 5w-30 or 10w-30 will not cause engine damage on the track. 0W-20 oil exposed to extreme use (high temps at track) will breakdown and fry bearings. Any oil taken beyond its operating temperature will break down and not properly protect the engine. "Thinner" oils have a lower temperature threshold than "thicker" oils. Its that simple.

Especially when the car doesn't have an oil cooler, it is best to run something is thicker than 0w20. I would even make the argument to get on 5w40 during extreme summer temp(100F° +) on track w/ an oil cooler.