Oil Change

[Clipdat]

5.7 quarts

Originally Posted by TRD_86

how many quart of 0w-20 this car need for oil change ?

[Nasty Sausage]

Mobil 1 is totally fine. If you absolutely require a high performance oil, then Amsoil or Motul is probably the better choice over Mobil 1. I am not a salesman, but here are my thoughts and a brief analysis as a humble physicist:

Motul has a flash point of 428*F, Mobil 1 is at 435*F, and Amsoil's flash point is at 450*F. The kinematic viscosity at 100*C for all three is 8, 8.7 and 8.8, respectively. The TBN's are 11.3, 8.8, and 12.6, respectively.

So in theory, Amsoil is more resistant to burning, is a little thicker at operating temperature, and has the higher resistance to acid chain formation compared to the other two since it has a higher alkalinity rating. So, as my legal writing teacher with bitchy resting face frequently asserted, "How does this affect me, and why should I care?"

If you change oil every 7k miles, it doesn't and you shouldn't, but if you go up to 15 or 20k miles between intervals, I'm unsure that the other two options would last quite as long. Motul will and does last a while, having a TBN of 11.3 and all, but the flash point is 22*F lower so it will burn off sooner in extreme conditions. In a racing application, a Δ of 22*F is very significant in terms of operating temperature leeway when comparing these three. Will most of us ever notice or require this? Absolutely not.

I hope this helps the OP choose the right oil, and if anyone dissents, even an iota, kindly offer your discourse.

[bluesubie]

Originally Posted by Nasty Sausage

Mobil 1 is totally fine. If you absolutely require a high performance oil, then Amsoil or Motul is probably the better choice over Mobil 1. I am not a salesman, but here are my thoughts and a brief analysis as a humble physicist:

Motul has a flash point of 428*F, Mobil 1 is at 435*F, and Amsoil's flash point is at 450*F. The kinematic viscosity at 100*C for all three is 8, 8.7 and 8.8, respectively. The TBN's are 11.3, 8.8, and 12.6, respectively.

So in theory, Amsoil is more resistant to burning, is a little thicker at operating temperature, and has the higher resistance to acid chain formation compared to the other two since it has a higher alkalinity rating. So, as my legal writing teacher with bitchy resting face frequently asserted, "How does this affect me, and why should I care?"

If you change oil every 7k miles, it doesn't and you shouldn't, but if you go up to 15 or 20k miles between intervals, I'm unsure that the other two options would last quite as long. Motul will and does last a while, having a TBN of 11.3 and all, but the flash point is 22*F lower so it will burn off sooner in extreme conditions. In a racing application, a Δ of 22*F is very significant in terms of operating temperature leeway when comparing these three. Will most of us ever notice or require this? Absolutely not.

I hope this helps the OP choose the right oil, and if anyone dissents, even an iota, kindly offer your discourse.

First, you should mention the specific oil that you're discussing for those that are following along. These manufacturers make more than one oil and more than one 0W-20 (except that there's only one M1 0W-20). On the Amsoil, I presume that you're referring to the non-API certified Signature Series ASM oil and not the Amsoil OE or XL. Of course, anyone that pushes their intervals beyond the manufacturers recommendations isn't too concerned about running API certfied oil anyway (I know an Outback owner that has run the Signature Series for 12k mile intervals from the moment he drained the factory fill). The Flashpoint of Motul 8100 0W-20 Eco-lite is not 428*F, but 460.4*F, so please check your info:
http://www.motul.com/system/product_...pdf?1375489501

Second, generally speaking, you're probably right about choosing an oil with a high TBN if you want to run extended intervals. Although, simply looking at a TBN on a data sheet doesn't tell you the rate that the TBN drops.

If oil "A" has a TBN of 10 and oil "B" has a TBN of 6, is there a guarantee that the TBN of oil A will drop at the same rate as oil B? No. Both oils may end up with a TBN of 2 at 7,500 miles, or maybe the TBN of oil A will drop more quickly than oil B.

Also, Flashpoint doesn't tell you the temp. at which the oil will "burn off" in your car.
http://www.astm.org/Standards/D92.htm
NOACK volatility is probably a better indicator since it is a measure of evaporation. http://www.pqiamerica.com/noack.htm
Although NOACK is not the sole indicator of burn-off either. Base stocks and additives play a part as well.

I would hope no one is driving around with oil temps of 425+F.

-Dennis

[Nasty Sausage]

I hope no one is driving around at that temperature either! That's reserved for Lambos in flames.

I sure did mean the Amsoil signature series. I am unable to find the NOACK volatility for the Motul 8100 on their website, but Amsoil claims their SS 0W20 is 9.3 %, which is higher than the 9% figure for Red Line 0W20.

I did a UOA on the 5W30 Amsoil SS in my IS300 after 12k miles and the TBN was 8.8, so I don't think that this particular series of oil deteriorates very rapidly, or at least to that point immediately. I did add half a quart over that time. I suppose it could have dropped TBN within the first few thousand miles, but that is probably unlikely. I'm almost certain the 0W20 Amsoil SS will degrade more due to the higher NOACK volatility rating, but I'll find out in 5k miles.

I have little experience with Motul except their excellent RBF660 brake fluid. What is your opinion on the rate at which the Motul 8100 0W20 degrades at, say, 10k miles compared to the Red Line and Amsoil? I am hesitant to try it because I just noticed that they do not publish the NOACK volatility on their website. I know this isn't an end all be all, but it's a decent corollary to the oil stock quality.

[bluesubie]

Originally Posted by Nasty Sausage

What is your opinion on the rate at which the Motul 8100 0W20 degrades at, say, 10k miles compared to the Red Line and Amsoil? I am hesitant to try it because I just noticed that they do not publish the NOACK volatility on their website. I know this isn't an end all be all, but it's a decent corollary to the oil stock quality.

Red Line has never been a long drain oil, although I believe that you can find a few 10k or so uoa's on the 20 grades if you search. And any uoa's on Motul 0W-20 8100 is rare. And most people that use Blackstone don't pay for the TBN.

Motul may provide NOACK info if you ring them up. Google Motul Pomona CA and ask for their Technical Dept.

The king of NOACK is turning out to be some of the SOPUS oils with Pennzoil Ultra and their GTL base stocks having better NOACK than both Red Line and Amsoil among some grades. They only have a 5W-20, which has a 5% NOACK. Of course, TBN is lower than Amsoil but it could probably handle 7,500 mile and beyond intervals.

Oops.

-Dennis

[Nasty Sausage]

Thanks Dennis!

Regards,

Mike

[Mikeez]

How do we change our own oil, I hate mechanics lol =D

[CoupedUpSubie]

Originally Posted by bluesubie

If oil "A" has a TBN of 10 and oil "B" has a TBN of 6, is there a guarantee that the TBN of oil A will drop at the same rate as oil B? No. Both oils may end up with a TBN of 2 at 7,500 miles, or maybe the TBN of oil A will drop more quickly than oil B.

As long as both oils are tested in the same fashion with the same chemicals the oil with a TBN of 10 will last longer then an oil with a TBN of 6. I spent 5 months doing daily oil tests on a ship. Granted this was oil used in diesel engines but the same principles apply. The way the test station I was using determined the TBN was based on pressure after a certain amount of reagent was added to the oil. TBN depletion depends more on driving style and maintenance. Gasoline doesn't create as much acid as diesel does.


On the topic of if M1 is fine. The history of M1 in the performance subaru's has not been good. Go to any forum and you will find someone referencing different failures after running M1 in a WRX/STi. This isn't so much consumption but spinning bearings. Maybe it has been improved but I won't even use it in my beater 95 impreza.

[mav1178]

Originally Posted by Mikeez

How do we change our own oil, I hate mechanics lol =D

http://www.ft86club.com/forums/showthread.php?t=7365

[bluesubie]

Originally Posted by CoupedUpSubie

As long as both oils are tested in the same fashion with the same chemicals the oil with a TBN of 10 will last longer then an oil with a TBN of 6. I spent 5 months doing daily oil tests on a ship. Granted this was oil used in diesel engines but the same principles apply. The way the test station I was using determined the TBN was based on pressure after a certain amount of reagent was added to the oil. TBN depletion depends more on driving style and maintenance. Gasoline doesn't create as much acid as diesel does.


On the topic of if M1 is fine. The history of M1 in the performance subaru's has not been good. Go to any forum and you will find someone referencing different failures after running M1 in a WRX/STi. This isn't so much consumption but spinning bearings. Maybe it has been improved but I won't even use it in my beater 95 impreza.

Please show me some data that all oils with a TBN of 10 will continue to fight acids longer than an oil with a TBN of 6. TBN depletion is non-linear and the rate of depletion will also vary based on base stocks and the oils detergent/dispersant package. Now if you're basing your theory on your uoa's from diesel engines, then it's highly possible. Many diesel oils have a very similar additive packages (the same low calcium, higher magnesium) so I can see the TBN depletion rate being very similar for HDEO's. OTOH, PCMO vary wildly in regards to detergent/dispersant additives.

As to Mobil1, you are wrong that the failures are due to the brand. I'm very well aware of the perceived "problem" as I was on the original i-club (pre-nasioc) since 1999 and continue to be very active on nasioc. The spun bearing issues are from knuckleheads modifying their cars, bad tunes, not checking their oil levels regularly, and using the wrong oil grade for their application.

I've seen guys modify their STI's to 400 whp and continue to use Resource Conserving Mobil1 5W-30. Then they do a rebuild, run RT6, and declare that Mobil1 sucks. Well duh! They should be comparing RT6 to Mobil1 5W-40 Turbo Diesel Truck, not regular M1 5W-30. TDT is thicker than RT6 in all temps. Resource Conserving oils are not ideal for turbos because they have a low High Temp High Shear for fuel economy. I have had a couple of very good uoa's with Mobil1 0W-40 in my modified Forester turbo. There are many other good uoa's out there as well.

Your '95 beater Impreza would probably do very well on Mobil conventional 5W-30. You can find 8k mile uoa's on it at bobistheoilguy.com. Of course, you are welcome to show me some data to prove me wrong instead of believing everything you read on the internet.

What does any of this have to do with the topic? Nothing! It's best to look at data for the FR-S/BRZ.

-Dennis