I use M1 exclusively in my turbo cars. I promise that the turbocharger shaft, reaches 500 degrees F where it comes in contact with oil, as the metal's color temperature is solidly straw at the bearings edge, tapering to brown near the turbine side seal. Which is 500 deg F.
Is the flashpoint of an oil also relevant? Turbo might be 500 degrees but that doesn't mean the oil is at 500 degrees? One of the attributes of Delvac 5w40 CJ4 is it had a relatively higher flashpoint than others (assuming due to PAO content) which I liked for the turbo diesel F550. Thanks for sharing.
Not sure what this is doing in the diesel oil part of bitog, but OK. Mobil has several videos on youtube where they talk about turbo bearings and heat. Yet, understand Ford says you can run conventional GroupII dino oil in Ecoboost engines, and they are proven to last just fine, with water cooling and oil cooling critical at shutdown time especially.
500F is 260C, so this is not too far from the temp at which NOACK testing is performed (250C). I guess the big difference would be that anything that goes to gas in NOACK testing will be carried away by the air flowing over the pan while it would be confined near a turbo and likely go back to liquid after flowing back towards cooler oil...???
2014 Forester XT, 86000 miles Last Change; M1 5W30 d1G2 Tokyo Roki 15208AA170 filter
Mobil 1 says now it can withstand temps up to 500 degrees. I remember years ago they used to say up to 400 degrees. I can't recall what year they changed it.
When Pennzoil first introduced the PurePlus GTL formulations, their website talked about withstanding temps up to 400 degrees! I thought it was interesting because Mobil used to be about the only one saying that. By that time, Mobil had already saying up to 500 degrees. Looking around the Pennzoil now, I don't see any mention of it anymore.
Same thing with Valvoline, a few years ago, I remember seeing on their website where they said their synthetics withstand up to 400 degrees. Now, I don't see it anymore
It looks like Pennzoil and Valvoline have backed down on their claims. Mobil is still saying up to 500 degrees.
Personally I'd take these claims with a huge dollop of salt.
Can the oil withstand 500°F (260°C) momentarily in a relatively oxygen free environment, like when it zips through something like a turbo bearing? Perhaps. But for sustained periods with lots of hot, oxygen rich blow-by around? I very much doubt it.
Also bear in mind that even if the PAO base could take this level of heat, any ZDDP or HSD VII in the oil markedly cannot without breaking down.
Can the oil withstand 500°F (260°C) momentarily in a relatively oxygen free environment, like when it zips through something like a turbo bearing? Perhaps. But for sustained periods with lots of hot, oxygen rich blow-by around? I very much doubt it. Also bear in mind that even if the PAO base could take this level of heat, any ZDDP or HSD VII in the oil markedly cannot without breaking down.
That is true, apparently backed up by Angela's statements at the 17:00 minutes point in:
I actually didn't know that a vehicle like my 2000 F150 would get really hot,say over 200 degrees. Now my zero turn mower is what I thought would get much hotter than my truck. That's why I use Mobil 1 10w40 in my commercial zero turn mower. I have always used Mobil 1 5w30 in my truck,just because I like using fully synthetic oil.