It's good to see more evidence of M1 mediocrity come out. I'm not trashing them...just want the truth to be known for the consumer's benefit. Here's how the volatility of M1 5W-30 API SM compared to some other synthetics. It's not so great. Could be due to several factors: made up of very thin and very thick basestocks (I'm almost certain this is true); overall basestock mixture viscosity relatively low and decent amount of VI improvers added (true, relative to GC); made up of lesser quality basestocks (Group 3 vs Group 4; not sure). Not shown here but M1 0W-40 does quite poorly in volatility tests so don't get any ideas that M1 0W-40 might be one of the few awesome M1 grades still holding out. It also did poorly in very high temp deposit control in different tests (>400F) than the volatility tests described below. It not only formed a black thin layer of deposit on the walls of the cup but also left behind some fly-________-type spot deposits on the bottom of the cup that were thick enough to be felt by the fingernail.
Volatility Test Procedure (NOT NOACK): 2.00 grams of each oil below were put in separate anodized aluminum cups on a "hot plate" with oil temps at ~340F degrees. Values below are the measured weight loss as a percentage of initial oil weight at 4 and 8 hours. Weights were measured with an Ohaus digital balance (Adventurer Pro AV412) that reads to 0.01 grams; accuracy of measurements below are +-0.5%.
1. Lubromoly 5W-40: At 4 & 8 hours: 7.0% & 12.0%
2. Lubromoly 0W-40: At 4 & 8 hours: 8.0% & 14.5%
3. Castrol Syntec 0W-30 ("Gold GC"): At 4 & 8 hours: 9.0% & 17.5%
4. Mobil 1 5W-30 (API SM version): At 4 & 8 hours: 14.0% & 25.5%
From here: http://theoildrop.server101.com/forums/s...part=1&vc=1
Volatility Test Procedure (NOT NOACK): 2.00 grams of each oil below were put in separate anodized aluminum cups on a "hot plate" with oil temps at ~340F degrees. Values below are the measured weight loss as a percentage of initial oil weight at 4 and 8 hours. Weights were measured with an Ohaus digital balance (Adventurer Pro AV412) that reads to 0.01 grams; accuracy of measurements below are +-0.5%.
1. Lubromoly 5W-40: At 4 & 8 hours: 7.0% & 12.0%
2. Lubromoly 0W-40: At 4 & 8 hours: 8.0% & 14.5%
3. Castrol Syntec 0W-30 ("Gold GC"): At 4 & 8 hours: 9.0% & 17.5%
4. Mobil 1 5W-30 (API SM version): At 4 & 8 hours: 14.0% & 25.5%
From here: http://theoildrop.server101.com/forums/s...part=1&vc=1