Oils tested: 10W-30 Ultimate Durability (UD), 0W-20 Ultimate Protection (UP), 5W-20 UP, 5W-40 UP
These oils were purchased in the United States. 10W-30 UD was bought several years ago. The UP oils were bought a few weeks ago.
1.000 grams of each oil was placed in separate, small aluminum cups. No oil was allowed to get on the sides of the cups since that would influence the results. Oils were heated in a toaster oven with a single sheet of aluminum foil covering the tops of the cups to prevent the intense radiation from reaching the oils. Oils react to radiation which I wanted to minimize. The walls of the cups have a large single opening that goes roughly halfway down the cup, so evaporated oil does freely escape the cups even when the tops are covered. The oil temperature was increased throughout the test due to a concern of autoignition. A thermocouple was used to measure the temperature the oils would start at with by measuring the temperature of an oil sample NOT included in the test. Measurement was 332 F. Calibration tests conducted on the thermocouple were done at house thermostat reading at 70 F and thermocouple said 70 F. Boiling water at 150 feet altitude read at 206 F, so it was ~ 6 degrees low. So, the 332 F measurement was probably low by > 6 F.
The four cups of oil were placed fairly close to the glass door and the cups’ openings faced toward the glass. Reasons for that is to keep them away from being directly above the heating element and to keep the cup openings facing the region of least radiation. The scale used is “My Weigh” Model i101 with resolution of 0.005 grams. When it oscillates between two weights and spends roughly equal time between them, I go with a weight 0.002 above the smaller weight.
Graphs showing the cumulative weight losses and relative cumulative weight losses vs measurement number are below. The relative data is relative to 10W-30 UD since that had the lowest volatility. Keep in mind that the temperature did increase throughout the test and the ambient temperature varied as well. Increasing temperature obviously has a tendency to increase the amount of mass loss. I was seeking relative mass losses, so the changing temperature is not a problem. The reason for increasing the temperature is that the test later transitioned into the deposit forming phase and I wanted to decrease the amount of time it would take for deposits to form.
MSDSs of all four oils list only GTL as base oils and it comprises the vast majority, if not, the only base oil. Therefore, the combined viscosity of the one or more GTL base oils in each product is is likely the primary driver of the volatility. The volatility results make sense to me from what I expect the combined base oil viscosities to be. I have not used Gokhan's base oil viscosity calculator on these oils but I did see that 10W-30 UD has a combined base oil viscosity near the upper end of all of the oils in his database. That, combined with GTL chemistry, yields low volatility. I did not test 10W-30 UP, because I have not been able to find a source for it. Quaker State has not yet responded to my message asking if it is indeed being sold.
These oils were purchased in the United States. 10W-30 UD was bought several years ago. The UP oils were bought a few weeks ago.
1.000 grams of each oil was placed in separate, small aluminum cups. No oil was allowed to get on the sides of the cups since that would influence the results. Oils were heated in a toaster oven with a single sheet of aluminum foil covering the tops of the cups to prevent the intense radiation from reaching the oils. Oils react to radiation which I wanted to minimize. The walls of the cups have a large single opening that goes roughly halfway down the cup, so evaporated oil does freely escape the cups even when the tops are covered. The oil temperature was increased throughout the test due to a concern of autoignition. A thermocouple was used to measure the temperature the oils would start at with by measuring the temperature of an oil sample NOT included in the test. Measurement was 332 F. Calibration tests conducted on the thermocouple were done at house thermostat reading at 70 F and thermocouple said 70 F. Boiling water at 150 feet altitude read at 206 F, so it was ~ 6 degrees low. So, the 332 F measurement was probably low by > 6 F.
The four cups of oil were placed fairly close to the glass door and the cups’ openings faced toward the glass. Reasons for that is to keep them away from being directly above the heating element and to keep the cup openings facing the region of least radiation. The scale used is “My Weigh” Model i101 with resolution of 0.005 grams. When it oscillates between two weights and spends roughly equal time between them, I go with a weight 0.002 above the smaller weight.
Graphs showing the cumulative weight losses and relative cumulative weight losses vs measurement number are below. The relative data is relative to 10W-30 UD since that had the lowest volatility. Keep in mind that the temperature did increase throughout the test and the ambient temperature varied as well. Increasing temperature obviously has a tendency to increase the amount of mass loss. I was seeking relative mass losses, so the changing temperature is not a problem. The reason for increasing the temperature is that the test later transitioned into the deposit forming phase and I wanted to decrease the amount of time it would take for deposits to form.
MSDSs of all four oils list only GTL as base oils and it comprises the vast majority, if not, the only base oil. Therefore, the combined viscosity of the one or more GTL base oils in each product is is likely the primary driver of the volatility. The volatility results make sense to me from what I expect the combined base oil viscosities to be. I have not used Gokhan's base oil viscosity calculator on these oils but I did see that 10W-30 UD has a combined base oil viscosity near the upper end of all of the oils in his database. That, combined with GTL chemistry, yields low volatility. I did not test 10W-30 UP, because I have not been able to find a source for it. Quaker State has not yet responded to my message asking if it is indeed being sold.
