Picking the best motor oil is extremely important to the life of your engine. By popular demand I have written up the tested comparison between Amsoil and Mobil 1 Extended Performance. To keep your engine clean, extend engine life, and get the most horsepower pay attention…
When trying to test a motor oil for its load wear protection capability you can consider the results of a 4 ball wear test conducted according to ASTM D-1472 at 1200 RPM. This test takes a spinning ball at 1200 RPM and forces it into three other stationary balls (forms a pyramid) submerged in an oil bath. After 1 hour the balls are taken out and the wear scar is measured.
Amsoil had a wear scar diameter of .35mm where Mobil 1 had a wear scar diameter of .44mm. Amsoil is the clear winner of this test.
Thin film oxygen uptake testing per ASTM standard D-4742 demonstrates an oils ability to resist oxidatation. The longer the oil can withstand this test the longer an oil should be capable of protecting your engine. AMSOIL scored 489 minutes vs Mobil 1 at 383 minutes. This indicates AMSOIL would last longer in an oxidizing environment like that found in your engine. AMSOIL is the winner on this one.
NOAK volatility testing per ASTM D-5800 demonstrates an oils tendency to evaporate. As you can imagine you don’t want your oil vaporizing inside your engine. AMSOIL scored a low 5.7% weight loss as compared to Mobil 1 at an 8.2% weight loss. Again AMSOIL scores ahead of Mobil 1.
Total Base Number Testing per ASTM D-2896 demonstrates an oils ability to neutralize an acid environment. If you don’t neutralize the acids inside your engine it will get eaten alive (from the inside out). AMSOIL came in with the highest number of all oils tested at a shocking 12.2 mg KOH/g with Mobil 1 trailing behind at 10.3 mg KOH/g. The higher the number the better. If acid corrosion protection inside your engine is all you care about then AMSOIL takes the lead here.
Cold Cranking Viscosity tested per ASTM standard D-5293 at -25C. A couple things happen in cold weather that make it difficult and torturous to start an engine. First the amp capability of your battery is diminished and second your oil can get too thick. Thick oil doesn’t just make it difficult to start your engine it also prevents free flow of oil through the engine after its started! Scary considering all the moving parts that may not have lubrication. If an oil can keep from getting too viscous at low temperature it will help your engine start easier and make sure oil is flowing right away. AMSOIL tested in at the lowest with a viscosity of 4150 cP and Mobil 1 not too far off with a viscosity of 4719 cP.
To take the concept of cold one step further we have the very extreme test to determine when an oil will even flow. To test this ASTM standard D-97 Pour Point test was used. Amsoil and Mobil 1 tied on this one at an astonishing -54F pour temperature. Obviously you should have your block heater on at these subzero temps but if you didn’t this guys flow at the lowest temperature of all the oils tested.
When choosing the right oil for you car or truck cost is also a consideration. If money was no object we would all run the most premium oil we could find. That is why at the time of the testing the cost per 25,000 miles of operation was documented. AMSOIL was estimated to cost $44.50 per 25,000 miles and the Mobil 1 was $72.90 per 25,000 miles. There is a big difference to consider there…
AMSOIL topped Mobil in this set of test data. If you would like the color charts and motor oil test data for all the top brands then get your free motor oil report here at best motor oil review.