Two things about this is they didn't tell you what the viscosity was after 256hrs. And isn't this the older test, being E, and now there is F?quote:
High-Stress Engine Test
An earlier formulation of Mobil 1 was also subjected to an engine test that demonstrates the oxidative stability and wear protection of an oil under high-temperature conditions. This test of Mobil 1 was derived from a Sequence IIIE engine test and was run using a GM 3.8-liter V6 engine with the oil kept at a constant 300° F (149º C) in the oil pan. While the Sequence IIIE test is normally run for 64 hours, this Mobil 1 test was run four times longer. And even after 256 hours, Mobil 1 still provided oil protection.
Keeping in mind that these tests were conducted with earlier formulations of Mobil 1, ExxonMobil engineers are confident that Mobil 1 with SuperSyn™ will provide even greater protection than its predecessors.
Motorsports Vs. Short Trips
More proof of Mobil 1's superiority is its use in racing, both by sponsored teams and by "Mom and Pop" racers who bring out their pride and joy for weekend competition. Mobil 1 is used by the top teams in Formula 1, NASCAR and CART racing to provide the protection and reliability that is needed to win championships. But it isn't just the resistance to extremely high temperatures that has captured the interest of racing teams. They have found that Mobil 1 can actually reduce an engine's internal friction and thereby help it produce more horsepower.
As visible and exciting as racing is, it still does not represent the toughest test of a motor oil. Racing teams warm their engines carefully to operating temperature and change their oil often. Compared to driving in stop-and-go traffic, a 220-mph lap at Indianapolis is easy for a motor oil!
Short trips don't allow the engine to warm up enough to burn off corrosion-producing acids and moisture in the oil. When the engine finally does warm up, excess heat can build up while idling at a traffic light. The slow speeds of city driving don't provide enough airflow to cool things down. Lugging the engine at low speed and the heavy use of accessories like air conditioning put a tremendous strain on the engine.
Also, how can driving 220mph be easier on the oil then stop and go traffic? I know stop and go is hard on oil, but for speeds of 220mph, they must have been refering to M1 15w-50.