One thing to consider is that our cars have 8.5 quarts in the engine, meaning you should be able to go further between oil changes than cars using half the oil. And also these tests are usually done on cars with 5 quarts or less and are normally aspirated, so the extra quarts make a huge difference. Normally aspirated cars should go further on oil than forced induction ones. Just play it safe and change it every 7000 like the manual says...No need to change every 3000 unless you are using non-syntheticss which would be a no no with our cars. But then again, if you have the money to throw away, change it as often as you'd like. I always liked seeing clean oil on my dipstick!