Brandon302 said:Why would you only do 5k on a full synthetic? Cheap insurance?
Because the your oil gets dirty independent ofmae performance of the oil. The dirt and addition contaminent compounds that build up in your oil is what causes wear in your engine. The oil itself can last longer than an non-synthetic but the dirt and carbon compounds start building up as soon as you add oil to your engine.
Manufacturers like Audi tell you to wait 10,000 miles. I ownned an Audi TTS (mofified) . I changed oil every 3000 miles or every 5 track hours, whichever came first .