Do your first oil change at 3000mi. It will be pretty black & nasty by then anyway. From then on, it's your call on the interval. IMHO, 7500 is too long for these engines. Their are reports of those who follow extended drain intervals when running the $4-$5/qt synthetics, while doing just filter changes in between. I dont go more than 4K or so even w/ synthetic. G/luck.