You can trust whoever you want, all I'm saying is that the oil change interval is made to be short so that you're always on the safe side. If you know the basic car maintenance and can check your car's fluids, you'll realize that at 5k, synthetic oil is still fresh looking. Maintenance from a dealer will help you in the long run when you go to sell your car, but I didn't buy mine - it's a lease. Most people who lease don't give a *BLEEP* about their cars: redline them when they're not broken in, use regular gas, and barely do any service. But I'm not like that, I'm taking care of my car, I just don't feel like getting ripped off by the dealer. No offense to dealer mechanics.