15,000 + miles between oil changes, really? When your BMW was covered under a maintenance plan and BMW was paying for your oil changes, this was great for them, but not for your BMW. In a perfect environment, this interval might be ok. If you factor in humidity, varying temperatures (especially in New England), and different driving styles, your oil will certainly start to develop sludge and lose its lubricating ability. On many newer models, BMW has recently reverted back to a 10,000 mile interval. My recommendation on oil change intervals is every 6 months or 7,500 miles.
BMW Service Icons: You may see these on your dash when your car is due for service. Starting in 2006, most BMWs went from following a traditional mileage based service to a conditioned based service program. Condition Based Service, ensures your BMW only receives attention when it needs it, saving you time and money.