Does The 2013 Synthetic Oil Change Interval Make Sense?

Oil formulation now is superior compared to what they were even 5 years ago. Conventional dino oils now have also most the same thermal resistance and cleaning power of synthetics from two or three API formulations ago. Even in 100% stop and go traffic - even 5K miles won't make dino oil break a sweat. Not unusal to see dino oil run 7000-8000+ miles on a change under ideal conditions.

If someone wants to push 10K miles or beyond - that's a little more demanding, even with synthetics. Issue is not really with the oil, but with filtration needs. Eventually, the oil will become saturated with insoluables and will no longer be able to keep those particles suspended in solution. When they fall out - they turn to sludge. Even synthetics will see this at some point exactly when this happens, depends on the driving conditions and the engine.

I'd go ahead and tell the dealership to go to a more conservative oil change - if you feel you like that interval better. There is no one mileage fits all here - it is whatever fits your budget and your comfort level for maintenance. Running an oil change interval with synthetic motor oil - a non-issue IMO - any synthetic will be able to handle that, assuming that the engine is running well.