The honest answer is that it depends on the engine, the oil and the climate, and that the 3,000-mile rule you grew up with has not applied to a modern car in a long time.
What the manufacturer says
Most modern European engines are designed around intervals somewhere between 7,500 and 15,000 miles, and many calculate the interval themselves rather than counting distance. BMW and Rolls-Royce use Condition Based Servicing, Mercedes uses ASSYST. Both weigh cold starts, load, temperature and driving style.
Those calculations were validated for a mixed duty cycle in a temperate climate.
What we recommend in South Florida
7,500 miles or twelve months, whichever comes first.
Heat is the reason. Sustained high ambient temperatures, heat soak after short trips and stop-start traffic all age oil faster than steady highway miles. A turbocharged engine works it harder still, because the turbocharger is cooled by the oil passing through it.
Running shorter here is not an upsell, it is correcting for conditions the schedule did not model.
Synthetic versus conventional is not really a choice anymore
On any modern European engine it is not optional. These engines were designed around synthetic oil carrying a specific manufacturer approval, and the turbochargers, timing chains and variable valve timing all depend on it behaving predictably when hot.
More importantly, the approval matters more than the word synthetic. BMW publishes Longlife specifications, Mercedes publishes MB approval sheets, VW and Audi publish 502 00, 504 00 and 508 00, Porsche publishes A40. An oil can be fully synthetic, the correct viscosity, and meet none of them.
Things that shorten the interval
- Mostly short trips, where the engine never fully warms
- Towing or carrying heavy loads
- Track use of any kind
- Long periods parked, since oil degrades with time as well as distance
What should come with it
The car is on the lift anyway. Every oil service here includes a full digital inspection of brakes, tires, suspension, belts, cooling and leaks, photographed and graded. Most of the expensive work we do started as an amber item somebody photographed a year earlier.
Call (561) 392-1910 with your VIN and we will tell you the exact specification your engine takes. See synthetic oil change for what is included.