Some clarification: I have an external HDD that gets it power from the USB port. Even if I turn of the computer, the HDD won't shut down, because there's power-off charging on that port. This is my only USB3 port, so using an other port is not an option.
Mobil 1 Extended Performance synthetic oil is recommended for oil change intervals up to 15,000 miles or one year, whichever occurs first. However, if your vehicle manufacturer recommends an oil change interval beyond 15,000 miles and Mobil 1 Extended Performance meets the performance level specified, you can be assured that Mobil 1 Extended Performance will go the distance.
Oil changes are needed frequently to avoid this problem (ergo every 3,000 to 5,000 miles). The durability of synthetic oil at the same engine temperature makes it a better-performing product because synthetic still stays in liquid, usable form longer. This tolerance for temperature means the oil can stay in the engine and can last as much as 7,000 miles before changing. Most oil and car warranties will put the maximum length of mileage before a change at 7,500 for petroleum-based products (many cars are closer to 5,000 even with today's better engines). Given the heat-tolerance properties of synthetic oil, 7,500 miles is not an issue.