I wouldn’t go beyond the Toyota recommendation and if you do lots of short trip driving even cutting the mileage between changes to 3K mile intervals will probably increase longevity. When a car is driven on short trips of only a few miles at a time the engine never reaches full temperature and doesn’t burn off the moisture which contaminates the oil. My cars recommend 5K mile intervals and this is what I use on most of them, but my '97 Escort wagon gets the oil changed every 3K miles, because it is used basically for long distance driving and often the same oil stays in the crankcase 1-2 years. There are lots of people who drive 10K miles between synthetic changes, but their cars often begin using oil at an early age. My '88 Escort has probably averaged 3-5K mile change intervals since new, it didn’t begin using oil until between 250-300K miles and currently the original engine which has never been rebuilt has 518,700 miles, it’s still running and when I last checked compression on it a couple years ago all cylinders were still in the 150 PSI range.