No, Toyota does not make the distinction between synthetic oil and conventional oil. Toyota recommends 7,500 mile oil change. Interestingly, Castrol says they don't make the claim that synthetic oil last longer and still recommends the oil change at 3,000 miles. Mobil does not really come out and recommend longer oil changes. Amsoil makes the claim of longer oil change and even gives a warranty. However, when a Lexus customer went past the 7,500 mile oil cange with Amsoil and got sludge. Lexus (Toyota) said he voided the warranty and Amsoil's warranty is not worth the paper it is written on.

Bottom line stick to 7,500 miles when you are under warranty and then take your changes after the warranty with what ever your heart desires.