How long does it take for the new Toyota VIOS to clean up the carbon deposits?

It's hard to say, it depends on your use. I'll tell you what carbon deposition is and you'll understand. Generally speaking, it is suggested that car owners should do the disassembly-free cleaning of the air intake system every 20,000 to 40,000 kilometers under the condition of meeting routine maintenance. Carbon deposition can be divided into valve, combustion chamber and intake pipe.