Out of all the popular cities in Thailand, Bangkok is the cheapest city to rent a car in at just ₱704/day. Renting a car in Bangkok is 61% cheaper than renting one in Chiang Mai where the per day rate is around ₱1,824. Other fairly inexpensive cities in Thailand to get a rental car in are: Koh Samui (₱817/day), Phuket City (₱1,289/day), and Chiang Mai (₱1,824/day). While these cities typically have cheaper prices than the rest of the country, travelers looking to rent a car in Bangkok should expect to spend around ₱704/day on their transportation. The most popular city to rent a car in Thailand is Bangkok.