Vehicle air con machines are used to test and refill the refrigerant gas in vehicles. There are some important changes in regulations regarding using the correct gas, so it is important to note that in 2017 all test stations need to be using the new HF01234yf gas in place of the existing R134a. From the beginning of 2012 all new vehicles will have the new gas in place. This change is due to the new gas being more environmentally friendly and economical.