For sufficient use of Peugeot 307 you need to use suitable antifreeze. For 2008 307 engine it’s necessary to get normal temperature balance. It’s important to provide cooling for Peugeot’s engine with 1.4 liters volume. It’s important to use 8.3 liters of coolant which has Red color. In 2004 the company produced vehicles with 2.0 engine having code of RFN(EW10J4).
It’s obvious that every 9HY (DV6TED4) motor needs good service as stated by Peugeot in instruction. Look at Peugeot’s requirements and make your 2003 307 serve longer and with no problem. Providing you keep the rules 1.4 motor installed in 307 of 2007 year will be long lasting. To endure car life take only Red antifreeze and pour not more or less than 8.3 liters.