In other way 2009 BT-50 won’t be used quite long and efficiently. Only Red antifreeze type is suitable and you’ll need 8.8-9.4 liters of it. It’s better to choose fluid in combination of 2008 year, 2.5 volume of motor and engine code of WLAA. It’s important to provide cooling for Mazda’s engine with 2.5 liters volume. There are some conditions in servicing cooling module at Mazda BT-50.
A lot of WLAA motors are used long in Mazda cars but only with good service. So better use Mazda’s advice for servicing 2007 BT-50. If you choose other than Red coolant or use less than 8.8-9.4 liters, you can’t expect normal work. 2.5 BT-50 motors of 2008 year will serve more by optimal service.