Normal radiator work is needed in Mazda 5 for optimal output. For changing this part in 5 buy only factory size: 650 mm of height, 370 mm of width and 16 mm of depth. The motor with volume of 1.8 from year 2008 has strict antifreeze temperature. In Mazda’s production you won’t try to fix radiator made in 2005. It’s impossible to install in Mazda 5 2.0 radiator with different dimensions.
It’s better for Mazda cars produced in 2012 to investigate cooling system every regular service. Buying a new radiator for 2011 Mazda 5 better choose such dimensions: 650 mm high, 370 mm in width and 16 mm deep. You might need to replace cooling system part in 5 2.0 if you possess the vehicle with RF7J code of motor.