In other way 2003 Boxster won’t be used quite long and efficiently. To maintain cooling system you need 17 liters of Blue coolant. It’s important to provide cooling for Porsche’s engine with 3.4 liters volume. Before choosing fluid note that engine code M96.20 and volume of 2.5 were installed to your car in 1998. For Porsche Boxster it’s important to have optimal antifreeze inside.
To endure car life take only Blue antifreeze and pour not more or less than 22 liters. 2.7 Boxster motors of 2005 year will serve more by optimal service. A lot of M96.22 motors are used long in Porsche cars but only with good service. Look at Porsche’s requirements and make your 1996 Boxster serve longer and with no problem.