Depends on your climate conditions. Assuming that the conditions don't get much lower than -15deg celsius, then 33 percent antifreeze should be adequate. purchase 2litres of antifreeze and pour into 4litres of water, drain and refill radiator - BUT LET THE ENGINE TICK OVER WITH THE RADIATOR CAP OFF for a while to get rid of airlocks. Six litres should be adequate for most cooling systems, but if you have serious cold, then 50 percent would be advisable.
On avarage 2500-3500 every six months
The 2014 Mazda MAZDA6 has 16 valves.
The 2010 Mazda MAZDA6 has 16 valves.
The 2015 Mazda MAZDA6 has 16 valves.
The 2011 Mazda Mazdaspeed3 has 16 valves.
The 2009 Mazda MAZDA5 has 16 valves.
The 2013 Mazda MAZDA2 has 16 valves.
The 2008 Mazda MAZDA6 has 16 valves.
The 2009 Mazda MAZDA3 has 16 valves.
The 2014 Mazda MAZDA5 has 16 valves.
The 2010 Mazda MAZDA3 has 16 valves.
The 2007 Mazda MAZDA6 has 16 valves.