Well if it's supercharged, its the 2.3L. If it's the non-supercharged, then its the 2.5L.
Should be a 15" wheel. My 96 was.
The nut size is 32mm
Do a Google search like by asking the same question and you should get many results. The is a sticker on the driver's side door that has the engine displacement,either 2300 or 2500.
The 2010 Mazda Mazdaspeed3 has a 2.3 L base engine size.
The 2009 Mazda MAZDA3 has a 2.0 L base engine size.
The 2008 Mazda MAZDA6 has a 2.3 L base engine size.
The 2014 Mazda MAZDA5 has a 2.5 L base engine size.
The 2004 Mazda MAZDA3 has a 2.0 L base engine size.
The 2006 Mazda MAZDA3 has a 2.0 L base engine size.
The 2015 Mazda MAZDA6 has a 2.5 L base engine size.
The 2011 Mazda MAZDA6 has a 2.5 L base engine size.
The 2005 Mazda MAZDA6 has a 2.3 L base engine size.