12.7 gals or 48 litres
You can get a 1999 Mazda Miata fuel cap at any auto parts store.
A 1991 Mazda Miata has a fuel tank capacity of approximately 11.9 gallons. This allows for a good balance between weight and driving range, which is ideal for a sports car.
The fuel tank capacity of the miata is 10-12 gallons, depending on which model year you own. My 1990 has a 10 gallon tank.
The 1999 Mazda Miata is a returnless fuel system. It has a Fuel Pressure Regulator in the tank (above the fuel pump), and a snub at the end of the fuel rail.
The 2002 Mazda MX-5-Miata runs on regular unleaded.
The 2003 Mazda MX-5-Miata runs on regular unleaded.
The 2004 Mazda MX-5-Miata runs on regular unleaded.
The 2001 Mazda MX-5-Miata runs on regular unleaded.
The 2005 Mazda MX-5-Miata runs on regular unleaded.
in the tank
The 2007 Mazda MX-5-Miata runs on premium unleaded (required).
The 2013 Mazda MX-5-Miata runs on premium unleaded (recommended).