If it's not been messed with then the only one that will have a VTEC "D16y8" engine is the EX model which will also have a sun roof.
The air filter is in the right fender well area of the D16Y8 and it's on top of the intake on the D16Y7.
The fuel economy really shouldn't be that different no matter which engine you have if driven nicely.
The parts can be easily swapped around so looking for VTEC on the valve cover doesn't necessarily mean anything.
The engine code is stamped on the front corner of the engine block "standing at front of car" as illustrated in the link below.
This is a B series but the location is the same.
http://honda-tech.com/attachments/ho...c-engcode1.jpg
http://i25.tinypic.com/65yg0o.jpg
or
D16y8.jpg Photo by Hamster_Style | Photobucket