I'm on flight AWE574 right now, SJC-PHX-TPA, and it's a A319 with Wifi. Neither the reservations page nor the flight status reflect this ship having wifi, yet it clearly does.

Is there a reliable way to figure out whether or not a plane actually has wifi? I changed a flight to fly PHX-JFK instead of PHX-EWR specifically because PHX-JFK was a A320 that shows Wifi on the reservations page.