scheduled -300s to California from Newark.
One of the things that folks have to keep in mind when attempting to make these kinds of comparisons is that all 737-300s (or any other type/variant) are not necessarily created equal. While they appear identical on the outside (paint jobs excepted) a CAL 737-300 and a SWA 737-300 could easily have different engine ratings, fuel tank capacities, and weight ratings such that one had different operational capabilities than the other.
A good historical example is the 737-200.
737-200 "Basic" -7 engines
737-200 "ADVanced" -9 engines
737-200 "ADVanced" -15 engines
737-200 "ADVanced" -17 engines
In rough comparions, the -17 powered ADV could fly to Mars, whilst the -7 Basic could barely get out of its own way and was basically a 1-2 hour aircraft. Yet, to the naked eye, all four of the above look pretty much the "same"
I ran a PHL
flight plan on a -300 the other day, and while the takeoff performance at PHL
and the landing performance at LAX
were not problems, I got a "NEED MBF" error message which meant the headwinds that day were such the fuel required to make the flight (plus reserves) exceeded the tank capacity of the aircraft. Since Boeing hasn't yet certified "drop tanks" for the 737, the only two options were to fuel-stop enroute, or swap to a -700 (which has a bigger tank capacity), and we did the latter.
ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.