Power loss

I drive a 1993 ford escort with just about 100,000 miles on it. When I drive on the highway, I can easily get up to 60-65 miles an hour. But then it tends to lose power causing me to slow to 45 miles an hour before it regains power to go faster again. Can this be caused by a dirty fuel filter? Or is there a more obvious cause for this?

A weak pump, dirty fuel or air filter can cause this problem as can a faulty fuel pressure regulator and/or dirty fuel injectors.

i recently had this exact same problem in a 1998 ford escort lx 2.0 i took it to the shop they had it for two weeks (they replaced spark plugs and wires and cleaned my fuel injectors)and while there it somehow ended up with a cracked piston (they said due to a slipped timing belt) and i ended up with a $2500 rebuilt engine and no one ever mentioned the original problem could have been a old fuel pump/ filter. oh how i wish i knew of this forum before taking my car to the shop.

Something similar to that can be caused by a faulty O2 sensor.