My car is corolla 2005 model. With full tank of 13 gallons, I make between 250 and 300 miles, translating to by the way 19 and 23 mpg. Manufacturers standard for this car is by the way 30 and 40 mpg.
I notice in the morning when I start the car, it revs to 2000 rev/min and gradually reduce to 1000 rev/min over time.It does not go below this at any time.
I also notice that on normal drive, when the engine speed is 2000 rev/min, the car speed is 60 mph. A friends car goes as fast as 75 mph with same engine speed.
Could these contribute to my unusually high fuel consumption? What can be done to solve this problem?

1000 RPM is a bit high for idle, 2000 seems high for startup but not sure the computer allows adjustment. Changed the air filter recently? Plugs? Oxygen sensor? How many miles? As far as highway RPM, what another car gets is meaningless since you don't know the transmission or differential gear ratios. My 2006 Nissan Frontier with a 4.0 liter V6 and a six speed runs 2,000 RPM at 70 and I get 23-25 highway. People rarely get EPA results for mileage.