If you drive in a high alt. Hot air vs. cold air makes a difference too. The colder air requires more fuel to maintain the proper mix which yeilds less mileage. I hope this helps a bit. Tires, tire pressure, and possible vacuum leaks would be the most obvious places I would investigate for, what seems to me to be, mediocre mileage.
Every engine is different.
Even engines of the same make and model and year from the same assembly line have variations. If you drive in a high alt. Hot air vs. cold air makes a difference too. The colder air requires more fuel to maintain the proper mix which yeilds less mileage. I hope this helps a bit.