Currently have a 2002 Accord EX. Everytime I need to get an oil change the walmart or wherever I wanna go never has 5w-20 oil, thus making me goto Honda for the oil change. Why is it necessary to put 5w-20 in the car? Hardly anybody has it anymore

 

5W-30 Castrol GTX or synthetics will work just as well. The important spec (or number you should watch) is the first (5w), particularly in Pennsylvania in the winter. Too high a number and the oil will thicken during cold morning start-ups.
In the hot summer months, 10W-30 has been a traditional Multi-grade oil. (It acts like a 10W when cold, a 30W when warm.
Honda's theory on Oil Viscosity is the thinner gives better milage, but you'll hardly notice it (Really)

P

 

i run 20-50 Lucas in the summer time and
10-40 in the winter but i also change my own oil.