Our daughter is now driving our 1988, yes, 1988 Honda Accord with over 300,000miles on the clock. This car has been very well maintained by me and the OCI has been 3-4000 miles using the dino recomended 5W30 -10W30 motor oil. Purchaced new, this car has been driven up and down the east coast over the past 17 yrs between NY & FLA. Our daughter is complaining about her out of pocket $$$ at the fuel pump. The engine is in good tune and I have performed good MPG practices on the car over the years. The fuel economy is still the same when new, beleive it or not and the engine does not burn or leak any oil. I'am currently using 5W20 motor oil for the most recent oil/filter change only to see if the MPG will increase. My daughter driving habits consist of to and from high school and work. Both trips consist of aprox.5 miles each way. She also does a little running around with friends to malls and school activities. All trips are very short distances with long engine shut downs between restarts. Should I be concerned with the 5W20 motor oil or should we just stick with what has worked over the years....Responces Please!