I have noticed after the oil change to ProDS 5w20 my fuel economy has dropped. I used excuse of idling, city driving etc. Have checked everything from computer codes to tire pressure nothing is off. I had a funeral to go to so about 400 miles and again I am off right at 3 mpg on average. I had time today to check bottles and website which now I can say it is oil. The only one that is fuel economy one is 0w20 which states an improvement of a 2% over other grades and 5w20 can be replaced with 0w20 to get fuel savings. All grades are for extended drains with severe driving not fuel economy My situation 60 miles shorter on tank of fuel at 2.50 a gallon is costing me 7.50 a tank so savings on oil is wiped out by 1 tank therefore costing me more money On the the trip before if I set cruise at 70 dash would show high 28 with average of 24.5 so checked this morning and it shows 23.6 and highest I saw was 25.3 and will know exact figure once I fill up but already know it is off. Less than 12k on vehicle with 20.9 average before change and 17 average after change Lowest before change was 17 lowest after was 13 Now do I dump this or wait? 2500 miles on oil since April so I was going to April then decided to change at 5k since mileage is down now I know how much it costs more I just want to cut my losses and dump it. It is a shame cause I don't have any problems other than fuel mileage. Opinions appreciated.