Oups.. used 5w30 instead of 5w20....
04-02-2010, 09:54 PM
#3
Senior Member
I did the same thing when I first bought mine. I got worse fuel mileage with the 5-30. I know it weird and that it shouldn't make a difference, but it did. Went back to normal when I put 5-20 back in.
04-02-2010, 09:55 PM
#4
Resident Dinosaur
I would never use 5w20, I live in CA and its 115*F here in the summertime and it doesnt freeze in the winter. I put 10w30 in my Mustang GT, 10w40 in my Thunderbird, and 20w50 in my F-150.