- Jan 3, 2006
After driving around for a little over a week, and actually watching the gas mileage, I can't tell any significant drop going from 5W-20 to 5W-30. I can still get around 32 MPG on the highway, and it's hanging around the usual 24 commuting. This morning it was cool enough to have dew on the car, and normally that would mean some clattering during the warm up. No clattering that I can tell. Since another thread here mentioned some camshaft galling on K-series engines, I might just stick to 5W-30. I was curious to see how much of a hit in the gas mileage it would take, but so far it's looking like almost no difference. Since I keep a spreadsheet of all the gas mileage, I just made a note at the last fuel stop that I changed to 5W-30, so I can see if it actually makes a statistical difference over several tanks.