Yep - I used the 9603 plugs and so far have had no issues. The car runs smooth and my mileage has gone from around 18 to about 21 with a mix of city and highway driving. One of these days I will get through a tank of gas without sticking my foot in it so I can see how good of an MPG it will actually give me ... but that's not real high on the list of things to do