I am doing them every 5000 miles now, next one due this weekend at 10,000. Using Mobil One synthetic. The 6.2 does not take a full 7 quarts, it's more like 6.5, check it after putting in 6 then add the extra needed. There was a thread on here about that, I checked mine and it was overfull, but I'm not going to try to let any out for only 1/2 quart. I know the book says 7 but they need to round up to be safe.