My 96 accord ex has been using mobil 1 (usually 5w-30) since 5k miles. My brother was the first owner and the car now has 82k miles. The first 6 years was spent in Buffalo so there were a lot of cold starts. I took over at 60k miles. The valves are still very quiet and it has never had valves clearence adjustment done since new. The car doesn't use a drop of oil between 4k miles oil changes and there is no leaks as far as i can tell. I think i will keep using it since it really doesn't cost much more than regular oil. May be about 13$ more each change and it take about 4.5 qt.