OK, thanks guys. I drive about 45 miles per day on the highway, maybe 10
around town. I changed my oil today, and found that my oil plug seal was
crumbling. I didn't pay any attention to it last time, so it could have
been leaking a small amount accounting for some of the oil usage. I have
oil spots all over my driveway from oil changes :) so I never noticed any
leakage if there was any. How do y'all find out what kind of mileage you
get on hwy vs. city?