Engine light is ON

I change my oil religiously every 5k miles. Have for years after replacing an engine at 100k miles. I'd rather overpay for maintenance than suffer the possible consequences. Every "when you should change" write-up I've seen has a definition of "severe service" which describes how most people use their car. Lots of starts and stops and varying temperatures and creeping along in traffic. If I were solely interstates, I'd go with the longer intervals which I'm convinced are there just so they don't get dinged by car reviewers in magazines who compare maintenance costs among other things. They also get rid of their cars after a year before the wear really shows. I keep mine for around 10 years.