My grandmother has a '98 Buick Century 3.1 V6. I changed the oil in it a year ago(Pennzoil YB and Pure One) and haven't touched it since other than checking the oil level. I only change the oil once a year because the car only goes to the supermarket on Fridays and church on Sundays. The car is lucky if it sees 1k per year. She called me yesterday and told me that the "Change Oil Soon" light had come on. Could it be that all the short trips are being hard on the oil and that is why the light has suddenly come on? I've heard that the lights have a habit of coming on early. Any help would be appreciated.