Hi. I have a short trip to work. I drive about a mile each way. Sometimes the temp. gauge just gets up to the normal reading before I shut the engine off. When not driving to work, I use my vehicles to run around town. it's a small town, about 8500 pop. I also run to a bigger town about 30 miles away, every once in a while. My vehicles are a 1993 Chevy Silverado, with a 350. And a 1999 Blazer with a 4.3. I use Quaker State High Mileage oil in them with quality filters. I was planning on doing a OCI twice a year - in April & October. What do you guys think?