I would be careful about switching weights. I am not saying that you can't change weights, just do your homework first and make sure that the new weight oil matches the recommended factory specifications listed in your owners manual. Some oils have higher levels of a compound called ZDDP and other additives that will clog your catalytic converter. This happened to me by switching from 5W30 to 15W40 oil. It took about 40,000 miles for it to happen. I found out how this happened by reading an article in Hot Rod magazine a few years ago. The newer style oils have synthetic compounds that burn cleaner for catalytic converters and oxygen sensors. Hope this info helps.