[Halon]

Like I said I would not run 20W-50 in a daily/street driven DSM personally. I run 5W-30 in mine, and mines a summer only driven street car here. If you're concerned about the higher temps, then like I said consider going up to say a 5W-40 or 10W-40. If you're really wanting to make a science experiment out of it, get an oil temp gauge as that will be the best tool to tell you what weight to get for your application.

Remember that your oil doesn't even get to operating temp until you've been driving say 20-30 minutes under normal conditions. So if you're just taking 20-30 minute trips, your oil is barely even making it to it's operating weight anyway.