The other question that should be asked is how many times are you changing your oil during the summer verses the winter. I live in VA, the winters are cold and summer can be very hot. I drive my car a lot specially during car meet season, since I have my weekends off, I usually hit up 3 or 4 cars meets in one day and can put almost a 1000 miles on my car during a weekend run. For me I use 5 w20 year round however, I change my oil more frequent during the summer months (every 5000 miles) and during the winter (every 8000 miles) since my engine does not run as hot. Plus every oil change I put my favorite BG product MOA, for extra insurance year round as well. So far my engine is humming along, no ticks, no loss of power and great MPG. But hay that is my two cents you can use it or lose it, let us know your final out come and how well your engine is performing.
Ford Mustang 2003 Mach1 Torch Red (D3)
8in black antenna / Exceedy Stage 2 Clutch 450
Ford Racing Billett FlyWheel / JLT CAI/JLT OIL CC/MGW SS
17/275-315 Nitto 555 / Offset Semi-Black Gloss Saleen Rims
Pioneer Touch Screen / J&L Amp /2 J&L 10" Subwoofers in a Box/ SLP Catback Exhaust/ BAMA Tuner