I've never put too much thought into oil weights.
I wouldn't personally do this, but my mechanic does the following; uses 20w50 for everything! It never gets cold here in Phoenix but still I always thought he was crazy for doing this.
Anyways, he services countless Towncar's(4.6), many of them have 200-500,000 miles. All of them on 20w50 oil! Mind you these cars call for 5w20. My preference here in AZ is 10w30 which isn't "thick" with the exception of my 2000 Corolla that burns oil. It will see whatever, for a while Delvac 15w40, thanks to the BOGO at Checker's.
I wouldn't personally do this, but my mechanic does the following; uses 20w50 for everything! It never gets cold here in Phoenix but still I always thought he was crazy for doing this.
Anyways, he services countless Towncar's(4.6), many of them have 200-500,000 miles. All of them on 20w50 oil! Mind you these cars call for 5w20. My preference here in AZ is 10w30 which isn't "thick" with the exception of my 2000 Corolla that burns oil. It will see whatever, for a while Delvac 15w40, thanks to the BOGO at Checker's.