Review
As said in my title, I don't notice a difference between the 2 oils until my engine temperature reaches very high temperatures. At higher temperatures, I find the Shell oil to be better, but not by that much. Still, this Mobil one is a very good oil.

Review
I usually keep jumping from Mobil to Castrol and just so happened that I 'landed' on this one. This oil kept my Civic engine very clean and running very smoothly. Cold starts is also not a problem. This is one of my options for a 'permanent choice' oil.

What I like
My engine run smooth on this oil, cold starts also no problem