Hello everyone. My wife brought home her new 2015 Chevy Malibu 2.5 4 cylinder tonight and I've jus read the manual. It says 5w-20 is recommended and 0w-20 is also suitable. BUT if temps get down to -20f to use 0w-30 for "easier cold starting for the engine at extremely low temperatures". Now we live in wisconsin and we did have a few days it was -20 to -25 roughly but I won't be dumping the factory fill for awhile. My question being wouldn't the 0w-20 provide easier starting too or even better than the 0w-30? So why recommend a 0w-30 weight over a 0w-20 weight when it's very cold when the 20 weight is recommended and IMO would flow better? Just seems odd or am i missing something?