I use 5W30 full synthetic in my GT - one oil change a year. I add about 1/2 a quart after winter and then change it every July.
I don't like synthetic blends and/or winter oil. The manufacturer makes more money off of this oil than any other, because they can add as much, or in most cases - as little full synthetic stock as they want. Some blended oils have as little as 10% full synthetic. I would go with full synthetic 5W30, or conventional 5W30. As I change my oil only once a year and I have very little burn off 5W30 is the best choice. Temps can go -25C in winter and easily reach 30C+ in the summer.
10W40 will also reduce mileage. 5W30 reduces friction, and a full synthetic 5W30 will reduce it more. This is one of the many reasons why you can drive longer using full synthetic oil. Full synthetic also flows to vital engine components (top end of your engine) quicker in cold weather.
'11 Ram SXT 4x4 quad cab - 5.7L V8; 128,200kms
'09 Malibu 2Lt 3.6L - 140,000kms purchased 1 March 2019
'06 Pontiac G6 GT - 3.5L V6; 162,000kms (rear ended 15 Feb 2019, and given totalled title by insurance)