I run full synthetic 10-30 in winter, has anyone any experience with running 5-30 safely in winter? I'm considering going to a lighter weight oil to offset the loss of mileage experienced with this bitter winter.

Any thoughts appreciated.

 

Although I don't have a Q, I am running Mobil1 0W-30 and could say that the car starts pretty easy even after sitting 2-3 days in the -7/0 temperatures that have hit us lately.
I would say it it pretty safe, actually can say safer to run 5W-30 in the bitter winter than 10W-30.