If you dont have a turbo or autocross in summer weather probly no need for a 50 weight.( but they are pretty stable if you do a lot of milage hard driving between changes)
I recommend a MOBIL1 0w-40 or SynPower 5w-40 for winter.If in your CA location it never gets cold you cna keep in teh 50 weight, if it ever gets close to freezing tho consider the above recommendations.
Fred...
