What weight motor oil do you guys run ?

[turbotaone]

My owners manual says to use10w30 in my TTA,
but I was wondering if I could go a little heavier
since I only drive the car in hot weather. Right now
I'm using Mobil1 full synthetic 10w30. I would like
to know what you guys are running in your TTA's ?

Thanks James

 

[1987 GN]

Mobil 1 10W30 in my TTA.

 

[Lee_Burough]

Winter: 5-30
Summer: 10-30

Gm engineers have reasons to recommend what they do, I trust their advice.