Just wondering what key position warms the glow plugs. If I turn my key slightly to the left from the off position the glow plug indicator light comes on. If I turn it all the way to the left I can hear an audible click, and the glow plug light plus a couple other lights come on. Should I only turn the key till just the glow plug indicator comes on, or should I be turning it all the way to left? Also, should I use my GPs in the summer? Thanks