I'm due for an oil change and I heard about the GC oil as being thick. I was wondering if it's good to use in the summer on my '07 Taco (6-speed; mileage: 7000Km). I found some GC oil in Canadian Tire and some Maxlife synthetic, and also Penzoil platinum-- $24 for a jug (I think). Any thoughts from the oil gurus here? Thanks.