I have to assume because it only meets the minimum HTHS. I also noticed the asterik on the GM6094M approval "meets performance". So is not really independently approval tested by GM.
Their 10W-30 is a THICK GF 30-weight - it has almost the same specs as Valvoline Maxlife 10W-30!
I'll concur that GTX isn't 'the best' winter oil out there - I've got what I'm guessing is bulk API SM/GF-4 5W-30 in my car right now, and cold starts are noticeable harder than the PC dino I had in before.
Originally Posted By: addyguy
Their 10W-30 is a THICK GF 30-weight - it has almost the same specs as Valvoline Maxlife 10W-30!
I'll concur that GTX isn't 'the best' winter oil out there - I've got what I'm guessing is bulk API SM/GF-4 5W-30 in my car right now, and cold starts are noticeable harder than the PC dino I had in before.
The way I see it GTX 5W-20 looks like a good 5W-30 winter oil. It's the thickest 5W-20 100°C cSt I've seen with a very low pour point.