Wow nobody else?
Took it in last week, this was the only thing the SA didn't know if they had found the issue. She said the tech said "different animal" when I told them that the brand new, 2019 GMC Terrain that they gave us as a loaner, had about twice the pickup as our Envision. Of course, the GMC has a nine speed transmission. So I set about to look up the specs. The engines are identical as far as power. Then I thought well maybe the 0-60 would be different because of the transmission. Every spec I've seen lists teh Buick as a tiny bit faster in the QM!! That's with us running premium in the Buick, and regular in the loaner car. So i think for sure, we have something going on. Hopefully when I take it back next week they find something, along with a new axle and fixing the rear AC..