I bought my winter tires from them. I did a fair bit of research and the consensus is that Walmart winter tires are a good value for the money. Don't expect X-Ice performance and you'll be fine. I ran a set on my '14 and they were awesome. But I'm digressing.....
Walmart wanted me to bring the car back for 100km lug nut check (I did myself but I'm still going to let them do it so they can sign off on it).
While doing the check I did air pressure, natch, trust no one, and of course my tires were severely underinflated.
23, 25, 26, 28. Those were the readings. Explains why poor Shelby could not get past 16.9km/L no matter how hard I tried in my 400km trip. I've bumped the pressure up to 41 PSI, max on the sidewall is 45 so I'm 10% below that.
All that's left now is to visit Walmart for the torque check and to ream them out for the unsafe tire inflation.