Sudden ping spike

Sometimes pinging 1.1.1.1 in cmd shows over 150 ms latency and around 35 ms for 1.0.0.1
Now two questions -

  1. Why do the latencies differ that much for 1.1.1.1 and 1.0.0.1 ? Does this mean i can use 1.0.0.1 as primary dns due to comparatively low ping and use another dns (8.8.8.8 maybe) as secondary ?
  2. While latencies are horrible while checking in cmd,when i go to http://www.whatsmydnsserver.com it show an ip which on pinging shows 13ms ping.I dont understand which result to believe.