Ok so I’m not sure what is up with my car i know my radiator isn’t the best but still it keeps my car really cool for the most part but whenever i full fill up my gas tank my car will start running warmer than it normally would but then if i have a passenger it doesn’t do that I really confused and i was wondering if anyone had any insight

 

Is it actually running warmer, or just the needle?
First I'd check all my ground connections, they can play havoc in odd parts.

I'm sure others would chime in too!

 

i've noticed that too, i think its the ground for the gauges, its really the only explaination

 

I honestly haven’t really played around with it since it’s still in the safe area I was just wondering what everyone thought was happening and yeah it’s just the needle that shows me but I have no other temp gauge to check so it probably is a ground