Is there anything safe you can add to your oil to increase viscosity?

My dealership gave me free lifetime oil changes, and free lifetime warranty. I did my own first oil change at 1000 miles and put 5w-30 in it.

I live where it's really hot and just don't trust that thin oil when it's over 100F outside.

My thought was maybe I could just put some lucas or something in after they change it each time.

I want to let them do the free services so I have a good service documentation if I would ever need to make a claim on that "lifetime warranty"

 

personally i'd stick with the dealership supplied oil changes that correspond with your vehicles warranty as opposed to dumping an additive that will almost certainly void your warranty should a situation ever arrive.