It happens some times that I don't drive my truck for few days. Should I add anything to the fuel? If yes, what do you use? I don't use any additives currently.
Thanks

A few days is no problem but if you go say a month or more between fill up then I would add a stablizer.

Any names or brands? I never use one and this is my first diesel truck.

...sort of a contronversial topic.

Stanadyne Performance Formula will do the job and it's GM approved as far as being the permissible type of fuel additive.

Grab your preferred beverage and do a search on additives... lots of reading...plenty of opinions too.