Yeah that's a Kenworth truck. This was actually made more rusty for a disastrous Malayalam movie, Overtake, a part ripoff of Speilberg's Duel. This one was actually owned by KSEB and used during some dam construction. They auctioned it 2-3 years back and bought by the movie team. It's actually a low flat bed trailer. The tanker body is made for the movie. Don't know the curent condition, was of course a collectors piece.
I saw this big guy on the way to Kanyakumari once! We entered the highway and at an intersection, the truck was there. I couldn't figure out if it was a Kenworth or a Mack or a Freightliner. Glad I saw this today and got to know what it actually was!