Should tipping amount depend on car service?

There are luxury cars, standard, and a black car. And I have given the best $20 to my driver when I have visited Houston to standard Uber service.
I booked a luxury car because I wanted to take it,it was my first time and I was excited.
But after the trip, when I was given the driver $15. I sensed he got upset and disappointed with the tip amount.
Maybe he was expecting a little more and the driver was because he was quiet during the entire trip.
In India, no one has a tradition of tipping, the driver just asked the rating and left.
If you ever visit India, no need to pay if you don't want it, it is not a must to pay the tip.
No one will pay anything and just give a five-star rating, and I covered on Uber tipping to my blog.