Tip if your passenger rating is low. 

Just like you can rate your driver after a ride, the drivers can also rate passengers after a ride.  Most people don't even know their own passenger rating.  You're unable to view your Lyft rating, but in the Uber app, you can view it by tapping the menu in the top left corner of the app. 

We drivers use the passenger rating as a kind of unspoken way to communicate to each other who might be a good passenger and who might be a bad passenger. 

We interpret passenger ratings a little bit different than your normal 1-to-5-star rating.  A 5.0 is a perfect rating, but likely means it's just a new rider.  Something in the 4.90-4.99 rating means they're a great passenger with lots of past rides.  A 4.80 means they're OK.  A 4.70 means they're "eh," but decent and probably received a 1-star rating somehow (what did they do?).  A 4.60 is a really bad rating.  And a 4.50 means you are somehow an absolutely awful passenger and might get kicked off of the platform.  I have never seen below a 4.50. 

One day, I got a request from a passenger rated 4.55.  I took the ride out of boredom and curiosity — I just had to see how this person had a rating of 4.55. 

I immediately regretted my decision as the guy got in.  He was sweating profusely, and he acted drunk, despite it being only 3 p.m. He reeked of a horrid smell that was somehow a mix of cabbage and old cheese.  He pulled out a vape pen and asked if he could smoke it.  After I told him I would prefer if he didn't, he then asked me if I voted for Donald Trump or Hillary Clinton.  I told him I don't discuss politics with passengers.  Then he tapped on my shoulder and asked if I was a pepperoni pizza or pineapple pizza kind of guy.  I said pepperoni, and to please not touch me again.  He then proceeded to tap on my window while simultaneously humming in the most annoying fashion over the next few miles, and then he slammed my door when he got out.  There was a sweat stain on my seat.  Wow. 

I contributed a 1-star rating to his already low rating and brought out the cleaner spray. 

Most riders get 5 stars from me.  I rarely hand out bad ratings.  You have to be a really bad passenger to get a bad rating. 

Tips change all of this.  Anyone who hands me cash at the start of a trip is getting a guaranteed 5-star rating.  Anyone who shows me them physically entering a tip on the app at the end of the ride is also getting a guaranteed 5-star rating. 

If it's late at night, or you're leaving a very busy event, I'm sure you want to get home quickly.  Drivers tend to be very selective with passenger ratings late at night or at big events, as they want to get the best passenger possible — a low rating can possibly mean you're likely to vomit in their car.  I personally will not accept a request from a passenger who has less than a 4.75 rating late at night, and to date, I have never (knock on wood) had a person get sick in my car. 

If your rating is low, it will probably take a while for you to be matched with a driver. 

Tipping can get your rating up, and get you better and faster rides.