These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Is that a teacher along as a mechanic for the illegal street aqueduct race?
Danny getting involved in school activities and doing better at his education is just as much of a sacrifice as Sandy slutting herself up and starts smoking for him.
Ho Yay: There is perhaps an undercurrent between Danny and Kenickie. During "Summer Nights" Putzie is seen briefly groping Kenickie who looks like he's thoroughly enjoying it. And "Greased Lightning" is brimming with homo-eroticism what with the butt-shots and Danny's head being in direct line to Kenickie's crotch and vice versa much of the time; the fact that the lyrics are about how much pussy they're going to get makes this a Crowning Moment of Funny. There's quite an undercurrent in the 'Will you be my second?" conversation they have just before the race.
Kenickie's head also likes to find its way in between Danny's knees during the music numbers, A LOT.
Stoic Woobie: Rizzo. Especially in her song "There Are Worse Things I Could Do".
Unfortunate Implications: To mend the rift in the relationship with the boy you like, you have to dress in revealing clothing, wear tarty make-up and talk in a husky voice. Nice.