Great thread. I always hear anything under 30 minutes is a short trip, but does that count for summer? Or how about multiple short trips, errands, etc?
My drive to the gym is only seven miles, but I’m only at the gym for an hour - in the summer when I get back in my car to go home my temp gauge/engine, never really cools down much - then I drive it back home and I swear that thing is still hot three hours after I shut it off. Last week I did a 20 mile round trip and I was planning on doing a tranny service to my car; I needed the tranny fluid to cool off enough to do a tranny temperature check - it took four hours for that fluid to get down to 112 degrees. Four hours! And then when I started it up it immediately rose in temp. Summer is just different, these cars get to temp quick and stay there.
Winter, I think is where this “short trip” stuff applies, a lot more so than summer. I never see condensation coming from my exhaust in the summer. I never see my temp gauge not get up to range, like I do in the winter. There’s no cold start ups or freezing extreme cool off periods. So I do think summer is different and should be factored into the equation...and yet I don’t think it ever is.