Fuel efficiency: Unexpected differences (comparing each half of a round trip)

[7milesout]

I'm sure many rental/lease vehicles are slightly abused, too.

Slightly? Have you ever rented a car? When I do, one or the other pedal is to the floor. Not every tire is in contact with the ground at all times. A rental car is where I learned how to do a proper neutral drop.

I rented a G4 CVT turd from Turo one time on vacation, just for fun. I've never had a throttle planted to a floor more in any vehicle. I took it to Death Valley and still hammered it everywhere. It started having some kind of problem in Death Valley. I can't remember exactly. But in the hottest part of death valley, full max A/C, me giving it hell, I want to say, it started making some kind of weird smell that was blowing into the cabin. And it was just barely keep the inside of the car cool. I decided that since I was in Death Valley, in the middle of no friggin where, in August and noone around, maybe I should take it more easy on the car ... just in case. I did, but the weird smell didn't go away until we got out of Death Valley. I think something under the hood might have been burning.

So, abused? Yeah, they get the crap beat out of them.