2013 model sport.
I have driven this route periodically on I-5 and am familiar. My car has 103k on it, mostly freeway. All fluids are maintained well. During Pandemic I drove once a month but when my other car broke down recently, I drove this instead.
All of a sudden my forward trip of 369 miles only gave me 23.27 mpg! The lowest I ever had was around 26 on a more likely loaded car. I actually ran out of gas - I had to top it off in the middle of the trip. Typically I use Costco gas at both ends.
Return leg of the journey, 382.8 miles, it gave me 29.28 mpg. 27-28 are typical.
I did not do any maintenance in LAX including tire pressure. Only 2 adults with 2 suitcases on both trips.
Forward journey started around 5am so we turned the heater on till about 10am or so (trip is around 6-7hrs including stops). This might be the only difference. I did experience a little vibration at speeds higher than 70mph - on return had wheels balanced. Tires are good too - previous owner used Walmart tire. The trip was during the Thanks giving break and there was a wind/gust warning but we didn’t experience much.
What might have happened?