MPG jump after oil change

Got my first oil change done at Toyota dealership. Purchased the SR5P used about 8 months ago from a Subaru dealership. Supposedly they serviced the vehicle with an oil and filter during initial inspection. I put on about 4000 miles and crossed the 36000 mile mark and took it to the local Toy Store for a service. Was averaging 16-18 mpg, now I’m up to 18-19 easily, what oil do you suppose Subaru had put in there, makes me wonder.

 

Probably nothing different. We went from my wife Subaru Crosstrek which took 0W-20 to the 4Runner which takes the same.

 

If you're old enough to remember Car Talk, better mileage after an oil change was one of their puzzlers. According to them, people see improvement because their tires had been underinflated.

 

Judging from some people’s scammy experiences getting oil changes, who knows if MPG improved because this was the vehicles first oil change.

Or it’s just placebo and the apparent increase will wash out within a few hundred miles.

 

it's cause they used Subaru oil the first time. I've always use Toyota in my 2019 runner and mileage is dead on 19.2 no matter how I drive it.
Ok , joking on the first part, but my mileage has always been consistent

 

Snake oil.

 

Maybe they switched to air.

 

"Supposedly they serviced the vehicle.." emphasis on "Supposedly"