I have a new ’06 Pathfinder with 2500 miles on it now. It’s about 2 months old.
I live at a very high altitude (11,200 feet) and 99.9 percent of my driving is done on the highway, over mountain passes. Using regular gas, a 100 mile trip from Denver to my house gives me a little better than 20 mpg. Pretty good for a 4700 lb car and a 6000 foot elevation gain.
Yesterday, on a trip back from Denver, I mistakenly put premium in it. I got just under 17 mpg.
The cars ‘specs’ call out ‘For best performance, use premium gas.’
That seemed a little odd. My understanding is that at altitude, premium does nothing for you. It appears though, it actually does worse. Is that a correct assumption?
Perhaps the premium squeaked out another horse power or two, but I sure couldn’t tell the difference, and the mileage difference is pretty significant. It’s much worse with premium.
Side note: I don’t plan on burning anything but regular in the car. I just screwed up and put premium in it. [sub]Damn gas stations [even at the same type] sometimes the premium is on the left, sometimes its on the right[/sub]