I have driven from minnesota to oregon in my 97 GT.
cruise control at 70mph.
only time I stopped was for gas, food, or bathroom. and I usually was able to take care of all 3 in one stop, so 99% cruise control highway.
and I did not get the 540 people are talking about.
it was right around 450 using 16 gallons(which is still good a little above 28mpg).
if you use all 17 gallons, then you get what is coming to you.... lol.
anyway, I suppose it could vary vs a GTP due to the gearing difference.
but I still can't see 36 mpg as being a reality.
and a smaller motor does not mean better gas mileage, especially vs bigger motor in same car.
I did that same trip in a honda civic, and managed 36 mpg. not THAT much better considering the motor size difference! (it WOULD add up in the long run though). (the city mpg was the biggest difference)
our 4runner has a V6, they also made them with a 4 cylinder
and I hear people talk about the "mpg". well, maybe it is slightly better under certain conditions, but towing? Passing? steep hills? (Why would you buy a mid sized SUV with a 4cylinder???)