I had a 1999 Nissan Maxima before this vehicle, and yes it still saves
fuel at 80 mph, it averages about 32 mpg at this speed. I am bitter
because this car has been in the shop for about a third of the time I
have owned it, and now they refuse to do anything about the humming
noise. Fresh off the lot the engine light would come on if you punched
the gas and accelerated to interstate speeds. They took a while to
figure out the problem, and then loaded a software update to the
computer that fixed the issue. They did make one attempt to fix this
humming noise, they actually replaced the transmission. However, when
that repair didn't fix the problem they decided they weren't obligated
to repair it due to the speed limit.