My '07 X500 was close to topping out at around 90 . . . could have been 90 - could have been 85. It was fast enough.
On the occasional interstate trip, even at 70mph, mine has no problem scooting around the big rigs.
Worst freeway mileage was 45mpg on a trip from San Antonio, TX to New Orleans, LA, when I was mostly going 75, and was loaded with clothes and gear for a wedding.
On the back roads where I average 55 to 60, mileage as much as 65mpg.