You got understand !!

Back in the late 90's early 2000's fuel price wasn't a issue as today so automakers didn't had MPG as a priority.

Actually if you check vehicules made from 1999/2002 the trend was similar.

Toyota 4runner 6 cylinders,nissan pathfinder V6,ford explorer V6,chevy blazer etc was all giving almost the same average mileage.