My mileage didn't seem to change. 16.5 avg. mpg? Wow! I've never had anything under 20 mpg. even though I have a lead foot. If I were you I'd go back to the stealer and ask questions.
True, but a drop of 4mpg is pretty significant. Perhaps a check of rpms at different speeds with another RAV to see if that's causing it.If mine changed, I haven't noticed. But even if it did, I'd rather it use a little more gas than listen to that annoying whine!