I also have an '07 ZX4 with a 5 speed, have topped out at 38 mpg
(6.38L/100km) but usually hang around 34-36mpg (7.14-6.7)thats driving
with cruise on at ~60 (96kmh) speed limit is 65 where I drive, getting
over 65 usually whacks 2-3mpg, and turning on the AC will whack up to
another 6 mpg.

You are correct about the driving style being a huge difference in
the mileage you get.  I was complaining about my ZX4 ses manual to my
favorite mechanice and we went for a drive hooked up to a monitor.

First he drove it (let's just call it) "as recommended" (By
authorities in most countries/municipalities).  Then I told him to
drive like he or I would drive it.

Results: If you drive by a text book 34MPG is indeed the average on
highway. If however your driving has a little more gusto than the
average driver's, expect drastically different results.

Larry, this car indeed fun with stick.  My mileage is well below what
I'd like but I've only myself to blame.

Shelle