Just performed timing belt change and adjusted the valves on the above (101k miles). Prior to the service, I would average about 27 MPG highway and 21.2 around town according to the trip computer. I've compared this to actual calculated mileage numerous times, and it is within about .1-.2 mpg.
Now that I've taken a few of the round trips that I normally do (about
250 mi. each way) I have some comparative information.....on my last trip, mileage was 29.6 mpg highway (average speed 63.4 mph....I am certainly not a 65mph guy), and I've ranged 29-29.5 over the last 3 runs. Around town I've been getting around 22.4.
Overall, not too shabby for a couple of mornings of work.......I'm sure the improvement has everything to do with the valve adjustment. The belt/water pump/etc. would have little to do with it (unless there was a bad bearing somewhere that wasn't "whining").
Just an FYI....