If you thrash it then expect a low return but I have owned one for some 14 years and I average around 30 - 32 MPG. I have had more on a long run but it really depends how heavy your right foot is.

Keeping the cars ignition in good condition will help and reducing the weight you carry, towing etc. But the main factor is driving style.

OLDMINIMAN

26mpg normal town driving. You could push it!
Renew air filter, inflate tyres, set distributor 1mm gap, check timing is accurate, don't race jags or kids on push bikes.
Enjoy!

My first Sportrak after I serviced it and put on some decent tyres,80%road 20% off road would return me about 29/30 mpg. I did not drive it hard and nearly always stuck at 55 - 60mph.
As everyboby said before service and some smooth tread tyres should do the job for you.
Best of luck.
Radarears

dont forget tyres either. if you choose (as i did) to put some gert chunky jobs on, be prepared to lose a few mpg here and there. best way is to just lay off the old right foot.

bravo669 mean and green....
Preg Nato green Sportrak Riviera 1.6 ELXi
235/75/R15 Grizzly Claws.

Fuel consumption varies according to many factors, driving style is the greatest factor, types of conditions can adversely affect consumption, hilly areas, or stop start traffic may will influence MPG.
Servicing the vehicle correctly will be the greatest starting point, incorrectly maintained vehicles can lose up to a third of their comsumption, other factors such as removing any roof racks, roof bars, etc will help consumption figures.
REmove any surplus weight from the vehicle, carrying such things as large tool boxes will affect consumption, drive with the windows up and the sunroof shut can contribute.
Many vehicles get mid 20's, some even more.