I second the biking motion, heck if you get a nice road bike you'll probably get to work faster too!
If you absolutely have to drive, get that thing into neutral anytime you can and shut off the engine for a long light. I borrow my Dad's F150 for hauling and it puts truely scary numbers up on the
scangauge, accelerating briskly shows 50L/100km
Going up a hill at highway speed shows 28L/100km, although coasting down the other side shows 2L/100km so it seems to idle efficiently anyways!
I can beat the highway rating towing a trailer or with a load of fence posts in the back quite easily so with a bit of effort you could save some $$.
Ian