The EPA indicates that in general, have the correct mfgr recommended tire pressure will improve MPG by 3.3%. Conversely, MPG is decreased by 0.6% for every pound that the tires are below recommended pressure.

This is a good tip. Another few things to keep in mind:

- Check your engine air filter to be sure that it's clean and your engine can breathe freely.
- Try to find a gas station with a less that 10% ethanol blend. I've found the 10% blend really messes up your mileage (I lose about 10 to 15% of my MPG when running that garbage).
- Keep unnecessary weight out of your car. I keep my Santa Fe empty; only the stuff I need and when I load things in, they only stay as long as necessary.
- If you carry loads on the roof, only do so as long as necessary; remove them when you're done as drag = reduced MPG.
- To echo what was said above, keep your tires checked. I'm a bit OCD about this now as about two years ago, a friend noticed one of my tires was a little low. When I checked it, the pressure was a mere 15 pounds! You couldn't even tell from the outside!!! I'm fastidious about it now.

This is what I know...do with it what you wish. :beer: