Other than being a light foot around town, Does anyone have any good ideas/experience with increasing fuel economy and possibly horsepower in my '04 XC90 2.5T?

 

properly inflated tires, put it in N at stop lights if your waiting for somebody to come out and get into your car etc leave it running takes more gas to start and stop it. K&N air filter. I seem to get better mpg's with 93. other then that keep your car in good condition change the oil, tune it up. stay on top of maintance