Gas mileage

I didn't buy an XJ for gas mileage, I bought it for its utility and reliability. I just bought one a few days ago, 01' with 33's and a 4.5in lift, 4.0liter. I do however drive 28miles to work one way and although I now have a very small car payment and I will pay it off fast,i still want to maximize my mpg's. I realize any work I do to increase it probably won't give me much gain but anything is better! Anyways, I love my XJ and any info would be appreciated! Since I purchased the XJ I have changed the oil and tranny fluid to Mobil 1 synthetic. Oil is 10w30 and that's all I have done so far.