Hello all, I'm new to this forum and found the information provided here to be of extreme value. I recently purchased a 3 yr off lease 2003 LS430 (Platinum Blue Pearl), with 53,132 miles, and find that I have fallen head over heals in love with it. For the first 3 or so weeks my MPG was phenomenal in that I was getting roughly 19.2 MPG city & hwy. I have since done the 55,000 service at which time I changed the oil with mobil1 7500 sync blend 5w-30, (Lexus/Toyota dealer says they use only Synthetic Blend in the LS) Toyota oil filter, and K&N air filter. Since then my MPG has dropped to 16 to 17.3 MPG. I first attributed it to the K&N and consequently purchased a paper filter from NAPA which is reportedly as good a quality as the Toyota/Lexus filter, but still my MPG remains poor. Is it the oil, or is there something I'm missing? I also use Chevron 92 octane.

Thanks for your input.