I have an 04 tb I6. I was getting maybe 210 miles to a tank of gas. I cleaned the throttle body and the filter ( k&n) and it made some difference. However after so good old research I found that if you change your map sensor and the VVT or even clean the VVT ( variable valve timing ) this helps a lot. since the change I am seeing a tank of gas lasting way more like stock and that was more like 295 - 320 city. highway like 400 to 420..
i also live in Florida where the temps are 90 to 100 summer and like 75 to 85 winter I failed to say the truck has 108.500 on the motor and trans and drives like a champ.
hope that helps.
New to the forum. My wife and I just bought our first TB. It's a 04' LS with the I6 and it has about 64k. We are getting terrible mileage and I've read most of the gas mileage related posts. I'm still somewhat confused as to why I'm getting only 14-15mpg when I drive 70%+ highway miles. I have size 14 shoes, but I'm only a 72-80mph driver on the highway. Any advice will be greatly appreciated.