Originally Posted by Liredneck
OK the plugs haven't been changed as far as I or the dealer knows . What plugs should I get ? Oem? Aftermarket ?
That's probably why, the Hemi needs new plugs every 30k miles. Go with OEM, people have reported trouble with platinum and iridium plugs (I think it may have something to do with the stock coils), and with 2 plugs per cylinder you really don't need them.
OP, I find that I get better mileage with cruise off because the transmission downshifts much less frequently uphill etc... My dad's 2009 2wd 3.21 Hemi 5 speed has achieved 22MPG on a ~500 mile trip from San Antonio to Oklahoma City. Taking your foot off the pedal on downhills helps too.
Also, if you see that you are coming to a red light just coast to it as much as you can, I don't know why so many people hurry up to get to a red light just so they can stop. All that will do is contribute to poor mileage and premature brake wear. If its been red long enough then it may turn green by the time you get there so you may not even have to stop or at least stop completely. Accelerating from 20 to 60 takes a lot less gas than accelerating from 0 to 60.