A few points. The truck and the Challenger have different transmissions with different gearing. The Ram does have a 3.92 axle ratio; however, the truck's transmission is geared more for fuel economy. The 545RFE has a 5th gear ratio of .67; meanwhile, the W5A580 used in the LX cars such as the Challenger has a 5th gear ratio of .83. So basically to provide a more accurate comparison, the 3.06 axle ratio with that transmission is approximately 3.79 gears with the gearing of a 545RFE transmission so the difference between your truck and the Challenger's transmission is a difference of .13, which isn't a very large difference.

The funny thing is I've noticed since the beginning that the 6.1L is far more fuel efficient than the numbers suggest. In some old Road & Track issues, they were getting better real world results with the SRT LX models than they were with the GM W-body models such as the Grand Prix GXP, Impala SS, Monte Carlo SS in real world results and the SRTs were rated under the older fuel economy standards at 20mpg and the GM models were rated for 27-28mpg, and those W-body models all had Active Fuel Management (same thing as MDS), fuel economy focused gearing, were all lighter and probably more aerodynamic, and had the smaller displacement of 5.3L. The Hemis seem to be quite an impressive engine when it comes to fuel economy when you take into account what they are.

Roswell, that is 1.6 mpg better than the EPA rating is for the city. That is actually quite impressive. Those 3.5Ls are efficient engines. I have been able to get over 30 mpg many times with my Intrepids.

I have found those computers to be off. Chrysler ones seem to be close. The one in my father's Taurus is way off and not in the direction one would prefer it to be, and considering how low the numbers are on there, that isn't encouraging.

I try to keep my tank above the half way mark so then I don't develop a bad habit of not paying attention and running out. My father has the bad habit of running out. He did that on the way home on the night AFTER I was born. Fortunately, the only people with him were my brother and my Grandmother. He has ran out of gas several other times, but that was the most memorable one, especially since my Grandmother has it in her achieves of the stories she has written in the newspaper. It was quite an amusing story in what she wrote and the parts that I knew she probably had to cut out (the part where he kicked the car saying "oh what's wrong now with this stupid thing." and it getting progressively more colorful afterwards). He unfortunately hasn't learned since I had to fill up the extra vehicle yesterday he drives sometimes and it took more gas to fill it up than what my brother said it had for its capacity and he drove it for six years straight.