ORIGINAL: pestep
Of course, if you intend to keep the car for 30 years, the lifetime powertrain warranty you get with the R/T is even more valuable.
First of all, welcome to the site pestep. Not necessarily, the thing you have to remember is that the lifetime powertrain warrantee is limited to just the powertrain and would be very easy to void. Chances are you would have to have the dealer do all of the services instead of any DIY (do it yourself) which will be charged at a premium. I admit I'm not an expert at warrantees, but I'm sure most of the things you would have to repair the warrantee would not even cover (gaskets, sensors, and the such). It would probably just cover the engine itself if it was blown. Considering how I plan to take care of it, this will probably not be a very big issue.
Besides the value of the Challenger itself with a 6.1L as opposed to the 5.7L will probably be the value difference between a 426 Hemi powered Challenger as opposed to the 440. The 426 is still worth a whole lot more because it is more sought after due to the legendary reputation and it is more rare despite the fact that the 440 is really a more practical choice with ever so slightly less power. It will even itself out and then some.
Remember guys that the fuel economy might be different with the manual. Generally, manual versions get better fuel efficiency thanks to the fact that they are more efficient in the power transfer. It also could be improved depending on what gears are used in the Tremec. If the combined top gear ratio is taller in the manual version than the combined top gear ratio in the automatic, that will help remedy the problem. The short gearing that the LX car's 6.1L models feature deserves a lot of the blame for the lower fuel efficiency, as well as the inefficiency in that MB designed 5-speed auto.