Jim, you'll have the limited slip differential right off the bat with that 2016 6 Speed manual, of course you can always add the LSD differential to any automatic, but unless you can do the installation yourself it does get labor expensive. In 2015 the open differential was a 3.07 ratio and the limited slip equivalent is the 3.09, with the 3.09 being a swap out not requiring any other changes at all. Some of the best online suggestions for more off the line capability are the 3.70 ratio, but that change is also suggesting a torque converter change as well for the maximum combined gains from that ratio, along with a tune change.RY, I did not realize the 6-speed manual RT came standard with posi and the 8-speed auto did not.
How coincidental as I have been looking at a nice used 2016 6-speed.
Another plus for me if I end up getting it.
Most all of us have to decide where are we going to stop putting money into these Challengers as some of these upgrades do force more upgrades to get the most benefit out of them. I just watched a YouTube video of an owner of a 392 Scat Pack removing upgrades he had done, so he could sell the car because he had just bought a Hellcat. Ry