I'm thinking about a new truck (possibly).

I noticed there is an option of an 8 speed automatic or a 6 speed automatic.

Other than the 2 extra miles per gallon, what is the big difference here?

What are the advantages of one vs the other?

 

I've had the 5-speed in a 2010 Dakota (very close cousin to the 6-speed) and now have the 8-speed in my 2013 Ram.

The 8-speed is a very different animal compared to the 6-speed. In short, it behaves differently, but is a smoother transmission, in my opinion, especially at the higher (numerically) gears. It also is a "peppier" transmission than the 6-speed. A Ram with 3.21 axle gears and the 8-speed feels almost as good as a 3.92 axle geared 6-speed, judging from my test drives. One of the reasons is because of the two extra tranny gears, they can put better ratios in the transmission.

I settled on the 3.55 axle gear ratio with my 2013 Ram, partially because of the 8-speed being better with all gear ratios.

In conclusion, the 8-speed gets a little better gas mileage, and has more pep. However, you have to step up to a 2013 model year (first year they offered it as an option) or newer truck to get the 8-speed. Not sure if you were looking at new or used trucks. In addition, the 8-speed became more easily available in 2014 with many trim levels, where in 2013 it was just an option, so it is a little harder to find 2013s with it.

 

Thanks, I'm kind of thinking about taking advantage of the buy back program and looking at some 2015's.

 

Ah, OK. Well, you'll have plenty of options then. The 8-speed will be widely available, and while it will cost a little more, I'd highly recommend it.