You already have a tranny cooler. It's on the lower left corner of your radiator.

I would turn od off on the hilly stretches, but you should be ok on the flats.

Are you sure you're puling 3500 rpms at 70 mph? 4.56 with 35's is very similar to 3.92 with stock tires, so the rpms should be identical.

 

are you positive i have a tranny cooler? I thought they only came with the tow package. As for the rpms, I'm not positive about 3500 but i know its more than 3k. I tried that whole "turn O/D off in daily driving to get better mpgs" and it DIDNT work haha. I lost an mpg doin that. It felt really uncomfortable forcing the truck to stay in those higher rpms for any kind of distance. For the last half tank I started just turning O/D off below 60mph. Above 60 I'd turn it back on and the rpms would go to 2100 (still allowing the tq converter to lockout)

I'm definenty gonna get a weight distribution hitch and brake controller as well as tranny temp guage. Anything else I should do that I'm overlooking?

 

Believe it or not, a cooler does NOT come with the tow package. Because you already have one! Seriously, go look on the bottom passenger side of your radiator. You'll see a cooler. Follow the lines back and it goes right to your tranny. I am on my second dodge ram and I tow all the time. The tow package is a wiring harness, a hitch, and a bigger battery. That's it.

As far od off for mpg, as you found, it only works in the city. No point in lugging the motor with od at 35 mph.

 

thanks rubberfrog, i knew you got my TOTM vote for a reason

 

Glad I could help!

 

I pulled a Mini Cooper on a small trailer today for a 3 hour trip and did just fine. But thats a light load compared to what I have pulled before.