[BluMtn]

I have a 30' toyhauler I pull with my 13 crewmax. I have the factory supercharger and hills are not an issue, both up and down. I let the engine do the work both ways. I pull a lot of 7% grades in warm weather and have not had any issues yet. My only problem is finding gas stations close enough together to get where I am going.

 

[RinconVTR]

Just pulled my 32' 7k TT thru the Rockies a couple weeks ago. I was 1st gear up and down (20-25mph) from 8000-12000ft, not due to power (there was always more then enough of that) but for comfort and control. You need full concentration and slow speed or the odds of something real bad get real high, literally. I used pull outs as soon as there were cars behind me. No problem.

After the fact, I found another app posted on here for Toyota specific items that WORKS flawlessly. Cost's $4 for the app and $10 for the extra PID's, but its way worth it. Its called ODB Fusion.

 

[TXsurfer]

I have a 30' toyhauler I pull with my 13 crewmax. I have the factory supercharger and hills are not an issue, both up and down. I let the engine do the work both ways. I pull a lot of 7% grades in warm weather and have not had any issues yet. My only problem is finding gas stations close enough together to get where I am going.

I put the 46 gal transfer flow replacement tank in mine - awesome