lms1943 Report post Posted March 1, 2012 We are new to class A motorhomes (2001 XC360 Airstream with a 300Cat/Allison. Peviously we had a 30' Airstream TT and a 2011 Dodge deisel, and had no problems with a 10-12 % grades. We are flat towing a Mini Cooper (weight 2400#). My question is what can I expect with the motorhome in the mountains. Thank You Share this post Link to post Share on other sites
wolfe10 Report post Posted March 1, 2012 In a word (actually two words): NO PROBLEM. Your Caterpillar 3126 has 860 lb-ft toque at 1,440 RPM. With the six speeds you Allison 3000 series transmission has, no problem. You might want to read the Allison "Mode Button" in the FMCA e-newsletter that came out today as well as use of the transmission and exhaust brake in descending those grades. Here is a discussion of mountain driving: http://community.fmca.com/topic/225-mountain-driving/page__hl__grade__fromsearch__1 Brett Share this post Link to post Share on other sites
danddferr Report post Posted March 10, 2012 I have a 32ba Open Road Allegro towing a Honda Fit. It is a Fred ( front end diesel ) and I had no issues with 9 % grades last summer. Except for the fingernail indentations on the copilots seat! Take your time and read up about climbing hills. If third gear is what you needed to climb the hill then put it in third and let the engine brake do it's job going down. Use the service brakes as needed to decrease speed. Dan Share this post Link to post Share on other sites
TombstoneJim Report post Posted March 11, 2012 I have a 35footer with a Cat 3126. I normally tow a Jeep wrangler 3000lb. I don't think I have ever been on a hill that I could not exceed the speed limit if I wanted to waste the fuel. Share this post Link to post Share on other sites
wolfe10 Report post Posted March 11, 2012 Jim, In a word (actually two words): YOU WILL! Perhaps not on a 4-5% grade but on sustained 6% and higher you and other heavy vehicles (truck, gas coaches, diesel coaches-- everyone) can not. Having a Caterpillar, you may have already read the excellent "Understanding Coach (RV) Performance" on the Cat RV Club Website: http://www.catrvclub.org/forum/index.php. Look at the page that shows HP at the rear wheels need for coaches of various weights to climb a sustained 6% grade. You won't find ANY coach doing that at 70 MPH. Share this post Link to post Share on other sites
Greatlakediver Report post Posted March 15, 2012 Brett, Great article on the Allison transmission mode button and clarifying how to use the enconomy mode. Jeff Share this post Link to post Share on other sites
wolfe10 Report post Posted March 15, 2012 Jeff, You are welcome. Brett Share this post Link to post Share on other sites
