TrailManor Owner's Forum - View Single Post

04-27-2010, 01:33 PM

We recently took our 1997 Suburban 1500 (110,000 miles) and our '08 3326 over the Grapevine into and out of LA to visit Custom RV in Anaheim for annual maintenance.

The Grapevine crosses the mountains north of Los Angeles with 5-6% grades both up and down.

We found that 3rd gear and about 2500 rpms would pull the rig up the steepest grades at not more than 45mph. On the steepest downgrades 3rd gear engine breaking at about the same rpms held the speed to between 55 and 60mph with only light occasional braking.

It's doubtful we could have made the same trip in very hot weather. With the AC off and at the steepest part of the climb our water temp topped out at 210 while 160 is the regular temp. Our Suburban is equipped with the factory towing package and a WDH.

Most posters here with far more knowledge on this subject than us have commented that it's not uncommon for tow vehicles to be underrated for the TM they're pulling. It's one thing to pull in the flat on I-5 and quite something else to go over the Grapevine.

Our 3326 fully loaded for the road weighs 5,000 lbs which is the factory rated maximum for our Suburban. We're grateful to those forum members for helping us properly outfit our rig for a trip like this.

04-27-2010, 01:33 PM	#1
Shandysplace Guest Posts: n/a	A Lesson in Towing Capacity We recently took our 1997 Suburban 1500 (110,000 miles) and our '08 3326 over the Grapevine into and out of LA to visit Custom RV in Anaheim for annual maintenance. The Grapevine crosses the mountains north of Los Angeles with 5-6% grades both up and down. We found that 3rd gear and about 2500 rpms would pull the rig up the steepest grades at not more than 45mph. On the steepest downgrades 3rd gear engine breaking at about the same rpms held the speed to between 55 and 60mph with only light occasional braking. It's doubtful we could have made the same trip in very hot weather. With the AC off and at the steepest part of the climb our water temp topped out at 210 while 160 is the regular temp. Our Suburban is equipped with the factory towing package and a WDH. Most posters here with far more knowledge on this subject than us have commented that it's not uncommon for tow vehicles to be underrated for the TM they're pulling. It's one thing to pull in the flat on I-5 and quite something else to go over the Grapevine. Our 3326 fully loaded for the road weighs 5,000 lbs which is the factory rated maximum for our Suburban. We're grateful to those forum members for helping us properly outfit our rig for a trip like this.