1 ton dually or Medium Duty for large 5er?
We're looking at large 5ers and these things are HEAVY. I know a 1 ton dually diesel will get them moving down the road and that's not what I'm worried about. I'm worried about getting the rig stopp...
Forum Discussion
I do NOT pull a 30K trailer, AT 30K lbs total, I can pull a 30% grade in 1st gear.
I would not JUST look at the gcwr of the truck. Bigger trucks get drive train speced based on the end user. If a chassis is designed to tow a trailer doing over the road work, it will have a higher HP and taller gears, with a minimum of 15% gradability, IE the steepest grade it can pull then it literally stalls out!
If the chassis is to be used as a typical city box van, it might be geared in top gear to literally be turning at best mpg rpm for the motor at 55 vs 60-62 for an otr setup. A local rig may have low enough gears to pull grades in the 30-40% range at its gvwr/gcwr that it is designed to be run at.
A dump or cement mixer truck, will have lower hps, but a high torque motor, setup to go 55, but have the ability to do off road work with gradability;s into the 50-80% range! along with many gears to choose from say 15-20. An otr rig doing the same gvwr total, may only have 6-8 gears! so a lot less ability in some cases.
Then the sales rep and the person buying, may also spec a higher HP if the rig has lots of wind resistance, like say a car/cattle hauler may need upwards of 30-35% more hp to overcome the wind resistance vs say a typical 18wheeler. Meanwhile, a rig with a full aero pkg, may need 30% LESS hp to move the same loads! ALL of these items go into what a class 6-8 rig will have in the form of a drive train. There is no one size fits all BS as there is in light duty trucks, ie DOT class 3/1ton and smaller rigs. Even the class 4 and 5 rigs have typical LDT engin axel ratio gcwr's, which if you look at the new SAE specs, really mean nothing, max grade to pull in 1st gear is 12%. My drive way is steeper than that! The road my sister lives on is 18%! I'd get to here house, hit the dead end at the bottom of the hill, and not make it back to the top!
I've rattle off a lot of things, many on here say is bogus, not needed etc info. because it relates to other types of useage, not RV useage. But reality is, if you are pulling, hauling etc, not matter the trailer, ALL of the above will effect how well you enjoy the rig or not! It is not fun sitting on the bottom of a hill blowing up a $3K tranny at 12K lbs, when it is rated to 16K gcwr! yep, been there done that! Hence why I have an mdt setup as I do!
Marty
I would not JUST look at the gcwr of the truck. Bigger trucks get drive train speced based on the end user. If a chassis is designed to tow a trailer doing over the road work, it will have a higher HP and taller gears, with a minimum of 15% gradability, IE the steepest grade it can pull then it literally stalls out!
If the chassis is to be used as a typical city box van, it might be geared in top gear to literally be turning at best mpg rpm for the motor at 55 vs 60-62 for an otr setup. A local rig may have low enough gears to pull grades in the 30-40% range at its gvwr/gcwr that it is designed to be run at.
A dump or cement mixer truck, will have lower hps, but a high torque motor, setup to go 55, but have the ability to do off road work with gradability;s into the 50-80% range! along with many gears to choose from say 15-20. An otr rig doing the same gvwr total, may only have 6-8 gears! so a lot less ability in some cases.
Then the sales rep and the person buying, may also spec a higher HP if the rig has lots of wind resistance, like say a car/cattle hauler may need upwards of 30-35% more hp to overcome the wind resistance vs say a typical 18wheeler. Meanwhile, a rig with a full aero pkg, may need 30% LESS hp to move the same loads! ALL of these items go into what a class 6-8 rig will have in the form of a drive train. There is no one size fits all BS as there is in light duty trucks, ie DOT class 3/1ton and smaller rigs. Even the class 4 and 5 rigs have typical LDT engin axel ratio gcwr's, which if you look at the new SAE specs, really mean nothing, max grade to pull in 1st gear is 12%. My drive way is steeper than that! The road my sister lives on is 18%! I'd get to here house, hit the dead end at the bottom of the hill, and not make it back to the top!
I've rattle off a lot of things, many on here say is bogus, not needed etc info. because it relates to other types of useage, not RV useage. But reality is, if you are pulling, hauling etc, not matter the trailer, ALL of the above will effect how well you enjoy the rig or not! It is not fun sitting on the bottom of a hill blowing up a $3K tranny at 12K lbs, when it is rated to 16K gcwr! yep, been there done that! Hence why I have an mdt setup as I do!
Marty
