2012 Construction SymposiumOmni Dallas HotelAugust 23, 2012

Robert J KrouseGeneral Motors Trailering Engineer

SAE Tow Vehicle Trailer RatingCommittee Chairman

2012 Construction Symposium• What is Trailering?– Just another vehicle spec number?• Torque, Horsepower, Cab-to-axle distance, Brake rotor

size, payload, etc…and Trailer Weight Rating

– Actually everything the vehicle already does…• Launch, accelerate, maneuver, stop, etc—all under

more difficult conditions

– Operator controls the setup– Many different trailer types

2012 Construction Symposium

Just a rating spec?

2012 Construction Symposium• And when we think we’ve found worst case…

2012 Construction Symposium• Rigorous Testing– Powertrain, Thermal, Dynamics & Structure

2012 Construction Symposium• Ratings Comparison

Late 1990s 2012

1/2 Ton Pickup 7,500 10,700

1-Ton Dually 10,000 18,000

1-Ton Dually Gooseneck

13,000 22,800

2012 Construction Symposium• Trailer Weight Rating depends on what you

carry as well as what you can pull

Front Axle Wt Rear Axle Wt

Gross Vehicle Weight

Kingpin Wt

(or Tongue Wt)

Trailer Weight

2012 Construction Symposium• Overload is not good for any tow vehicle

2012 Construction Symposium• Industry Standardization (through SAE)– Specific test trailers and setup– Structural requirements– Launch, acceleration and highway gradeability

(including thermal performance)– Understeer and sway damping– Stopping distance and park brake hold– Vehicle weight considerations

2012 Construction Symposium• SAE Tow Vehicle Trailer Rating Committee

gathered its own handling data

2012 Construction Symposium• Weight Carrying & Weight Distributing Hitches

– Many trucks have higher Trailer Weight Ratings with WD hitch

2012 Construction Symposium• Brake Performance

– Stay out of the ditch (but on top of the cliff)

2012 Construction Symposium• Owner/Operator Role– Heed the ratings– Maintenance (truck and trailer)– Proper setup– Driving style (don’t be in a hurry)– Proper equipment, including…

2012 Construction Symposium• The right truck