Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - quest for better fuel mileage while pulling a travel trailer

slowmover · 03-15-2010, 11:37 PM

Tractor-Trailer Drag Distribution

25-35% Tractor Drag

An aerodynamic tractor only affects the flow over the trailer face!
70% of the drag of a tractor trailer is trailer drag.

65-75% Trailer Drag

- 30% Trailer Front Face
- 30% Trailer Base
- 30% Undercarriage
- 10% Side and Top Surfaces

Trailer Drag

Pressure Drag - normal to surface

• Hot Spots: front face, rear face, undercarriage
• Comprises more than 90% of total trailer drag

Friction Drag - tangential to surface

• Hot Spots: side and top surfaces
• Comprises less than 8% of total trailer drag

Roughness Drag - this is a pressure drag increment

• Hot Spots: side and top surfaces
• Comprises less than 2% of total trailer drag

Getting Better Fuel Mileage - Truckers' Trucking Forum | Largest CDL Truck Driver Message Board

(.pdf 5.8 Mb) PETERBILT WHITE PAPER ON AERODYNAMICS

Aerodynamics 101

According to Peterbilt Engineering Systems Manager Rick Mihelic, the truck engine must overcome five primary forces in order to move the truck down the road. They are:

• Rolling resistance, or the loss due to friction between the tires and the road;

• Mechanical losses, which result from friction inside the engine and the drivetrain;

• Accessory losses, which result from running alternators, air conditioners, fans, etc.;

• Grades, or changes in road elevation; and

• Aerodynamic drag.

http://www.peterbilt.com/eco/pdf/Aer...%20PAPER-2.pdf

(.pdf 3.2 Mb) KENWORTH WHITE PAPER ON FUEL ECONOMY

http://www.loadtrek.net/loadtrek_net...whitepaper.pdf

(ARTICLE) HEAVY DUTY TRUCKING

Hands-On Tips For Buying Fuel, Driving & Spec'ing For Better Economy

Tips For Drivers

Tips For Drivers

***** In a major study, The Technology and Maintenance Council of the American Trucking Assns. identified the major factors that most affect fuel economy. The top 10 are:
*****
1: Driver skills, then,

***** 2: Speed - especially with poor aerodynamics
***** 3: Cooling fan "on" time
***** 4: Electronic versus mechanical engines
***** 5: Using rib tires in every wheel position
***** 6: Cutting idling time
***** 7: Using single semi-trailers instead of doubles
***** 8: Using a roof fairing rather than a flat roof
***** 9: Using a roof fairing rather than a raised-roof sleeper
***** 10: Slowing down 5 mph

.

03-15-2010, 11:37 PM	#12 (permalink)
slowmover Banned Join Date: Oct 2009 Location: Fort Worth, Texas Posts: 2,442 2004 CTD - '04 DODGE RAM 2500 SLT Team Cummins 90 day: 19.36 mpg (US) Thanks: 1,422 Thanked 737 Times in 557 Posts	Tractor-Trailer Drag Distribution 25-35% Tractor Drag An aerodynamic tractor only affects the flow over the trailer face! 70% of the drag of a tractor trailer is trailer drag. 65-75% Trailer Drag - 30% Trailer Front Face - 30% Trailer Base - 30% Undercarriage - 10% Side and Top Surfaces Trailer Drag Pressure Drag - normal to surface • Hot Spots: front face, rear face, undercarriage • Comprises more than 90% of total trailer drag Friction Drag - tangential to surface • Hot Spots: side and top surfaces • Comprises less than 8% of total trailer drag Roughness Drag - this is a pressure drag increment • Hot Spots: side and top surfaces • Comprises less than 2% of total trailer drag Getting Better Fuel Mileage - Truckers' Trucking Forum \| Largest CDL Truck Driver Message Board (.pdf 5.8 Mb) PETERBILT WHITE PAPER ON AERODYNAMICS Aerodynamics 101 According to Peterbilt Engineering Systems Manager Rick Mihelic, the truck engine must overcome five primary forces in order to move the truck down the road. They are: • Rolling resistance, or the loss due to friction between the tires and the road; • Mechanical losses, which result from friction inside the engine and the drivetrain; • Accessory losses, which result from running alternators, air conditioners, fans, etc.; • Grades, or changes in road elevation; and • Aerodynamic drag. http://www.peterbilt.com/eco/pdf/Aer...%20PAPER-2.pdf (.pdf 3.2 Mb) KENWORTH WHITE PAPER ON FUEL ECONOMY http://www.loadtrek.net/loadtrek_net...whitepaper.pdf (ARTICLE) HEAVY DUTY TRUCKING *Hands-On Tips For Buying Fuel, Driving & Spec'ing For Better Economy* Tips For Drivers Tips For Drivers *** In a major study, The Technology and Maintenance Council of the American Trucking Assns. identified the major factors that most affect fuel economy. The top 10 are: * 1: Driver skills, then, * 2: Speed - especially with poor aerodynamics * 3: Cooling fan "on" time * 4: Electronic versus mechanical engines * 5: Using rib tires in every wheel position * 6: Cutting idling time * 7: Using single semi-trailers instead of doubles * 8: Using a roof fairing rather than a flat roof * 9: Using a roof fairing rather than a raised-roof sleeper * 10: Slowing down 5 mph** .