Demand is growing in Canada for vehicles with all-wheel drive (AWD). These two technical reports look at how AWD systems work, and whether they affect vehicle weight, fuel use and emissions.
All-Wheel Drive Component Analysis (May 31, 2016)
This report analyzes AWD systems on the market with a view to improving weight and fuel efficiency. It compares the pros and cons of different systems and vehicles. The report also discusses changes that could be made in design, materials and manufacturing to increase efficiency.
The report studies:
- how AWD systems are structured and how they operate
- ways to improve fuel efficiency such as using AWD disconnect systems
- which models of AWD vehicles have extra mass and higher fuel use
- trends in AWD technology
- changes that could increase efficiency
- the teardown of three popular AWD vehicles
- the cost of AWD disconnect systems
Request a full report by contacting the ecoTECHNOLOGY for Vehicles Program at Transport Canada.
Tailpipe Emissions and Fuel Economy for 2-Wheel Drive Vehicles and All-Wheel Drive Vehicles Tested on a Double-Axle Chassis Dynamometer: A Comparative Study (October 17, 2016)
This study compares the emissions and fuel use of a group of all-wheel drive (AWD) and two-wheel drive vehicles.
Three pairs of vehicles were tested at Environment and Climate Change Canada in Ottawa. Each pair was the same vehicle model except one was AWD and the other was front-wheel drive (FWD). They were tested for tailpipe emissions, fuel use, and wheel torque.
The study found that:
- the amount of AWD use depended heavily on driver behavior and the design of the vehicle’s AWD
- AWD use caused extra fuel use but a bigger cause was the added weight of the AWD parts
- only one in three vehicles used their AWD more in a cold temperature (-7C)
- fuel use increased overall in colder temperature
- AWD vehicles showed no differences from FWD vehicles in emitting CO, NOx, and THC gases
Authors: Aaron J. Conde, Martha Christenson, Brad Richard
Purchase the full report on the Society for Automotive Engineers website.