Fuel Economy & Footprint: What Does it Have to do with Mass Reduction?

15th March 2013 by Jay Baron

CAFE standards for model year 2017 have automakers looking towards lightweight materials to help meet automotive fuel economy benchmarks. 

Prior to model year 2011, all manufacturer vehicle fleets needed to meet the same basic fuel economy targets: 27.5 mpg for passenger cars and 23.5 mpg for light trucks.  To meet fuel economy CAFE standards for a particular model year, manufacturers would often offset the sales of less fuel efficient vehicles with smaller fuel efficient vehicles. This has led to the belief that any increase in CAFE requirements would result in the demise of larger vehicles.


Image courtesy of AOL Autos: http://autos.aol.com/article/fuel-economy-standards-survey/


However, what is often overlooked is that starting in model year 2011 each manufacturer’s fleet fuel economy requirement is based on the average vehicle footprint (i.e., track width x wheelbase) for that fleet.  What does that mean?  Essentially, smaller vehicles need to achieve higher fuel economy ratings than their larger cousins to meet the standard.  The figure below provides a snapshot of just a few vehicles of various sizes and how they compare to the CAFE standards established for MY 2017.



As you would expect, the smaller cars do indeed achieve better fuel economy ratings; however, because of the footprint basis for fuel economy those smaller cars must improve just as much as the larger less fuel efficient vehicles.

With the new footprint based fuel economy regulations, automakers will need to find ways to improve fuel efficiency for all vehicles.  For those that promote fuel efficient technologies (such as lightweighting), the future is bright.

More information is available at Center for Automotive Research  or learn about CAR’s Coalition for Automotive Lightweighting Materials (CALM).