Viewpoint: Stephen Remondi

Exa Corporation's president and chief executive says simulation-driven design empowers OEMs to develop beautiful, efficient cars – digitally

The way cars are designed and engineered is changing rapidly to meet the challenges of emissions regulations and consumer expectations for fuel efficiency. 

There has been a great deal of media coverage on how the regulated fuel economy ratings for cars are becoming irrelevant predictors of results in the real world. As regulations on CO2 or fuel economy get tougher, the gap between the reported numbers and actual consumer experience increases. Regulators and consumers alike think they are achieving better results than they are. Recent studies indicate that the gap between sticker and actual performance is 30% on average. 

Regulatory agencies are responding. Part of the problem is how cars are tested. Clearly a standard test has to be established so that comparisons between vehicles can be made. In Europe, CO2 emissions are measured under the New European Drive Cycle (NEDC) test procedure. This drive cycle was developed more than 30 years ago and no longer reflects driving behaviours. 

Authorities are looking at introducing updated emissions testing methods as early as 2017, laid out under the Worldwide Harmonised Light Vehicles Test Procedures (WLTP) proposals. The WLTP test cycle will evaluate CO2 emissions under a more realistic and modern driving cycle. This will help to close the gap between reported and actual fuel economy and emissions, though it will not eliminate it.  

As a result of WLTP, we can expect to see significant changes in vehicle designs. The WLTP test cycle will subject vehicles to higher operating speeds and for a longer sustained time – raising the importance of aerodynamics. But significantly less time will be spent at idle than in the NEDC test, making the regulatory benefit of start-stop solutions less important. 

So carmakers are more likely to improve aerodynamics instead of expensive start-stop solutions as the cost-benefit shifts. This shift has caused some industry leaders to predict the end of creative car designs – as the science of aerodynamics takes priority over the passion and aesthetics of design. 

tags: Jan-Feb 2015 Exa Corporation Design