Hybrid vehicles always had a fuel economy advantage in urban driving but new data show that they are gaining on diesels in highway driving. If current trends persist, hybrid electric vehicles (excluding plug-in hybrid electric vehicles) are set to take the lead in 2017, according to the highway mpg for diesel vehicles and gasoline hybrids as tested by Emissions Analytics.
However, the downturn in diesel mpg may be due to a change in manufacturers’ focus from fuel economy to NOx emissions after the Volkswagen Dieselgate fraud. Nonetheless, there clearly is an improvement in gasoline hybrid performance because of technological advances. (Long-Time Volkswagen Engineer Pleads Guilty to Criminal Charges for Rigging Tests on Dirty Diesels or Diesel Emission Fraud Charges Hit Volkswagen Group Profits)
The technology is more noticeable when the European EQUA Index data is compared to North American EQUA results. “Gasoline hybrid performance in the US is particularly impressive on our combined cycles. With this level of fuel economy, it seems unlikely that diesel vehicles will ever make a significant impact on market share in the US,” said Emissions Analytics. “With the mpg penalty of some NOx after-treatment systems, perhaps it was to gain a fuel advantage over hybrids that Volkswagen resorted to using a defeat device when bringing their diesel models to the US market.”
Another noticeable effect of the different product mix in the US is the level of carbon monoxide emissions. Both regular gasoline cars and gasoline hybrids have much lower CO emissions than their European equivalents, with gasoline vehicles 30% lower and gasoline hybrids 64% lower. This exists with the US have a less strict limit, at 2.1g/km, than the EU’s, 1.0g/km limit. The US enforcement and compliance mechanisms are much stronger, of course, as VW Group is coming to understand. ($14.7 Billion Volkswagen Diesel Fraud Settlements)
“When we last wrote about hybrid vehicles back in October 2014, we concluded they were delivering good, but not best-in-class fuel economy, but [were] typically the cleanest, and if you are a light-footed, congested town driver, they are ideal. Two years on hybrids, particularly in the US, have really upped their game. They are still a cleaner drive than a diesel and may soon offer better fuel economy wherever you drive them but heavy-footed drivers should still exercise caution,” said Emissions Analytics.