Are our Cars Getting More Efficient?

One of my earlier blogs looked at ways to reduce our own personal emissions to meet the Provincial climate action plan target of a 33% reduction from 2007 levels by 2020. While removing car trips entirely is of course preferred, it is not realistic for everyone, accepting that many people do not want to, or cannot feasibly give up their cars due to work requirements or lack of suitable alternatives, can improved designs and technology or a change of vehicle type achieve the targets?  Read on...

National Resources Canada produces a list of all fuel economy ratings and goes back as far as 1995. The list excludes purely electric vehicles. Interestingly, looking at the most efficient vehicle in 1995 and 2015, there isn't a dramatic difference. In 1995 the Geo Metro was the most efficient with a combined rating of 5.9 L/100km, in 2015 the Toyota Prius is the most efficient with a combined rating of 4.7 L/100km. It doesn't seem like a large difference but it is a 20.3% reduction. In 2007, the base year for the action plan targets, the Toyota Prius was again the most fuel efficient at 5.1 L/100km combined, so there has been a 7.8% improvement since 2007. This example is at the most fuel efficient end of the spectrum, how would a range of different vehicle types fair over the last 20 years?

1995 Geo Metro 5.8 L/100km

2015 Toyota Prius 4.7L/100km

The chart below provides examples of several different types of vehicle available from 1995 to 2015. I have selected the most fuel efficient model in each year as engines vary by year. Testing methods may vary over the years also, new measures implemented for 2015 model year try to provide more realistic ratings by introducing heavy acceleration into the tests.

Fuel Efficiency 1995-2015

The average improvement from 1995 to 2015 for the above vehicles was just 15.7%, meaning if you stuck with the same type of car over the last 20 years, emission reductions are not significant enough to meet those targets. Efficiencies have been gained through engine, transmission, lighter materials and aerodynamic improvements, but lost to increased vehicle size and more safety features and equipment adding weight.

Changing vehicle type has the most profound effect. Changing vehicles from a large SUV or truck to a smaller vehicle can dramatically reduce emissions, even exceeding the climate action plan targets. You don't have to downgrade to a "dull" car either, changing from a Jeep Cherokee to a VW Golf GTI, provides a 43.5% reduction in combined fuel economy. Do you really need that large vehicle? Think of the fuel savings, and therefore gas tax savings from moving to a smaller vehicle!

Of course electric vehicles are changing things significantly and are not considered in this example. In BC, where our electricity comes from hydro power rather than polluting sources of electricity generation, they offer a much greater advantage. We have 5 years left until 2020, when those targets were supposed to be achieved. This is perhaps too soon for electric vehicles to solve the emission reduction challenge entirely. However, over time they will become increasingly common. While they will solve the air quality issues in our cities, they will not solve the congestion issue. To do that we still need suitable alternatives.