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Motor Mouth: Why new-car fuel economy numbers are so depressing

The automotive internal-combustion engine has become massively more efficient over the last 20 years. Handout/GMC
The automotive internal-combustion engine has become massively more efficient over the last 20 years. Handout/GMC - POSTMEDIA

Perusing the U.S. Environmental Protection Agency’s latest Automotive Trends Report is both surprisingly uplifting and discouragingly demoralizing. It marries the ingenuity that remains mankind’s greatest attribute with the willful hypocrisy that is its worst. The only real surprise to the study is who’s to blame for the woeful state of automotive tailpipe emissions in North America.

Whatever you might think of internal-combustion engines (ICEs), however you might feel about the willingness of mainstream automakers to effect positive change, and whether you believe they do so only when their feet are held to the (emissions regulations) fire, the fact remains that the automotive ICE has become massively more efficient over the last 20 years. Credit turbocharging, multi-speed transmissions, and stop-start functions to name but a few innovations, but automakers have responded — again, feet to the fire — with far cleaner and more miserly engine technology since governments started taking the automobile’s effect on climate change seriously.

According to the Society of Automotive Engineers, the very best of ICEs — the Toyota RAV4 Hybrid’s 2.5-litre four, for instance — claim a peak thermal efficiency of about 41 per cent, an incredible figure that is more than double that which was the norm a couple of decades ago. Essentially, that means more of the energy released during the combustion of gasoline is used to power the pistons (and eventually the wheels) and less wasted through friction and heat loss.

Nor is Toyota the only manufacturer making dramatic leaps in high-tech spark ignition. According to the EPA, fewer than three per cent of vehicles in 2008 boasted gasoline direct injection (GDI) — wherein high-pressure fuel is squirted directly into the cylinder rather than the less efficient injection into the intake manifold — compared with 55 per cent today. Stop/start — which shuts down the engine when idling at a stoplight — is now standard on 42 per cent of all cars.


The Toyota RAV4 Hybrid’s 2.5-litre is one of the most efficient internal-combustion engines available. Handout / Toyota - POSTMEDIA
The Toyota RAV4 Hybrid’s 2.5-litre is one of the most efficient internal-combustion engines available. Handout / Toyota - POSTMEDIA


Some manufacturers have committed completely to emissions-reducing technology. For example, according to the EPA report, all Mercedes products are available with GDI engines and transmissions with more than seven gears (which allow the engine to operate closer to peak efficiency). Ditto BMW, which is at 99 and 98 per cent in the same categories. Ninety-four per cent of Subarus come with continuously variable transmissions (same benefits as multi-speed automatics) and a whopping 60 per cent of Mazdas can deactivate cylinders to reduce fuel consumption when cruising. In other words, automakers are, whether you think it coerced or voluntary, dramatically improving the efficiency of their powertrains.

But what have we, the consuming public, done with all this newfound efficiency?

Why, we’ve pretty much wasted it all by buying bigger, more powerful, and less aerodynamic vehicles as fast as we can. It’s no mystery that we’re buying more pickups and SUVs than ever before. For instance, in its fuel economy and emissions regulation, the EPA divides sport-utility vehicles into two categories; those based on cars and those on trucks. The difference in the “regulatory definitions” defines truck-based SUVs as those having AWD or a gross vehicle weight of more than 2,720 kilograms, a heftiness made all the more significant by the fact that fully 37 per cent of all vehicles sold in the States (Canada’s numbers are not markedly different) were such truck-ish SUVs. Combined with the 16 per cent of the market dominated by pickups, that means well over half of all vehicles sold in 2019 were trucks.

Throw in the 12 per cent that car-based SUVs represent and you have fully two thirds of the market dominated by vehicles inherently less fuel-efficient than the smaller, lighter, and more aerodynamic sedans they are replacing. In other words, we’re taking all that newfound efficiency and using it as an excuse to buy bigger vehicles. Hence why, according to Michael Sivak, managing director of Sivak Applied Research and the former director of Sustainable Worldwide Transportation at the University of Michigan, the average vehicle sold in the U.S. only increased its fuel economy by 0.4 miles per US gallon between 2008 and 2019. It’s also why Ford and GM were two of only three major manufacturers to see a decrease in fleet fuel economy between 2014 and 2019 and why, Ford, GM and Stellantis remain mired at the bottom of the EPA’s fuel economy and CO2 charts.

But, as Ron Popeil used to say, “Wait, there’s more!”

Since 2004, the EPA says, power is up some 16 per cent on average across the entire American fleet. As I said, much of the efficiency that turbocharging and direct injection have wrought has been directed either toward performance or compensating for the greater weight of vehicles instead of reduced fuel consumption and emissions.

That still doesn’t tell the whole story. In charting the horsepower increases of the average car since the early ’70s, the EPA says horsepower has increased a whopping 75 per cent. In fact, the only significant decline in an otherwise steady march to more power happened between 1975 and 1980 when, for the only time in recent automotive history, both the amount of power the average car produced and the size of vehicle the average North American bought dropped by almost a quarter. That was, of course, the result of 1973’s infamous oil crisis, which saw oil prices spike as much as 400 per cent, and heralded the petroleum shortage that still haunts us today.

So, what to make of all the macroeconomics? The first thing coming to mind is that the inevitability of electric vehicles may have as much to do with the selfishness of consumers as it does with the inherent superiority of electric powertrains. Although the average fleet fuel economy has increased somewhat over the last 20 years, most of the efficiencies that automakers have built into the modern internal-combustion engine have been used by consumers, as the statistics so emphatically illustrate, to move up to a larger, heavier class of vehicle. Had we instead made the oil crisis’ shift to smaller cars permanent and applied more of those internal-combustion efficiencies to emissions reduction, maybe we wouldn’t be so desperate in our rush to electrification. At the very least, the automobile’s contribution to global warming would have been reduced.

The other thing worth noting is that the only time consumers make worthwhile changes is when it affects our pocketbooks. Yes, studies continually remind us buyers say they want to reduce their impact on the environment, but, as dispiriting as it is to say, the truth is that the average consumer only changes their habits when they are hit hard — make that very hard — in the wallet. Trying to marry the studies that claim the environment is the most important thing on Canadians’ minds with the number of people decrying carbon pricing suggests a hypocrisy we all should be ashamed of. Purchase decisions always speak much louder than focus groups, and right now the cars we’re buying say we don’t give a damn about the environment.

If I were an optimist I would be hoping that consumers make the move to electrification — PHEVs and fuel cells as well as battery-powered cars — simply because they offer both the power and heft demanded. They sure as s#!t aren’t going to go electric because it’s the right thing to do.

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