The EPA’s Charts On Efficiency, Performance, Weight and Other Metrics, 1975-2016 — Peak Malaise Was Obviously In 1982


(first posted 11/7/2016)   The EPA has issued its “Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends: 1975 Through 2016”report). (The updated report through 2020 is here). It’s a bit long and technical, but I found it quite interesting. But it’s some of the charts that make for the best stories, like this one, which charts calculated 0-60 times. Does this confirm that 1982 was Peak Malaise?



First stop is to look at the big picture of fleetwide adjusted fuel economy, expressed as MPG, over the whole time period. We can see the very rapid improvement from 1975 – 1981,with a 56% increase. That was followed by further but slower improvement from 1982-1987, followed by a steady reversal through 2004. The current favorable trend began in 2005 and has resulted in a 28% improvement since then.


The next chart puts those numbers in perspective, adding in horsepower and weight. The dramatic drop in both hp and weight during the 1975-1981 period directly corresponds to the equally dramatic increase in economy during that same time, given that the technology of the time essentially mandated it. Cars and their engines were drastically downsized as the only viable means to improve fuel economy.

But clearly, the correlation begins to change by about 1985. Horsepower begins a long and steep increase, weight a less dramatic rise. But the drop in fuel economy is modest in relation to them for the first decade or so, but by 2004, economy begins to improve while hp continues to rise and weight stays mostly steady.

The rapidly improving efficiency of gasoline engines during this period is of course well known, due to a number of new technologies. And there’s not really any meaningful trade-off; modern engines can operate at high levels of output, yet also run very efficiently at lower speeds.


Here’s a list of the ten highest fuel economy vehicles since 1975, but using the unadjusted laboratory numbers, not the adjusted ones as commonly used. Not too many surprises, except maybe the Accord Hybrid, which give its weight class, did very well. And for those that will feel compelled to comment about how well the Sprint ER and Metro XFi did without hybrid drive, please keep in mind that they are in a totally different league, in terms of size, comfort, safety, etc..


And here’s the highest trucks. Again, those diesel compact trucks from the 1980s are in a totally different realm.


This chart says it all in terms of how the market has evolved since 1975. The surprise to me was that pickups don’t have as big a share of the market as I might have assumed, given that they’re the top selling vehicles. But that’s a segment with relatively few entrants, compared to the very crowded other segment.

Generally speaking, SUVs are defined as trucks if they either weigh over 6000 lbs and have certain characteristics or have 4WD. There’s other details in that definition, but the point is that “Truck SUV” is not limited to BOF SUVs. So that category is particularly large due to the preponderance of AWD in CUVs.


This chart is a breakout of the chart I showed at the top of this post. please note that these 0-60 times are calculated according to a formula. That may mean that any given vehicle might not be accurate, but it works well enough on a fleet-wide basis. And it certainly shows the huge progress made. And isn’t it a bit ironic that pickups are now the quickest category of vehicle?


Time to look at some trends in driveline technology. Here’s a chart showing the various share for different engine technologies.


Here’s one showing the dramatic improvement of gasoline engine output. The average specific output today of almost 1.4 net hp per cubic inch is phenomenal as these were once a challenge for racing car engines to meet. Of course, the increase of turbocharged engines is having an effect here.


Another chart showing the very impressive linear improvement in gas engine metrics.


Respective shares of engine cylinder count has been shifting, and is clearly heading towards more four cylinder engines, cars and sixes in trucks. The V8’s share is steadily shrinking.


Turbos are playing a big role in boosting the shares of these smaller engines.


Hybrid car and truck share (3 year moving average shown in lines) shows a drop in car hybrids and an uptick in truck hybrids. Low gas prices and the increasing fuel efficiency of non-hybrid cars explains the former; more hybrid SUVs, like the RAV4, explains the latter. Also, the growth of EVs is likely affecting car hybrid sales.


This chart reinforces the shrinking gap between non-hybrid cars and hybrid cars, although it’s pretty subtle here.


But a more apples-to-apples comparison of midsize cars more clearly shows this trend.


Here we look at the changing landscape of transmission types and their respective share.


And here’s one of the reasons why automatics are so common: their fuel economy exceeds that of the manuals.


Is RWD becoming an endangered species?


A graphic representation of new technology adoption over time.


Some manufacturers have adopted certain technologies more broadly than others.

Well, that’s probably enough to digest in one sitting, and to stimulate a bit of conversation.

The 2016 EPA report is here.

The updated EPA report through 2020 is here.