Tuesday, July 18, 2006

US Cars are Bigger and Faster, but No More Efficient

There was an article posted today on CNNMoney.com (available here) that discusses how today's vehicle fleet is the largest and most powerful that it has been in 30 years (More than 30 years ago was during the 1960s muscle car era that meant big cars and big horsepower...which ended with the first Arab oil embargo in 1973. Following another oil shock in 1979, American cars shrank in size and horsepower dramatically, but have grown steadily since the early 1980s as memories of the oil shocks faded and more power and interior space became attractive again.)

This was the bottom line of the article, from its last paragraph:

Since 1992, average fuel economy as measured by the EPA has been relatively constant, ranging from 20.6 to 21.4 mpg. This 21.0 mpg value is 5 percent lower than the fleet-average fuel economy peak of 22.1 mpg achieved in 1987-1988.
Since you asked (ha, ha), my take on this is that it's pretty simple logic to assume that when automobile manufacturers come up with the technology to improve efficiency of engines, they have two choices - improve economy and keep power constant, or improve power and keep economy constant. Because cars and trucks have gotten heavier for the past 20 years following the late-70s/early-80s downsizings as they got bigger and more safety equipment, power accessories, etc. were added, manufacturers by and large decided to keep economy relatively constant but to improve power.

I love high performance cars, and I love horsepower and the horsepower wars we are seeing today, but at some point, I have to wonder how much power is enough power in a family sedan. In my opinion, once we start seeing 275-300 horsepower Accords, Camrys, Altimas, Malibus, Fusions, etc. (not just in the limited-production high-performance models, either) and light duty pickups with 750 lb-ft diesels, I think it might be time to direct future advancements toward economy improvements and keep the horsepower constant. Of course, absent a sustained major oil supply disruption, that will probably not happen.

I sometimes wish my Accord had more power (it has 240 horsepower), but really, I spend 98% of the time with the accelerator pressed down maybe 10% of its total travel.

The EPA's news release about this has a really interesting chart, which I saw for the first time in today's Wall Street Journal. It illustrates the average weight, horsepower, and fuel economy of a new car in 1975, 1987, 1997, and 2006. Here are the more interesting points:

Avg economy: 13.1 mpg
Weight: 4,060 pounds
Horsepower: 137
0-60: 14.1 seconds

Avg economy: 22.1 mpg
Weight: 3,220 pounds
Horsepower: 118
0-60: 13.1 seconds

Avg economy: 20.9 mpg
Weight: 3,720 pounds
Horsepower: 169
0-60: 11.0 seconds

Avg economy: 21.0 mpg
Weight: 4,142 pounds
Horsepower: 219
0-60: 9.7 seconds

Part of the above numbers are because of the reason discussed above, but part of them are also because of the proliferation over the past 30 years of four wheel drive vehicles and trucks, which are heavier and get worse fuel economy. The EPA also gave these statistics for each year:

Percent of total sales that are truck sales: 19%
Percent of total sales that are four wheel drive: 3%

Percent of total sales that are truck sales: 28%
Percent of total sales that are four wheel drive: 10%

Percent of total sales that are truck sales: 42%
Percent of total sales that are four wheel drive: 19%

Percent of total sales that are truck sales: 50%
Percent of total sales that are four wheel drive: 29%

So, our fleet fuel economy can't get much worse from this point forward, right? ;)

No comments: