On the basis of vehicle weight, how dramatic has the increase in fuel economy been over the past 45 years?
Well, here's an unscientific observation that might be surprising.
This week I was running through some old news articles, seeking information for several stories I'm writing for Automotive News' special issue devoted to Chevrolet's centennial. The issue will be published Oct. 31.
What caught my eye was a story about the Mobil Gas Economy Run that was held back in 1966 and the two sedans that captured first-place finishes. The event was sanctioned and operated by the United States Auto Club.
In the days before the government required automakers to post a vehicle's fuel economy on a window sticker, consumers interested in miles per gallon relied on the Mobil Gas Economy Run. Cars traveled across the country on roads typically encountered by regular drivers to give consumers a real-life scenario. The event ran from the mid-1930s to around 1968. The 1966 event started in Los Angeles and ended in Boston, 3,301 miles later.
The economy run was divided into several categories and included cars from the Big 3 along with the smaller U.S. automakers, such as American Motors and Studebaker. The imports apparently were not invited.
To make sure no one cheated, my understanding is that each car was purchased at a dealership and the hood was sealed. The gasoline tank was disconnected and a special tank that could be monitored was placed in the trunk. The coverage back then didn't say if the cars ran with air conditioning, but it's a pretty good bet they didn't. Few cars had that luxury back then.
Each automaker touted a winning entry in advertising. You can catch a TV ad for Buick's 1964 models on YouTube.
The winner in what was called the standard-sized category was a big six-cylinder powered 1966 Chevrolet Biscayne full-sized sedan, with 21.04 mpg. The car weighed 3,294 pounds, according to the story that appeared in the Dallas Morning News. The winner in the compact category and overall winner was a six-cylinder powered Rambler American compact sedan, at 23.80 mpg. The story said the Rambler weighed about 800 pounds less than the Chevy.
I decided to compare those cars to two 2012 cars with similar vehicle weight to see the differences in fuel economy, 45 years later. Obviously, the length, width and height of the 2012 models are somewhat reduced compared with cars in the '60s. The new models have far better aerodynamics than the Chevy and Rambler. Additionally, the 2012s compared here have four-cylinder engines.
The 1966 Chevrolet Biscayne weighed 3,294 pounds and averaged 21.04 mpg. I used a base 2012 Ford Fusion sedan with automatic transmission for the comparison. The Ford weighs 48 pounds more than the Chevy and gets 23 mpg city, 33 mpg highway and 26 mpg overall, according to the EPA.
The 1966 Rambler averaged 23.80 mpg, coast-to-coast. For a weight comparison, I used a base 2012 Honda Civic with an automatic transmission. The Civic weighs 2,608 pounds, and is rated at 28 mpg city, 39 mpg highway and 32 mpg overall.
Using the EPA's overall miles per gallon numbers, the Fusion was 5 mpg better than the Biscayne and the Civic was about 8 mpg better than the American.
Was there a dramatic difference in fuel economy 45 years later on the basis of vehicle weight?
In this particular case, I guess it depends on how the numbers are interpreted.