[Frank Lee]

http://www.epa.gov/otaq/cert/mpg/fetrends/420r08015.pdf

Average vehicle weight and performance had increased steadily from the mid-1980s through 2004.

Each of these marketing groups has lower average fuel economy today than in 1988, with the exception of BMW.

...Figures 8 and 9 are similar to Figures 6 and 7, but show the trends in weight and laboratory fuel economy and show that the era of weight reductions that took place for both cars and trucks between 1975 and the early 1980s has been followed by an era of weight increases until 2005.

Table 1 showed that for the past several years trucks have accounted for about 50 percent of the lightduty vehicles produced each year. MY2004 was the peak year for trucks with 52 percent market share, and trucks have been between 47 and 50 percent since. Considering the five classes: cars, wagons, sports utility vehicles (SUVs), vans, and pickups, since 1975 the biggest overall increase in market share has been for SUVs, up from less than two percent in 1975 to just under 30 percent this year (see Figure 10 and Table 3). The biggest overall decrease has been for cars, down from over 70 percent of the fleet in 1975 to 52 percent. By comparison the sales fraction for pickup trucks has remained constant at 13-15 percent of the market. Figures 11 to 15 compare sales fractions by vehicle type and size with the fleet again stratified into five vehicle types: cars (i.e., coupes, sedans, and hatchbacks), station wagons, vans, SUVs, and pickup trucks; and three vehicle sizes: small, midsize, and large. As shown in Figure 11, large cars accounted for about 20 percent of all car sales in the late 1970s, but their share of the car market dropped in the early 1980s to about 12 percent of the market where it remained for about two decades, but has since increased back to about 20 percent. Within the car segment, the market share for small cars peaked in the late 1980s at about 65 percent and is now lower than at anytime since 1975.

Figures 16 through 20 show trends in performance, weight, and adjusted fuel economy for cars, wagons, vans, SUVs, and pickups. For all five vehicle types, there has been a clear long term trend towards increased weight, moderating since 2005 for wagons, vans, and SUVs.

Since 1988, average fuel economy has decreased for small cars, all wagons, small SUVs, and midsize pickups and the largest improvements in average mpg has been over 20 percent for midsize and large SUVs, respectively.

Cars and light trucks with conventional drivetrains have a fuel consumption and weight relationship which is well known and is shown on Figures 21 and 22. Fuel consumption increases linearly with weight.

Obtaining increased power to weight in a time when weight is trending upwards implies that horsepower is increasing.

Yes, obviously these are cherry-picked quotes (the paper has 96 pages). No, I am not going to research and compile another list of models and weights. Anyhow, the paper is an interesting source for gobs of data folks like us love.