The and are pretty much on opposite sides of the spectrum when it comes to the auto market. The Prius is a small, fuel-efficient hybrid sedan that delivers 48 mpg in the city and 45 mpg on the highway. The H2, on the other hand, is a hulking SUV that is estimated to deliver between 10 and 12 mpg (depending on the reporting media outlet). HUMMER H2Toyota Prius
Given the vast difference between the Prius and H2, it seems pretty obvious who would win in an emissions showdown. However, rumors have been circulating for a few years that a HUMMER H2 is actually more environmentally friendly than a Toyota Prius. We take a look at those claims below.
Comparing Prius vs. H2 Emissions
Among other things, the Environmental Protection Agency (EPA) investigates and reports an expected Carbon Footprint for each mass-produced consumer vehicle. This Carbon Footprint attempts to estimate the total amount of greenhouse gas emissions (which consist mostly of CO2) that will be expelled by a vehicle over the course of a year.
The EPA estimates that a 2009 Toyota Prius generates approximately 4.0 tons of emissions each year. Comparing this number to the 2009 HUMMER H2 is a bit difficult, because the H2 is classified as a light truck SUV. Such a classification excludes it from EPA testing. However, independent emissions testing reported by Treehugger.com has estimated that the HUMMER H2 expels 1.46 lbs of emissions each mile. Multiplying this by the number of estimated miles used by the EPA to calculate estimated annual emissions (15,000), and the H2 delivers 10.95 tons of annual emissions.
While this seems high, the actual estimation might be much higher if the EPA actually tested the H2. As reported by the EPA, the smaller offers an estimated 12.2 tons of greenhouse gas emissions each year.HUMMER H3
No Contest, Right? Not So Fast.
Okay, so with almost three times as much greenhouse gas emissions each year, the HUMMER H2 is the clear loser, right? Well, if you are only interested in emissions, then yes, the Prius obviously is a far superior choice. However, recent rumors have indicated that the HUMMER H2 may actually be more environmentally friendly when EVERYTHING is taken into account, from concept to disposal.
CNW Marketing Research, Inc. is a forecasting firm that has taken it upon themselves to estimate and report the approximate energy cost of vehicle models from concept to disposal. The number is calculated based on all amounts of energy that are required to produce, assemble, sell, operate, maintain and dispose of the vehicle over its entire life cycle.
Taking all these factors into account, one might conclude that a vehicle that is more energy efficient on the road actually produces more emissions due to higher energy requirements to build and dispose of the vehicle. At first glance the report indicates exactly that by announcing that the Toyota Prius results in $3.25 of energy costs per mile over the lifetime of the vehicle. In contrast, the HUMMER H2 purportedly operates with $3.03 energy costs per mile. How can this be?
The difference comes largely in the increased efforts required to dispose of hybrid technology materials (such as hazardous nickel). While the CNW study is where the rumors originates, the results of the report do not indicate that the H2 is more environmentally friendly than the Prius. It is important to note that energy costs are not the same as environmental damage. Such a realization outright eliminates the report as proof that the H2 is more environmentally friendly from production to disposal.
Furthermore, many outlets (including Toyota) have argued that the numbers used by CNW to predict energy costs are inaccurate. Specifically, Toyota points to the expected lifetime miles listed in the study. CNW expects the Toyota Prius to only go 109,000 over the course of use, while a HUMMER H2 is estimated to reach 197,000 miles. A separate study performed by Maritz Research indicated that the average Prius vehicle would reach 175,000 miles. Such a figure would dramatically improve the Prius' estimated energy cost per mile.
So, while some reports may indicate the H2 is less costly in terms of energy costs per estimated mile, there is no evidence to support the claim that the H2 is more environmentally friendly than the Prius. Simply put, the rumors draw faulty conclusions from an interesting (though possibly inaccurate) study. In this emissions showdown, the Toyota Prius is the clear -- although not entirely obvious -- winner.