Green FAIL: U-Haul’s Spurious Greenwash Promotes Increased CO2 Emissions

U-Haul is jumping on the low-carbon bandwagon by promoting their ‘clean gasoline’ moving trucks over ‘dirty diesel’, but this blatant corporate greenwash is endorsing choices that actually lead to increased carbon emissions. Have a look at a screenshot from this U-haul webpage:

U-haul is telling us here that using a gasoline-powered truck instead of a diesel truck would reduce CO₂ emissions. This campaign is actually doing more harm than good. It may garner more business for U-Haul, but switching from a diesel truck to a gasoline U-Haul truck will actually increase carbon emissions. This advertising campaign will also lead to indirect carbon emission increases by perpetuating misconceptions about diesel. Let’s have a more careful look at the numbers used here.

The core of U-Haul’s claim of lower carbon emissions is that the amount of CO₂ emitted by burning a gallon of diesel fuel (22.2 lb) is somewhat larger than the amount released by burning a gallon of gasoline (19.4 lb) [Data source: EPA]. So what is wrong with U-Haul’s claim? It is based on the (incorrect) assumption that diesel and gasoline trucks get the same fuel economy. What U-Haul doesn’t explain is that you can do a lot more work with a gallon of diesel than you can with a gallon of gasoline. Diesel fuel efficiency is typically 40% better than for gasoline engines. That’s a huge difference!

The better fuel economy is a result of two main factors: diesel has 11% higher volumetric energy density than gasoline, and the Diesel cycle allows for much higher compression ratios than the Otto cycle used in gasoline engines (which makes for a more efficient engine). In other words, diesel fuel has more energy packed into it per gallon (which is part of why it has higher carbon content), and diesel engines do a better job of converting that chemical energy into mechanical energy used to move the truck.

A valid comparison between gasoline and diesel trucks would be based on equal amounts of work, not equal mpg—this is what really matters to the customer. Consider a potential rental truck customer that has a set amount of stuff that needs to be moved from a specific start location to a specific end location. What we should be comparing is how much CO₂ is emitted from a gasoline truck vs. a diesel truck for moving the same amount of stuff along the same route. If you account for the substantially better fuel economy, the diesel truck will emit far less CO₂ than the gasoline truck. The U-Haul comparison assumes both diesel and gasoline trucks get 8 mpg. For this to happen, the customer would have to remove some of his load from the gasoline truck to improve its fuel economy so that it equals the fuel economy of the diesel truck (which is carrying the full load). In this case the gasoline truck is doing far less work, and is not moving all of the customer’s stuff. The U-Haul comparison strategy is unrealistic and deceptive. Readers who are unaware of diesel’s inherently better efficiency may be misled into believing that choosing U-Haul would actually reduce carbon emissions.

In the fine print above, U-Haul states that ‘actual gas mileage may vary’. The fact that actual gas mileage does vary, in favor of diesel by a large margin, destroys U-Haul’s claim that gasoline trucks are better with respect to carbon emissions. The ‘various reliable sources’ statement in the fine print should raise another red flag: U-Haul is not the least bit transparent about these distorted claims.

In the fine print you will also find links to articles about new regulations for diesel particulate, sulfur, and NOx emissions, which are unrelated to the comparison of CO₂ emissions between diesel and gasoline. Ironically, these articles explain how diesel-powered vehicles will be improved significantly in the near future.

The statement in this advertisement that diesel trucks emit more carbon than gasoline trucks (per gallon) may be deceptive, but it is technically correct given all the stated (but unreasonable) assumptions. The running tally of ‘CO₂ emissions kept out of the atmosphere by choosing U-Haul’, however, is flat-out wrong (flying in the face of the Truth in Advertising Act). Whoever did these calculations didn’t do their homework. Correct calculations would result in a negative value here; that is, switching to U-Haul would increase CO₂ emissions.

On U-Haul’s Corporate Sustainability page you can read:

Avoid “dirty” diesel
Mile for mile, diesel trucks release more toxic air contaminants, cancer-causing soot, and smog-forming emissions than gasoline-powered trucks. Greenhouse gas emissions from a gallon of diesel are 15 percent higher than those from a gallon of gasoline. That’s why all U-Haul rental trucks use cleaner-burning unleaded fuel.

The first two sentences, taken independently, are technically correct. Diesels do emit more particulates and other toxic gasses than gasoline engines on a mileage basis (at least with current emission control standards). And as I explained before, a gallon of gasoline does emit more CO₂ than a gallon of diesel (14.4% more). However, putting these two statements together without clarification may lead people to believe that diesel trucks emit more CO₂ on a mileage basis than gasoline, which is an incorrect conclusion. I roll my eyes at the third sentence. If U-Haul truly was concerned about carbon emissions, they would have transitioned their fleet to more efficient diesel trucks.

The financial savings claim in this ad is also incorrect. Not only do diesel trucks burn less fuel, but diesel is now less expensive than gasoline on average in the U.S. (gasoline: $2.691/gal, diesel: $2.616/gal, Source: EIA, June 25, 2009).

U-Haul is working hard to perpetuate incorrect negative stereotypes about diesel fuel and engines. An anti-diesel campaign magnifies their negative impact by delaying diesel adoption in the U.S. market. Switching to diesel-powered passenger cars could be a practical near-term solution to reducing carbon emissions and reducing dependence on foreign oil. We need to encourage the U.S. market to embrace diesel, not shun it. I want to note that diesel-powered transportation is not a long-term solution; we need to develop (as quickly as possible) a fossil-fuel free transportation system as a long-term solution.

What do you think of U-Haul’s CO₂ marketing campaign? Why don’t you let them know (1-800-789-3638), and see what they have to say about it. Or, you could let others know (like these folks).

As an aside, if you want the ultimate in ‘green’ moving options, and you are moving locally and are feeling athletic, perhaps you would be interested in getting a few friends together for a ‘bike move‘.

Posted: June 25th, 2009 | Filed under: Green FAIL, Transportation |

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