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September 26, 2018

Letter to EPA IG Requesting Investigation on Glider Truck Study Conducted by Tennessee Technological University


Letter to EPA IG Requesting Investigation on Glider Truck Study Conducted by Tennessee Technological University



Glider kits were traditionally used to help salvage the engines of damaged trucks and include the frame or chassis, front axle, and body/cab components. They become a glider truck when an engine, transmission, and rear axle are added. However, glider trucks normally use older engines that do not have modern-day emissions controls that help substantially limit toxic emissions from their engines. In 2016, the federal government helped to close this regulatory loophole by limiting the number of glider trucks each glider kit manufacturer could produce that escaped environmental regulations. They could still produce as many trucks as they wanted that complied with federal environmental regulations.

In November 2017, the EPA issued a proposed repeal of the glider truck rule that would have eliminated any environmental controls over the glider truck industry. As part of that proposed repeal, the EPA cited a June 2017 summary of a study from Tennessee Tech University (TTU) that concluded glider engines performed on par with or better than conventional engines. That study has come under extraordinary criticism from the university’s own faculty, as well as environmental experts as well as trucking industry officials, and sparked an internal investigation by the university. A February 2018 memorandum from the Interim Dean of TTU’s College of Engineering, for instance, said the glider study’s summary results included the “farfetched, scientifically implausible claim, that remanufactured truck engines met or exceeded the performance of modern, pollution-controlled engines with regards to emissions.” 

After the EPA used the study to help justify its repeal of the glider rule, the President of Tennessee Tech wrote to EPA and told them not to refer to the study in any way until the university’s internal scientific misconduct investigation was completed. The university has not publicly announced the status of this investigation, which, according to TTU’s own policy, should have been completed months ago.