![Exhaust emissions from tailpipe [photo: Simone Ramella, 2005, used under Creative Commons 2.0]](https://images.hgmsites.net/tmb/exhaust-emissions-from-tailpipe-photo-simone-ramella-2005-used-under-creative-commons-2-0_100644014_t.gif)
Last week the Trump administration unveiled a broad drawdown of fuel-economy regulations that had been aimed at cutting emissions from passenger vehicles. In the 978-page proposal, administration officials argued those rules implemented by the Obama administration would create lighter, potentially more fuel-efficient vehicles that would be less...