I can answer this for you and has nothing to do with oil companies. Cafe Standards. You keep adding smog stuff, side impact this, crumple that and you lose mileage
Nail on the head sir. Take the Geo or Miata for instance. VERY lightweight cars. My Miata weighed right over 1 ton because I had a lot of chassis bracing on it a stock Miata weighs 1800ish pounds. Geos are also very light. But there's no way in hell a 1st generation Miata or Geo would pass govt. standards for safety and emissions now days.
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