We've gone through this before. Tougher fuel economy measures will not wipe out trucks, SUVs or fullsize cars. All auto manufacturers will not give up this lucrative market. The ones that do comply with tougher mandates will simply dominate.
The towing capacity on cars didn't fade away because of CAFE in the '70s. Back then cars and especially station wagons were built with body-on-frame construction that supported good towing numbers. Today's cars with unitized construction and a move toward IRS for riding comfort are reducing towing capacity. Today's car engines have more than enough power to tow vehicles, it's the suspension and chassis that are not set up to tow.
And safety won't go away with tougher fuel economy measures, either. The Honda Pilot ranks as a top choice by the IIHS and can still tow 4500 pounds.
It's a ridiculous argument that stronger fuel economy measures will keep Americans from enjoying the outdoors. We're already seeing the heavy-duty truck diesel engines meeting tough emissions standards while improving power. The towing capacity of over 15,000 pounds on those trucks haven't diminished.
Automakers have to be dragged kicking and screaming into improving fuel economy. But they will find a way.