Regarding safety related weight, there's a very interesting and thorough study from Berkley, I'd recommend reading, if you want to be nerdy.

[1] https://are.berkeley.edu/~mlanderson/pdf/anderson_auffhammer...

The International Energy Agency has done some good research specific to the subject of SUV emissions.

[2] https://www.iea.org/commentaries/global-suv-sales-set-anothe...

[3] https://www.iea.org/commentaries/as-their-sales-continue-to-...

And specific to weight, it's topic that is not ignored by federal or state regulating bodies. Heck, even 10 years ago the EPA stated if reduce the weight of your vehicle by 100lbs you can achieve 1-2% fuel improvements. And weight removal is the opposite of diminishing returns, so every pound reduction yields better results.

[4] https://afdc.energy.gov/files/u/publication/10_G00888_saving...