> From an environmental perspective, I bet I could drive that truck for the rest of my natural life before I consumed more resources or exhausted more pollutants than would be required to manufacture a new one.

Unless you drive much less than the avarage this is not true, engineering explained [1] did a video about this, and comparing a 24 MPG to a 35 MPG car you produce more CO2 with the 24 MPG car compared to a new 35 MPG car (including the manufacturing) considering your GMC has much worse fuel efficiency that break even point would be much earlier. This is not even considering the impact of recycling... So the best thing for the environment you could do is buy a new more fuel efficient car.

[1] https://www.youtube.com/watch?v=L2IKCdnzl5k

Sorry seems I somehow messed up my post, the overall CO2 budget of the new more fuel efficient car is better after 7 years.

I do in fact drive much less than average; I work from home and mostly drive when doing "farm work".