Coal power power for example does not need to cover the deaths directly caused by it's pollution. That's a vast subsidy. Roads revive rather large subsidies from the general funds outside of gas taxes which is another large subsidy, though electric cars revive even larger subsides by not needing to pay for their use.

PS: Look at taxes for Farm use vehicles fuel to get a better picture of the actual 'subsidy' vs 'tax'. The tipping point is very much a subsidy. https://www.irs.gov/businesses/small-businesses-self-employe...