> Bigger cars need more fuel -> bigger fuel trucks
The fuel trucks aren't going to change in size, they're going to come more often. Also, oil is typically distributed in pipelines or on ships rather than trucks until the last mile. Meanwhile a fuel tanker holds some 10,000 gallons of fuel, i.e. enough for "large" 20 MPG SUVs to go 200,000 miles. Meanwhile the tanker is generally transporting the fuel less than 100 miles, so this is diluted by a factor of 2000. Because of the 4th power law, this still causes nearly as much damage as the SUVs themselves, but they're both still negligible compared to all of the other commercial trucks transporting everything else.
Obviously this doesn't even apply to electric vehicles.
> They use more materials to make, require bigger places to store/maintain them and go through bigger consumables ie tires -> bigger lorries.
Yeah, it's not a crazy influence, it's just to point out that the economy is a pyramid and if you make the stone on top smaller, there are thousands of other little places where you can shave weight. Cars account for a small but significant amount of our bulk material usage, think mining equipment -> iron ore -> sheet steel -> stamped parts -> car. If you can reduce the number of F350s we sell, we can reduce the amount of iron ore we're consuming, the size of the ships carrying it, the trucks that haul the mining equipment etc.
The US sells on the order of 4M domestically produced pickups and SUVs per year and produces 1.8MT of steel. If we, conservatively, reduced the weight of all of those cars by half or 1T ea (they're often 3x the weight of a sanely sized vehicle) we quickly eclipse US steel production, even if we exclude some parts as non-steel. That multiplies by 1.6x when you think in terms of iron ore (though most is recycled from scrap).
> If you can reduce the number of F350s we sell, we can reduce the amount of iron ore we're consuming, the size of the ships carrying it, the trucks that haul the mining equipment etc.
But you want to optimize the thing where you get the most bang for your buck.
The heavy side of the most popular SUVs aren't based on the F-350, they generally weigh around 4500 pounds vs. 3500 pounds for the lighter end, the latter being around the same as the average mid-sized sedan. Cutting 30% off of a one-time cost for something that will have a 20-year lifespan is generally not going to be the best place to optimize.
Compare this to, say, introducing mixed-use zoning so people can live closer to their jobs and drive fewer miles. This not only reduces fuel consumption on an ongoing basis, it makes cars last longer because they have fewer miles on them and then you don't need to manufacture as many, and it has direct human benefits because people spend less time stuck in traffic and drive fewer miles with risk of traffic fatalities.
The fuel trucks aren't going to change in size, they're going to come more often. Also, oil is typically distributed in pipelines or on ships rather than trucks until the last mile. Meanwhile a fuel tanker holds some 10,000 gallons of fuel, i.e. enough for "large" 20 MPG SUVs to go 200,000 miles. Meanwhile the tanker is generally transporting the fuel less than 100 miles, so this is diluted by a factor of 2000. Because of the 4th power law, this still causes nearly as much damage as the SUVs themselves, but they're both still negligible compared to all of the other commercial trucks transporting everything else.
Obviously this doesn't even apply to electric vehicles.
> They use more materials to make, require bigger places to store/maintain them and go through bigger consumables ie tires -> bigger lorries.
This is an even smaller effect than the fuel.