Better to use the batteries than hauling around mostly unused batteries all the time.

Plug in hybrids need to haul around an engine, gas tank, transmission, exhaust system etc. They also need extra batteries over a standard hybrid.

Those items aren’t made with as much extractive materials proportionally as EV batteries. If using PHEVs means more miles travelled are electric while less lithium is mined, great.

If you’re replacing the battery then you still need to extract those materials. Thus weight is only really meaningful in terms of vehicle efficiency not materials extraction. And of course having a plug in vehicle doesn’t mean it will be driven as a plug in vehicle where EV’s are limited to pure electricity.

There’s more aluminum and steel available above ground than lithium.

There is unused capacity, but all batteries in an EV are used slightly over a commute. That can lead to a much less damaging wear-pattern on the batteries, extending their life by a lot.

LFP batteries have practically unlimited recharge cycles.

Higher density LFPs are coming too.

I would agree in general with the parent, but with LFPs hitting mainstream 200-300 mile range in pure EVs, and no real resource constraint, hybrids and "standard range" can be LFP and then NMC chemistries can be dedicated to higher density needs.

10kWh LFP’s don’t last the lifetime of the average plug in hybrid due to regenerative breaking adding a lot of charge cycles when total battery capacity is that low.

30m/s to 0 on a 2000kg vehicle = 900000 J or 0.25kWh, on a at best 10kWh battery adds up.

Really? I remember Jeffrey Dahn saying they were effectively unlimited, for whatever LFP chemistry they were testing, back when the million mile battery was being advertised.

Also LFPs don't have sourcing issues, and I think the minimum range hubrid should be 70 miles, so that would be bigger than 10kwr.

If 10kwhr is only 20-30 miles... I think we should have 25kwhr at a minimum. 20-30 miles becomes like 10 miles in deep winter, and even then the ICE is doing the heat/cooling. You need 70 miles to handle weather range degradation for that sweet 50 mile daily usage range.

Bumping things to 25kWh vs 10 kWh and sure that can last the lifetime of the vehicle, but it also means replacing 1 EV with ~3 plug in hybrids vs 8 that the original poster mentioned. And you now have to manufacture and maintain 3 ICE powertrains which further cuts into the savings.

Plug in hybrids can be a great option for many drivers, but IMO they they essentially inherit the downsides of both EV’s and ICE. For example they have issues sitting unused for long periods. Need to replace belts and spark plugs etc. They risk both a battery fire and gasoline fire etc etc.