https://www.goldeagle.com/tips-tools/how-long-does-diesel-fu...
Ammunition is tricky because there are so many "denominations" (i.e. calibers). It would certainly come in handy. One of the biggest benefits of the M16 for the US military was that it was standardized, meaning every branch used it and they all used the same caliber.
I think canned food would be important too. Quite a revolutionary concept we take for granted (we can thank Napoleon). Fun fact, canned food was invented 48 years before the can opener.
I think drugs and alcohol would be a huge currency. Always have been in one form or the other.
Of course most people in cities would be hosed after the canned food ran out, unless there was a severe population drop.
Read the book "Alas Babylon," it is a good fiction about nuclear war.
As impractical as it seems at first glance, the best post-apocalypse vehicles (barring an EMP scenario) would be electric since scavenged solar panels could provide the energy source for generations without significant degradation. Scrounging for electricity-based energy generation is much more practical than petrol-based resources that degrade, need refining, etc.
Batteries won't last as long as the solar panels, but as a personal observation, I've noticed that my parents hybrid Prius still has over 95% battery health after almost 15 years. High-quality batteries with well-engineered charge controllers have really impressive life spans in terms of maintaining their charge capacity!
Note: This has no impact on your argument. I only mention it because I love me some physics.
Here's a citation, if you're curious:
https://physics.stackexchange.com/questions/34421/does-the-m...
The short version is that it will have less mass when the battery is discharged. However, you're not going to be able to detect a difference on your bathroom scale.
Again, this is being posted as a mere factoid and not meant to argue your point.
The other problem is generating the energy. Yes solar panels are a good energy source in an apocalyptic scenario, but the power they give out is really limited compared to fuel. 10m2 of solar cells will generate around 5kW per day (assuming no nuclear winter). With current EVs that would give you a range of around 10-15 miles once charging loses are taken into account.
https://groups.google.com/forum/#!topic/comp.society.privacy...
This is, of course, assuming society starts to reform and not all knowledge is lost. There will still be pockets of tech and society left, and there will still be power sources that stay running - like hydro.
Humans are pretty resilient and adaptable. If we don't kill the entire population off, we will probably be okay. Maybe not okay as an individual, but okay as a species.
Ammunition is the universal apocalyptic currency. You can hunt with it and you can protect your family, food, and possessions with it. It is shelf-stable and easily subdivided. It can be put in a box and buried or carried in your pocket. Lots of people own guns but few have significant stashes of ammunition. A staple of chaotic times.
Water, that’s obvious, but you need a way to collect it and clean it. Those are their own currencies.
Diesel powers computer-less trucks like my old Land Rover Defender 110. Probably the last running vehicles in an apocalypse. It also runs generators and water pumps. It can potentially be manufactured by civilians.