Currently in 3.0, we have pumpjacks that draw fuel periodically from the ground. Personally, I think this is complete bullshit. First of all, I doubt that oil is this close to the surface, and second of all, I doubt that it can be found everywhere on the map. In addition, raw oil would also have to be refined in order to be properly used in combustion engines.
In 4.0, I feel that pump jacks should still be a thing, but oil reserves will have to be regulated to a few select locations per map. In addition, the cost to craft a pumpjack would have to be significantly more expensive, and the oil that is produced will have to be refined.
Instead of pumpjacks for all, I hereby introduce the gasification process.
Gasifiers operate on a principle that when combustible organic matter is exposed to heat but sealed off from oxygen, it will decay into a gaseous mixture of hydrocarbons. When condensed, the resulting liquid can burn in any internal combustion engine.
Two craftable items would probably be needed for this, a gasifier and a condenser.
In addition, the gasifier will have to be fueled with combustible material in order to generate the heat nessecary to vaporize the organic material within the vacuum chamber. A hand-powered air pump will also be needed to achieve the vacuum nessecary for the reaction.
Now, pumpjacks will never be fully replaced. Pumpjacks have a massively superior production rate compared to any gasifier system, allowing them to pump out vast amounts of fuel compared to a gasifier. However, for normal survival use, the gasifier reigns supreme.
Onto my second topic: stills.
No, I am not pushing for alcohol production (though that could easily be possible with stills), I am referring to the vaporization of polluted or salty water to remove any pollutants, and then condensing the resulting water vapor back into its liquid form.
There are two types of stills, solar and combustion-based. The former, as its name suggests, relies of the light of the sun to evaporate the water, using a vapor barrier to trap the water vapor and force it to condense at a single point, causing the pure water to drip into a collecting container below.
Here is an image depicting this contraption:
As you can see, such a device can easily be made to purify water early-game. Later, a regular still can be made:
Tha larger container is where the polluted water is contained, a fire is lit under it. The vapor travels through the piping to the condenser on the right, where a coolant (likely more polluted water) surrounds the pipe and forces it to condense.
In conclusion, both gasifiers and stills will allow fuel and water production without having to find purification tablets or building mechanically complicated pumpjacks.