Ever wondered why engines could run dry without seizing up? Want just a little bit more realism? This mod might just be for you.

This mod adds oil (crude) to the engine recipe. It also tweaks the technology tree to accommodate the new recipe changes by moving engines (and pumps, which require engines) behind oil gathering.

My other mod (optional) - Chemical Science Uses Petroleum https://mods.factorio.com/mod/chemical-science-uses-oil changes the tech tree to not require engines for Chemical Science as engines are removed from that recipe

This change will make cars and trains slightly longer to unlock and ever so slightly harder to craft.

There are two options in the startup settings both off by default:
Expensive mode - which doubles the requirements of steel and iron gears to 2 from 1
Add Iron Sticks - recipe also requires 2 iron sticks (a cam and crank shaft)

Mod based on the idea of Engine Units Need Lube by vertani, which I liked, but found it difficult to integrate into a game easily as engines were too far down the tech tree. So, I made my own version.
This is my first mod so might not work on all mod load-outs.