DERV stands for Diesel Engine Road Vehicle
to cool engine
Diesel with water in it will blow the ends off the fuel injectors, which is why maintaining your water separator is so important.
That is the fuel filter on the driver side of the engine block.
Diesel engines are sold by almost every vehicle manufacture.
Yes it is possible to push start a diesel engine vehicle.
Flex fuel does not mean you can use diesel. It means the engine can run on pure gasoline or on E85 gasoline. If you put diesel in this vehicle it simply will not run. Diesel can only be used in a diesel engine.
They are charged by their gas or diesel powered engine.
Glow is probably for "glow plug" which is a diesel engine application. If your vehicle isn't diesel, it had that option as an engine, so that fuse would be found empty in your vehicle. If your vehicle is a diesel, a blown fuse here would lead to a "hard to start"or "no start" issue.
Engine oil and engine oil filter(s), air filter(s), fuel filter(s) and fuel system water separator if applicable.
if it is a diesel it is built in to the fuel filter that is on top of the engine. on the 7.3l there is a yellow lever on the back of the housing that you can drain the water/fuel from it
Should be located at the top rear section of engine - unscrew, remove and clean water separator