Um... because they have an engine like your car that has moving parts and cylinders... only significantly smaller?
To lubricate the motor to prevent overheating and wear and tear on the engine
Two-cycle lawnmower engines are rare.
Lawn tractors have oil filters.push mowers don't. Change oil more frequanetly in a push mower engine.hope this helped. S.g.
Most all riding mowers use SAE 30 oil.
Lawn mowers can take 2 stroke or 4 stroke oil depending on the type of engine. If unsure contact your lawn mower provider.
Scythes.
generally a quality 30 weight
No. Do not use in your car. It is for use in some lawn mowers and aircompressor motors.
It can vary between 30W and 10W30. L-heads use 30W, OHVs often use 10W30.
Lawn mowers are not destroyed after a single use, and they retain usefulness for many years, so, yes, lawn mowers are durable goods.
The majority of lawn mowers are not robots. That is not to say that all lawn mowers are not robots. Some companies have been manufacturing robotic lawn mowers (Lawnbott, Norman, etc.)
20-50 motor oil