Sorry, you're way off there. My ancient car has a gigantic 90 litre fuel tank. At 720g / litre, that's 64.8kg. And that really is a huge tank - most cars are more like 40-60 litres.
The engine, meanwhile, well it depends what you count as "the engine". If we take it to mean "everything in the engine bay" - radiators, filters, pumps, etc. - you're going to be looking at several times that. Hell, even a battery is like 20kg.
The engine, meanwhile, well it depends what you count as "the engine". If we take it to mean "everything in the engine bay" - radiators, filters, pumps, etc. - you're going to be looking at several times that. Hell, even a battery is like 20kg.