Can a car be converted from gas to diesel?

Answer 1

Yes, but only by installing in place of the existing "gas" (i.e gasoline) engine a diesel engine that was made for your model of car. For many technical reasons it makes no sense to even think of "converting" a gasoline engine into diesel engine because many things are actually impossible to convert: * the engine's block and cylinder head do not have sufficient strength to take the very high compression pressures required for burning diesel fuel; * the engine's crankshaft and piston rods cannot be modified to handle the necessary - and much higher - fuel/air compression ratio that is required for burning diesel fuel; * the engine's pistons, piston rings, camshaft and cylinder head valves are all of the wrong specification to handle diesel combustion; * the engine will require a diesel injection system instead of the existing spark ignition system; * the engine's electronic control unit will be totally different; * etc. !!! That list of required changes are what would be needed just for the engine itself. In addition, changes will almost certainly be necessary to the engine's cooling system and its exhaust system...

Depending on the particular car make and model, there may be plenty of good secondhand diesel engines available from breaker's yards, taken out of crashed vehicles. But then, of course, you would have to get the engine - and everything else necessary to run it and control it - properly and safely changed-over. The labor and parts costs would probably total very much more than the cost of trading-in your gasoline car and buying the equivalent diesel model.

So, unless you are already a car repair specialist - in which case you probably wouldn't be asking this question here - doing such a conversion to a car is not really a practical project.