When you mix regular unleaded fuel and unleaded plus fuel in a gas tank it results in a mixture of fuel with an octane rating higher that regular unleaded fuel but lower than the octane rating of unleaded plus fuel.
The 3800 engines with the superchargers require premium gas. Higher octane fuel prevents engine from self ignition of oxygen and gas causing engine misfire.
Yes, this engine requires Premium fuel. Using Regular fuel will cause pinging and engine damage.
Diesel gas gives more mileage (miles per gallon) than regular gasoline. You must, of course, have a vehicle that has a diesel engine because diesel fuel cannot be used in an engine that runs on regular gas! Depending on local government taxation policies, in some countries diesel is cheaper to buy than regular gas whilst in other countries it is more expensive! Diesel fuel is thicker and "stickier" than regular gas so, if a vehicle's fuel system ever needs cleaning - fuel tank, fuel lines, fuel pumps and fuel injectors - it is a more difficult and expensive job to do on a diesel vehicle.
the engine will lock up
Empty your tank out, drain the fuel lines, as the gasoline will damage your diesel engine.
You will get poor fuel economy and reduced power.
Drain the tank, change the fuel filter, refill with diesel.
If you did not start the engine no harm has been done. Drain the fuel tank, and all the fuel lines. Get as much of the gas out as possible. Fill it up with diesel and you should be ok.
You will lose all lubrication to the engine, and if you run the engine long enough you will have catostrophic engine failure.
no/poor gas flow to the engine. Results in stalling/stammerring motor.
== == Automobiles with gas or petrol engines require either regular grade gasoline or super grade. The vehicle's manual will tell you which grade of gas is required. If you fill a vehicle requiring regular fuel with the more expensive super, you are wasting money, as there is no appreciable gain in mileage, engine longevity, etc. However if you put regular fuel into a vehicle requiring super (due to high compression ratio of many sports cars, high-end sedans, etc.) you can cause the engine to knock and cause carbon deposits to build up in the engine. Mid grade can sometimes be used in a mix with super to lower fuel costs, but this is not recommended by automobile manufacturers. If you want to know about using the wrong kind of fuel - in the case of a gas or petrol engine putting diesel in its fuel tank, or putting gas or petrol in a vehicle that has a diesel engine - see the answer to the Related Questionshown below.