Originally Posted by Maggs
Can someone explain what the difference is between gasoline and diesel? I'm lost. Is diesel cheaper than gas? Does diesel have better MPG?
I asked a friend if he knew anything about diesel, and he said he does not even know if it's easy to buy. Is diesel like leaded fuel? Are there disadvantages to diesel? Can any mechanic work on a diesel engine, or do the cars need to be serviced in expensive shops?
Do diesel powered Mercedes last longer than gasoline powered Mercedes? What is the average lifespan of a diesel powered Mercedes? 200,000 miles? 300,000 miles? more?
I want to buy a used Mercedes that will last a long time, and people recommended a diesel. I'd like to learn a little more about them before I buy one.
1. About 30% better fuel mileage since diesel fuel contains more BTU's per gallon.
2. Simplicity of the ignition sytem since there are no spark plugs, spark plug wires, distributor or ignition coil.
3. Better engine life since the fuel is a lubricant unlike gasoline which is a solvent that can wash the oil from the cylinder walls.
4. Better fuel economy in stop, idle, and go traffic as diesels do not have to maintain the stociometric 13.8 ratio of air to fuel that gasoline engines do. In other words at low loads, diesels run very lean compared to gas engines.
5. Torque is best at low RPM's
6. Diesels love to be run for long periods of time
7. A "tune-up" is a change of the filters and crankcase oil.
1. Dirty Fuel can plug fuel filters fast..Never had this problem.
2. Hard to start in extremely cold weather....Never had this problem.
3. Filters MUST be changed regularly. The injection pump and injectors are expensive.
4. Crankcase oil becomes black rapidly from soot on cylinder walls.
5. Cold weather can cause fuel to gel, though modern fuel being sold is mixed with kerosine as the winter blend to absorb moisture and decrease low temp viscosity..Never had this problem.
6. Oil companies have priced Diesel fuel higher than premium in the Northeast since it has more BTU's. It used to be less expensive since it required less refining.