What is the difference between marine diesel and diesel?

Answer 1

The difference between marine diesel and road diesel is twofold physical and legal use. Fuel and engine wise there is no difference marine diesel (has red dye) and road diesel (has green dye) all diesel engines are color blind, so the same engine will run the same diesel whether is has green or red dye.

So you ask what is the big deal about using marine or road diesel?

The answer is government regulation.

Part Two

The green diesel has taxes paid to the governments maintaining the roads which the diesel vehicles use (and wear down) where they buy the fuel. The more fuel you buy the more road wear you cause, the more road tax you pay. Marine/farm use vehicles which do not run on roads cause no road wear so pay no road tax. This makes the marine diesel cheaper in some areas almost half the price, because of the high local tax rates. Cheaters put marine fuel in road vehicles to save money and cheat the local governments which results in poorly maintained roads. It is typically illegal to put marine diesel in a road vehicle, it is done more often than you think, typically by liars who try to tell you there is an additive or performance difference between the two. The red or green dye causes no performance difference.

So what are legal uses of marine diesel on land? The answer is simple, on stationary diesel engines like generators and fuel oil heaters and boilers (items which never touch a road). These uses are not only legal but make good fiscal sense. Certain farm and earth moving equipment and industrial equipment like plows and forklifts which never go on the street can use marine diesel, however if their tires ever touch a road they must always use road diesel. Towing where their tires touch the road still causes wear and still requires that the tax is paid.

I have been doing this for more than four decades and have filled out the tax forms to go with it. I have worked both on the refinery side and the end use side both on and off road, in civilian, military, and emergency response. This is the correct answer.

Answer 2

Most difference in the Dimensions. Bigger ones are two stroke with cross head. Coolant and lubrication oil are cooled by see water normally. If You mean fuel than marine diesel fuel has lower standard for sulfur contents and cleanness. There is special fuel treatment system on board like settling tanks, purifiers, fine filters etc