Which will be more efficient in term of fuel price:

  1. Transport via roadways, say truck or motor vehicle.
  2. Transport via waterways, say via ship or motor boat.


Same caliber engines (same power) are used in either ways. Fuel is same. The distance is same for both water ways and land ways. The aim is to find which would be needing lesser Fuel, if both are travelling with same speed:

Considering real life scenarios, like considering friction on land and turbulence in water.

  • $\begingroup$ Which do you have more of waterways or motorways? And what about turbulence on land? $\endgroup$
    – Solar Mike
    Commented May 5, 2022 at 18:06
  • 1
    $\begingroup$ If you consider cost to reflect efficiency, then the answer is ships. That's why China ships freight via sea even to Europe. Even in the days of sail, trade by sea between East and West was favourable enough over land that they would consider sailing around the Cape of Good Hope which is quite dangerous. $\endgroup$
    – DKNguyen
    Commented May 5, 2022 at 18:30
  • $\begingroup$ This must be easy to look up: Ocean ship, inland water barge, pipeline, rail, poor last -truck. That is for oil , but package freight will be similar. Did not consider air for oil but likely near truck depending on distance, weight, quantity, etc. $\endgroup$ Commented May 5, 2022 at 18:31
  • $\begingroup$ Search EEDI. Energy Efficient Design Index is a ship construction calculation of grams of CO2 produced per tonne, nautical mile. Ships are more efficient than trucks or trains. $\endgroup$ Commented May 5, 2022 at 18:38
  • $\begingroup$ @StainlessSteelRat but distance is a factor, try loading a cargo ship for a 10 mile trip between two ports... conversely using trucks to go halfway around the world... horses for courses as they say. $\endgroup$
    – Solar Mike
    Commented May 5, 2022 at 19:22

2 Answers 2


From the European Environment Agency - Rail and Waterborne cited in Jon Arnt's answer:

enter image description here

Chart shows gm CO2 / tonne km.

For my preceived interpretation of the question. The best way to ship cargo on land would be rail at 24 gm, then Inland WaterWays at 33gm, which are significantly better than heavy goods vehicles at 137gm.

But for shear mass of cargo the best way is via ships. 7gm would correspond to container ships.

From EEDI Explained enter image description here

Even generic cargo vessels >400 gt produce less than 30 gm CO2 / tonne nautical mi. 1 nautical mi = 1.852 kms. Larger the vessel the less polution is produced per tonne of cargo.

Carbon Calculator Emission Factors from CN (Canadian National) railway report: 2.5-6 gm CO2e/tonne-km for bulk carriers; 8.3 gm CO2e/tonne-km for containerships; 12.1 gm CO2e/tonne-km for rail; and 63.4 gm CO2e/tonne-km for trucks.

If there is a water path, cargo transport consumes significantly less fuel than a road path.


Unfortunately, this question shares multiple similarties to the phrase "How long is a fish?"; meaning that the answer is very dependent on the assumptions, limitations and scope of your question. I will for this reason not aim to give you an explicit answer to your question, but rather inspire you to narrow it down and hence hopefully bringing you closer to what you are seeking.

  • In your question, you mention details such as "turbulence" and "friction", suggesting to me that you are thinking of a hypothetical race between a car and a vessel over an equal distance. However, this introduces follow-up questions such as; what tires are the car using, what is the hull shape of the vessel or what is the weather at the time of this race?
  • You also mention in your question that "same caliber engines are used", but in what regard, seeing as marine engines are not built to be used in the same way as car engines? E.g., should they have the same power output, the same fuel efficiency, or...? Should they both use the same type of fuel?
  • What are you transporting, and why are you transporting it? Is the objective to get from $A$ to $B$ as fast as possible, or does it matter how comfortable the journey is? Are you transporting people, bananas, oil or simply yourself?
  • ...

The list goes on and on, but hopefully these initial thoughts will encourage you to come up with more follow-up questions yourself.

When you have a clear understanding of what you really are asking, then you may start searching for the correct answers. For example:

Best of luck!

  • $\begingroup$ the question is like "Which is faster swimmer Dolphin or Shark?". Out of two transport mode waterways vs roadways which will be better in terms of Fuel efficiency. Considering they both have same power engine, same fuel, same size and weight and whatever same is required to compare them on basis of "Firction offered by road vs Friction/turbulance of water". $\endgroup$ Commented May 6, 2022 at 8:31
  • 2
    $\begingroup$ If you are asking about the friction of water, I will suggest the following thread on the SE Physics page. Otherwise, I will recommend you to give some more thought to the steps in my answer above. A vehicle and a vessel will never have the same weight/power/size/etc. all at once, so you should rather state a base objective to compare fuel efficiency for. For example, race from London to Edinburgh or transport a 1 tonne cargo load from Hong Kong to New York. $\endgroup$
    – ToxicOwl
    Commented May 6, 2022 at 8:55

Not the answer you're looking for? Browse other questions tagged or ask your own question.