Why waste money on an outboard? The Marinediesel VGT Series makes them obsolete!

Outboard engines are usually a complete waste of money for commercial and government vessels.


Quite simply, they are not designed for anything other than recreational, or occasionally, racing use.

Outboard engines are usually merely petrol car engines turned vertically and connected to a modified automobile transmission. They were designed to provide the torque that an automobile requires in order to operate efficiently. The problems start to arise with respect to torque: Boats are under far higher levels of resistance than automobiles, particular at lower rpm ranges. So, many companies have tried to use diesel engines in outboards, rather than gasoline engines. What was the problem? Simple. The gearbox and drive systems were not designed to withstand the amount of torque produced by a diesel.

There is an old saying in the marine industry: “Horsepower sells boats, but torque actually moves them”. A quick glance at the marketing materials produced by outboard manufacturers quickly confirms that fact: Virtually none of them mention torque or show torque curves.

Some advantages of a diesel inboard over gasoline outboards:

  1. Diesel fuel is normally cheaper than gasoline in most markets. For example, in Australia, August 2015, retail price of diesel is A$1.29 per liter average, petrol A$1.34. In some countries the differential exceeds 20%. For instance, during the same period in Thailand, diesel averaged US$0.64 per liter and petrol US$0.93.
  2. Diesel engines always consume less fuel than gasoline engines. For instance, a Mercury Verado 350 consumes a whopping 353 g/kWh at full throttle, compared to 221 g/kWh on the Marinediesel VGT300. This equates to over 1/3 higher consumption. At cruising speed of 5,000 rpm on the outboard, the fuel consumption drops to 190 g/kWh, but the power produced decreases by over 1/3, netting just over 220 hp. The VGT300’s cruising speed of 2,800 rpm yields a fuel consumption of 195 g/kWh, but still producing nearly 280 hp.
  3.  As far as torque is concerned, virtually no comparison is possible. The outboard produces barely 400 Nm of torque, under a drastic bell curve, whereas the VGT 300 produces nearly 600 Nm of torque along the majority of the rpm range. A huge difference in actual work performed by the engine.
  4. Gasoline outboards have a MTBO of under 400 hours, light recreational use (all of them). A diesel inboard will last up to 3,000 hours MTBO. You could overhaul an outboard five times before needing to overhaul the diesel.
  5. The outboards are lighter. 303 kg versus 515 kg. This is reflected in their lower torque produced.
  6. However, space is less of a constraint. The Mercury Verado 350 is less than 100 mm smaller on all dimensions. A quick look at the photo above shows a transom width of about 1 meter. The VGT engines will require approximately 300 mm more length, and no extra width. A mere 300 mm extra height is necessary. In other words, on the boat picture, two VGT engines WILL fit.
  7. Outboards cost less to purchase. MSRP on the Mercury Verado 350 was US$32,000 in August 2015. The VGT 350 MSRP was US$37,000. However, given the fuel cost and consumption differentials, this small difference in acquisition cost quickly disappears.
  8. Gasoline is far more explosive than diesel. The inboards are much safer.
  9. Diesel engines have higher maintenance costs, but require much less maintenance.

As is evident in the points above, a strong case can be made for equipping your vessel with the Marinediesel VGT Series instead of outboards. The cost differential at acquisition is minimal, and the diesels far outperform outboards in nearly every instance. In particular, on the higher horsepower outboards, the price differential starts becoming significantly less.

Finally, in the picture above, twin Yamaha 200 hp outboards are pictured. A single VGT 400 or VGT 450 will outperform those two engines, lessening the price differential, even after gearboxes and drives are taken into account on the VGT engines.



VGT: THE diesel alternative to outboards

Outboards are common on small, high speed craft. Indeed, on some vessel types, they are often though of as the “default” propulsion method.


  1. They are cheap.
  2. They are easy to maintain.
  3. They provide “pretty good” speed.
  4. They do not take up much space.
  5. They are lightweight.
  6. A row of them, side-by-side “looks” fast and impressive.

However, outboard engines have some serious disadvantages and limitations:

  1. Outboard engines are usually gasoline automobile engines that are mounted vertically to a gearbox and drive system as a single unit. The forces generated by these engines are vertical, rather than horizontal, resulting in a substantial loss of power and a drastic increase in wear.
  2. Gasoline (petrol) is an explosion and fire risk, especially with government vessels or those used in the offshore industry. (Diesel is a much safer fuel)
  3. Gasoline is usually more expensive than diesel. Additionally, gasoline engines always consume fuel at a higher rate than diesel engines. (In some markets, the differential is as much as 50%).
  4. Outboard engines have a life cycle that is usually no more than a few hundred hours, at best. (You can  easily replace an outboard five times before needing to rebuild a VGT engine… Not so cheap now, eh?)
  5. Outboard engines are, by their design, limited in the number of propulsion options (You get what you get. With a VGT engine, you can use jets, surface drives, a variety of stern drives, or traditional shafts.)
  6. Diesel engines provide far more torque than outboard engines (Outboards cannot even come close).
  7. The vessel will always perform better with a VGT engine and proper propulsion system. ALWAYS.

The Marinediesel VGT Series of engines was designed to be the lightest, most powerful engines in their class. Our compact size and high power output make them an ideal alternative to the use of outboard engines. The VGT will, quite simply, fit where other engines may not.

Vessels can be equipped with Marinediesel inboard VGT engines at only a slightly higher cost than equipping the same vessel with large outboard engines, and that slightly higher cost is recouped very quickly in a much longer service life and the substantial fuel savings received. In fact, on larger outboard vessels, the use of outboards for propulsion is often equated by simply flushing money down the drain. They always cost more in the long term. In fact, many of our customers refer to outboards as “throwaway” engines. They run them full throttle until they simply break, and replace them with a new engine.


This “ease of replacement” and “ease of repair” is very much an illusion. The Marinediesel VGT Series will last up to five times longer than the average outboard before requiring an overhaul. Additionally, our remote mounting options give the VGT Series an ease of maintenance that approaches even the best designed outboard.

Additionally, the higher power and torque give a much better level of performance and control than an outboard-equipped vessel. Outboards, by design, are limited in the amount of operational control that they can provide, particularly regarding trim. A well-designed propulsion package with inboard engines will give a higher level of control and speed than even the best outboards on the market.

Finally, outboard engines are external, and thus, noisy by design. They are very difficult to control noise, and are often impossible for effective noise control.

If you want to look into the feasibility of using our VGT engines instead of outboards, and experiencing the meaning of true performance, Contact Us or your local Marinediesel Distributor for a quote today.


MarineDiesel Services Profile: Engine Installation and Commissioning


Today’s article continues our series profiling MarineDiesel’s various services.

Engine Installation and Commissioning

MarineDiesel understands that when we sell an engine, we often need to be the ones who install and commission that engine. Most commercial shipyards are perfectly competent to install an engine, yet, particularly on new projects, factory installation is desirable. It is also important to note that all MarineDiesel distributors are fully trained in engine installation and can perform these services locally.

One of the most critical tasks related to the reliability of  the entire propulsion system is the installation of engine and drive system. This can be performed by the operator, boat builder or the local Marinediesel representative, but it can also be performed by Marinediesel factory engineers on site anywhere in the world.
MarineDiesel factory engineers provide first grade quality service,  as well as reducing  the risk of breakdowns and stoppages related to poor installation. It can also allow for time to train local technicians on installations, thus, for the future, enhancing the skill and know-how level of the operator’s or boat builder’s own staff.
A professional installation  not only assures smooth  operation, but it also reduces operational  costs. In this context, prolonging engine  life  and  maintaining  operational efficiency are key objectives that are addressed by this program.
Marinediesel  can also supply a full project management service, supported  by expert personnel  and by a global back-up service. All this is targeted at the goal of providing the operator with complete confidence that the engines will run efficiently with excellent long term service.
Quality based , cost effective service delivered by factory engineers
Opportunity for the transfer of technology and know how.
Operational costs minimized due to reduced risk of breakdowns and stoppages related to poor installation
Expert project management
Peace of mind with full OEM warranty

The  quality workmanship of the propulsion system installation is verifìed and signed off during the commissioning. Our  fìeld  service  engineers  are  uniquely experienced   in commissioning engines,  and  will ensure  that  every aspect of their  performance is fully tested  and  optimized before handover. This includes auxiliary equipment such as transmissions  and drive systems in liaising with other suppliers when necessary to ensure that every part of the installation functions correctly. Commissioning can be performed by Marinediesel fìeld service  engineers  on  site  anywhere  in the world. The  commissioning sign-off is also required  for warranty to take effect.



MarineDiesel Services Profile: Factory Express Service



Today’s article continues our series highlighting the services MarineDiesel offers its’ customers.

We offer Factory Express Service to all MarineDiesel customers.

Express service Worldwide

Marinediesel understands the costs of vessel downtime and has responded to this with the FES program. Not only do we provide a comprehensive range of services and technical support for all Marinediesel products worldwide on land or at sea but the FES adds the fast response requirement of some clients.

FES field engineers can be mobilised to sites anywhere in the world within a very short timeframe. FES engineers can perform the task independently or act as supervisors for local staff where required. Capabilities within the FES-team is vast including capability to perform torsional analysis in vessel, logging equipment for mechanical and electronic engines, power tests in vessel to mention a very few. Marinediesel is unique in supplying this service for the particular power range.

Key benefits:

» Skilled engineers available Worldwide
» Cost effective compared to cost of downtime
» On-site supervision of local staff reduces cost
» Express Service
» Full OEM technical backup

Contact your local MarineDiesel dealer or distributor today for complete details.



MarineDiesel Services Profile – Factory Replacement Program


Today’s article starts a short series of articles highlighting the various services that MarineDiesel offers to its’ customers.

Over 80% of MarineDiesel customers are commercial or government users. Customers whose engines typically operate every single day, under the harshest of environmental and operational conditions. These types of applications cost customers serious money when engines break down or otherwise experience mechanical problems.

That is why MarineDiesel developed its’ Factory Replacement Program, or FRP.


Marinediesel as a company has always looked at ways to assist clients and operators in meeting their long term targets. In this progress Marinediesel has developed the FRP or factory Replacement Program which allows
the operator to get first grade quality service as well as reducing and scheduling operational costs. In this context, prolonging engine life and maintaining operational efficiency are key objectives which are addressed by the program.
Marinediesel, as the OEM manufacturer of the engine, has the in-depth knowledge and experience required for quality overhauls. Every aspect of our service is based on rigorous quality standards and supported by top-level
technical expertise at Marinediesels modern facilities. The FRP allows the operator to have a fixed cost per hour that includes replacement engine at TBO-time. Please contact Marinediesel direct or your local representative for further information. The FRP is available for all Marinediesel products.
As a part of the program we work closely with our operators to ensure that maintenance tasks are scheduled to minimize downtime and optimize engine running hours.

» Quality-based, cost effective service delivered to highest OEM standards
» Technical support and problem solving advice from highly experienced engineers
» Operations maintained at optimum levels with efficient turn-around
» Engine performance thoroughly tested thus avoiding any delays in operation
» Flexible, customer-focused programs


Ängelholm is the world headquarters for Marinediesel and the entire MD Group, and it is here that engines
are overhauled under the FRP program. These facilities include:
» Large workshop for teardown, cleaning, inspection and assembly
» 3 top of the line test cells dedicated for the program
» 2 hot test cells
» In-house environmentally controlled paint shop providing highest quality finishing
» Commissioning and on-site service support packages
» In-house R&D and engineering-lab department for any QA or material inspections required
» Full torsional vibration analysis equipment
» Dedicated sub-assembly areas to ensure cleanliness and highest quality assembly
» Full inventory of all parts

» MD200
» MD250SC
» MD300SC
» MD-VGT350
» MD-VGT400
» MD-VGT450
» MD-VGT500

Contact your local MarineDiesel dealer today for complete details on our FRP program and how it can help you minimize downtime.





Best of 2014 – Industrial Engine Week, Airboats



We wish all MarineDiesel customers a happy holiday season. Our factory will close from December 22 through January 5. For the balance of the year, we will be re-running our most popular articles from 2014, based on the number of visitors. We will start new daily articles in the New Year. We hope that you continue to find them interesting.

Today is the final day of our industrial engine week, and we focus on a niche market that has been up-and-coming for MDPT over the last couple of years: Airboats. Hmmm…


Correct. Airboats are a special case that is handled by MDPT rather than the larger MarineDiesel group because airboats are a hybrid of sorts. They are boats, but they use engines that are engineered for use on land. This makes them unique in the marine world.

Traditionally, airboats were simple vehicles: A shallow, flat bottomed boat with a (usually) used aircraft engine mounted astern that featured a direct coupling to an aircraft propeller straight off the flywheel. Ratios were inexact, with propeller pitch largely used to control performance levels.

Modern airboats bear little more than a casual resemblance to these old vessels. Modern airboats can now be equipped with climate controlled cabins, gun positions for military use, and are always equipped with modern, compact and high powered engines. Propellers are designed with lightweight composites, and there are complex gear or belt drive systems that can include variable gear ratios. Indeed, some airboats are now equipped with contra-rotating dual props that provide huge amounts of torque and extremely high speeds.

Airboats are often commonly seen in the Everglades, or on TV shows like “Swamp People”, and so on. They handle conditions in swamps quite well, being shallow draft and not having any propeller to run aground or get snagged. However, there are many other applications for airboats, and this niche market is booming: Military use for patrol, rescue, use on ice. All of these uses are now common.

For more information:

Leppek, Adam P., “Optimization of an Airboat Design” (2012). Honors Theses. Paper 2180. offers a good and interesting overview of modern airboat design and why airboats are well suited for their application.

MDPT is at the forefront of powering some of these cutting-edge designs. Our marine heritage serves us well in providing specialized engines for airboats. As we mentioned earlier, airboats are a hybrid of sorts. They use engines designed for use on land, but they are exposed to the harsh marine environment. We have the ability to combine these two fields of expertise into a single, customized and application-specific product, with appropriate injectors, connectors, and cooling systems. We also work very closely with the drive manufacturers, propeller manufacturers, and designers to offer complete airboat propulsion packages.

We have completed airboat projects in Russia, Finland, the USA, Australia, and Thailand, and this market segment is becoming a specialty of MDPT. Contact us today on your next project, but please see below for some previous MDPT installations.

PantherDuramaxFinland AA 022012022??????????????????STAATSOLIE

10 Myths About Diesel



Yesterday’s article focused on 10 facts about diesel fuel and diesel engines. Today’s article will explore 10 common myths about diesel fuel and diesel engines. If you read or hear anything about the information below, just don’t believe it: It isn’t true:

  1. Diesel engines must idle a long time after starting. This is a statement that was once true, but no longer. Before common rail technology and modern electronic diesel engines existed, diesel engines needed to idle for a while both at startup and at shutdown. This was due to the nature of diesel combustion and the design of early turbochargers. Modern, electronic diesel engines do not require long warmup and cooldown times.
  2. You cannot use synthetic oil in a diesel engine. Pure hogwash. In fact, the recommended oil in MarineDiesel’s VGT Series of engines is synthetic. Why? It has a longer life cycle and resists higher temperatures and thermal breakdown better.
  3. Diesel engines are noisy. Again, this used to be true, but no longer. Though modern diesel engines can produce slightly more noise than gasoline engines, most manufacturers have greatly reduced the amount of noise produced. This is one area where MarineDiesel has put significant resources into R&D.
  4. Diesel’s don’t start well in cold weather. Not true. Inexpensive inline heaters are standard on modern diesel engines and they start just as easily as other engines in cold weather, sometimes better. Note, we are well-versed in cold weather operation, given our Scandinavian heritage. Our customers use our engines in some of the coldest climates on Earth, including Greenland and Russia, without problems.
  5. Turbochargers lag. Again, not true. There is a reason that we use VGT (Variable Geometry Turbocharger) turbochargers on our engines.
  6. Diesel fuel is dirty. Not true. As mentioned in yesterday’s article, ULSD is one of the cleanest fuels.
  7. Adding propane gives diesel a boost in power. False. Don’t. Ever. Do. This.
  8. Diesel maintenance is expensive. All marine engines require maintenance. Generally, over the life cycle of the engine, diesel engines are cheaper due to the longer life cycle. Maintaining filters, gaskets, and keeping to the maintenance schedule as detailed in your manual keep diesels running trouble free over the long term, often cheaper than other types of engines.
  9. Diesel engines are sluggish. Not true. Modern ECUs produce efficient combustion. The higher torque of a diesel means a much quicker response than with petrol.
  10. Most engine wear on marine diesel engines occurs when operating at WOT. Not true. Most wear occurs at startup with rapid increases in throttle.


10 Facts About Diesel



There are many myths and misconceptions in the marketplace regarding diesel fuel and diesel engines. Indeed, the debates can be endless, and every engineer and naval architect has their own beliefs. Some may be true, while others are no more than mere wive’s tales. Today’s article discusses some interesting facts about diesel fuel and diesel engines. Tomorrow’s article will address some of the myths.

  1. Diesel fuel was named after the diesel engine. NOT the man who invented the engine (Rudolf Diesel)
  2. Diesel fuel, unless further refined, is a high pollution fuel. Further refining, under emissions regulations, has produced Ultra Low Sulphur Diesel (ULSD), which is one of the cleanest fuels in the market. Thus, modern diesel fuel is usually cleaner than the gasoline with which it is often compared.
  3. Diesel engines are always more fuel efficient than gasoline (petrol) engines.
  4. Diesel does not evaporate (as does gasoline), but it does degrade more quickly over time.
  5. Diesel engines are more durable and have a longer life span than gasoline engines.
  6. Diesel engines require more maintenance in the marine environment than gasoline engines.
  7. Diesel engines tend to be more expensive at purchase than gasoline engines (though the longer life cycle means that they are usually cheaper over the long term).
  8. Diesel engines produce more heat than gasoline engines. The nature of diesel fuel means that it has a BTU output, and thus produces more heat.
  9. Diesel fuel is usually the same price or cheaper (even ULSD) than gasoline at the refinery. The price differentials are usually more related to local taxation, rather than the cost of production.
  10. Biodiesel is still diesel. Though it is refined from vegetable products, rather than petroleum, biodiesel still must meet strict standards for quality and energy content. Nearly all marine engine manufacturers allow the use of biodiesel within their warranties.




5 Reasons to Re-Power your Boat



Engines lose performance as they age. Either from heavy use, environmental conditions, or even through the lack of use. Cylinders can become grooved, seals and gaskets become worn, and the engine is no longer providing the performance it once gave. This situation is not only with marine engines. Though marine engines operate under much harsher conditions than industrial engines or engines in land vehicles, those engines eventually also wear out and need replacement. This article is not so much related to replacing worn out engines. The rebuild versus re-power argument usually comes down to cost, and sometimes feasibility (Engines can only be rebuilt so many times).

What if you have an engine that is still functioning? Are there reasons to consider re-powering before the end of that life cycle?


Here are five reasons:

  1. Fuel Efficiency: We were recently involved in a project that was asking us to perform a cost / benefit analysis on re-powering some vehicles equipped with some old Cummins engines. Though these engines still operated, and were quite fuel efficient when they were manufactured (around 1990), re-powering with modern, MarineDiesel engines could save the customer almost 20% in fuel savings over the course of one year. Technology changes, and engines have become far more efficient in the last 20 years. Even though rebuilding the existing engines would be cheaper, the fuel savings over the long term more than make up for the additional acquisition cost.
  2. Emissions:  Emissions regulations have become extremely strict, especially in North America, Europe, and the Polar regions. Old engines were manufactured under different emissions regulations. What was once compliant is now non-compliant.
  3. Performance: As engine efficiency has increased, engines are now lighter and more powerful than ever. New engines nearly always show increases in vessel performance over rebuilt old engines.
  4. Vibration and Noise: As engines wear, they tend to vibrate more, offering a reduced life cycle over time. Additionally, the standards for vibration and, particularly, noise have changed over time. Modern engines are far quieter and produce less vibration than rebuilt engines.
  5. Cost of Maintenance: Every time an engine is rebuilt, a little of the life cycle goes with it. Though engines can be rebuilt to a very high degree of competence, they are still older engines with a significant level of use. Maintenance expenses will always increase. Perhaps not by much, but they will increase nonetheless. Add in the fact that, on average, the cost of rebuilding an engine averages 60% of its’ cost new. Extra maintenance expenses can quickly close the gap between new / rebuilt.





Engine Market Insights: USA



Today’s interview is with Mr. Malcolm Phillips, CEO of Performance Diesel, Inc., MarineDiesel’s distributors in the United States and North America.

united-states-of-america USA

Performance Diesel Inc.

12130 Galveston Rd
77598 Webster, TX
Phone: +1 281-464-2345
Mail: mphillips@performancediesel.com
  1. How long have you been in business in the USA?

Since 1985

2. What is your company’s mission and goals?

Our mission is to provide the highest quality of service to our customers in the marine and industrial diesel engine markets. We represent quality products made by quality manufacturers. Our continued success can be attributed to the outstanding service and support we provide for the products we supply our customers. We will remain committed to customer satisfaction and continue to uphold the highest degree of integrity and professionalism while achieving market share and corporate goals.

  1. What makes Performance Diesel unique? (Services offered, capabilities, etc.)

We are a Self Proprietorship which allows for decisions to be made quickly. Therefore, if issues arise, we react swiftly in order to satisfy of customers needs.

Our two main packaging and manufacturing management staff have more than 50 years of experience together, and our production and manufacturing staff are with us for over 10 years. Therefore, we have well trained employees who are capable of getting the job done in the shortest time as possible.

Our service staff is highly trained, and are able to correct any issues in the field, overseas and in our shop, in short order.

Our COO has been a key part of our success and knows our operation inside and out. Mr Brent Wagner has been with the company for over 20 years.

Our sales staff are not only trained in sales, but have come from the service side of our company, which is critical from the owners perspective as our expertise is making sure that we sell the right product for the application.

Our owner has been in the Diesel Engine Service and manufacturing business since 1974 and continues to be directly involved with our customers and core business.

Performance Diesel Inc is capable of assisting our customers will all of there engineering and installation needs as we are both 2D and 3D capable.

  1. In addition to MarineDiesel, what are your other major product lines?

MAN Engines and Components, Hyundai SeasAll marine engines, ZF marine transmissions, Castoldi Waterjets, Northern Lights Gen sets and PDI custom generator sets.

  1. What is the engine market like in the USA?

We have been struggling for the last 4 to 5 years, however this spring we have seen activity on the Custom Pleasure-craft side of our business starting at 50 feet to 60 feet class boats.

We continue to see weakness with production builders. And the stern drive sector has more or less been taken over by outboards. Outboards are now powering the vast majority of boats sizes from 20′ to 40′ in the US.

Military and commercial business also continues to be weak due to budget cutbacks, though we just began a small government order of five shipsets.

  1. What are your greatest challenges in the engine market?

The US owners do not use their pleasure craft as much as other countries, therefore, the need for diesel power is less. Gasoline power remains a choice, and will until gas engine prices increase and the cost of gasoline becomes similar to the cost of Diesel. One other issue is the availability of diesel fuel around our inland lakes.

  1. Where are the greatest opportunities in the engine market in the USA?

I can’t pinpoint one great opportunity. Business today requires attention to all opportunities from pleasure craft to commercial and military in order to survive.

  1. How do you see the engine market in the USA in the next five years?

We are seeing a small increase in 45′ to 58′ class pleasure craft. The larger pleasure craft sales in the custom boat market remain strong, but this market is less than 100 boats per year with horsepower ranging from 2 x 1800 hp to 2 x 2800 hp.

Small production builders continue to show low numbers, and is a market of only a few thousands boats rather than more than 10,000 boats per year, and outboards are dominating this market.

We are hoping that the US military budget will increase as we understand that there is a need for new vessels, however requirements for these new vessels are asking for outboard power.

During my travels to Europe I hear and see the same issues that we are experiencing in the US. With current sales staff and our dealer network, we hope to capitalize on every opportunity possible. We firmly believe that we have superior products to offer, however we continue to deal with ferocious competition when it come to cost and end pricing. In order to increase sales over the next five years, we must continue to find ways to lower cost and to provide the best product possible. We do not expect to see a big recovery within the next five years. However, we do expect to see opportunities increase by 10 to 20 percent per year over the next 5 years.