It is a question confronting more and more new generator buyer. Whether you opt for the more expensive diesel engine may hinge on your experience with diesel engines. Perhaps it will depend on your desire for performance. Or maybe your decision will be based largely on economics, but chances are there will be an emotional element to the decision too.
For most new generator buyers, diesel engines connote power — the power to move or pull heavy loads. The terms “strength”, “heavy-duty”, “durable”, and “rugged” are all associated with diesel. Power — that’s part of the emotional appeal of diesel. After all, you don’t think of diesel engines for light-duty applications like motorcycles or lawnmowers. You may not even think of diesel as appropriate for automobiles, but that too is changing.
It’s also possible that most of your impressions of diesels have been less than favorable. If you’re like most folks, your past experience with diesels may be mostly with big trucks and buses. At one time or another, everyone has been stuck behind a particularly smoky (and stinky) bus or big rig truck. That big diesel-powered behemoth was probably slow too. Fortunately, those old, slow, and dirty diesels are disappearing from the scene. Such diesel engines, especially those of a couple of years ago, don’t necessarily have much in common with the smaller diesels used in today’s pickups, SUVs, and motor homes, but they have been part of shaping public thinking. The chances are that your diesel perceptions are based largely on past diesel technology because the new generation of modern diesel engines has only been around for a few years, and the changes have been dramatic. In fact, almost all of the objections people once had to diesel engines have now been eliminated. That might seem like a lot believe, so let’s take a look at some of the specifics.
Modern diesel engines now have computerized engine management to control electronic fuel injectors that operate at incredibly high speed and pressures. What this means is that the right amount of fuel is injected at the best possible time for optimum combustion efficiency with minimal pollution and virtually no smoke. That’s right, smoke is a thing of the past. And now that smoke is gone, so is almost all diesel exhaust odor. What little diesel exhaust aroma remains will be gone when ultra-low-sulfur diesel fuel replaces current diesel fuel in 2006, as mandated by the EPA.
The next thing you’ll notice about modern diesel engines is that they are quiet. Gone is the clattering sound that some made at low speeds.
Pilot injection is an ingenious noise suppression cycle for modern direct injection diesel. Modern diesel with pilot injection run almost as quietly as comparable gasoline engines.
The last common objection to diesel engines, other than the initial cost, is the availability of diesel fuel. Happily, more and more gas stations have added one or more diesel fuel pumps, so filling up no longer requires a mandatory trip to a truck stop. Diesel fuel prices are typically close to that of regular grade gasoline, but that depends on availability, where you live, and local taxes.
Having covered the common objections to diesels, it’s time to look at a few of the advantages. One of the biggest advantages is fuel economy. Diesel engines typically deliver 20- to 40-percent better fuel efficiency than comparable gasoline engines doing the same amount of work. Depending on how many hours you use your generator a year the cost of fuel, this can amount to a substantial saving that offsets the cost of the diesel option over the life of the generator.
There are other less obvious benefits from having a diesel engine. Diesel engines are available with turbochargers. As well as adding efficiency to a diesel engine, a turbocharger also has the advantage of offsetting power losses when a generator is operated at higher altitudes. If you live at high altitude, of if you will use your generator at locations at high altitude, a turbo diesel makes a lot of sense.
Another advantage of owning a diesel engine is you can make your fuel using used vegetable oil for example. You can not do this with a gasoline engine. Diesel fuel has a much higher flashpoint than gasoline, so it is not as dangerous to store. It also lasts twice as long as gasoline.
So what are the advantages to selecting a gasoline engine? Aside from slightly lower initial cost, there’s little to recommend gasoline engines today. It’s a new world, and diesel is no longer the fuel of the future — it’s the fuel (and the engine) for today.