Gas Versus Diesel - RV's

This article discusses an age old question and one I get asked a lot, should I buy gas or diesel? This question has fueled many a heated debates too. Sometimes this question involves a truck that will be used to tow a trailer, and other times it involves what type of motorhome to purchase. A universal response you could expect to hear to this question goes something like this: Diesels cost more. Don’t buy a diesel unless you plan to put a bunch of miles on it and keep it for a long time. That’s the only way you can justify the extra cost of a diesel.

Several years ago there was some truth to this somewhat typical response. But things are changing, especially when you’re talking about motorhomes. Today, the cost of some gasoline powered motorhomes is about the same as many of the entry level diesel motorhomes available on the market. This higher cost is mainly due to advancements in gasoline RV chassis’ design; with greater Gross Vehicle Weight Ratings (GVWR) to accommodate coach designs with 3 and 4 slideouts. And don’t forget to factor in the new technology in gasoline engine and transmission design over the past several years.

The old response, of diesels costing more, does hold true with some of the specialized diesel chassis manufacturers, but it’s not just the engine that accounts for these higher prices. You are moving to a much higher plateau across the board. For the most part gasoline RV chassis’ are heavy duty truck chassis’ modified for Recreation Vehicle use, whereas many diesel chassis’ are a bus chassis. These bus chassis’ have even greater GVWR’s, air brakes, air ride suspension systems, larger transmissions, rear mounted diesel engines and more. They handle better, ride better and cost more. I always say you get what you pay for.

Other than the cost factor between gas and diesel motorhomes, what are we really talking about when it comes down to gas versus diesel? Say for example in a truck you want to use to pull a trailer. This is where we need to factor in the engine itself. This is also where torque and horsepower come into the equation.

Explaining torque and horsepower can get extremely technical, and we want to keep this simple and easy to understand. With that said, torque is basically the force or energy required to move something. Torque is the measurement of force, and force is measured in reference to a twisting or rotating shaft. In English terms torque is measured in pounds-feet, but is more commonly referred to as foot-pounds. So in keeping it simple let’s just say that torque can be thought of as the amount of turning force it takes to move one pound of weight the distance of one foot.

Torque can be multiplied through gear ratios. You have probably heard that the higher the real axle gear ratio is the better the truck will tow. The axle ratio is the number of times the driveshaft must rotate to turn the rear wheels one time. If you have a 3.73:1 axle ratio the drive shaft turns 3.73 times for each full turn of the axle. So in a sense torque really equals towing capacity.

Horsepower on the other hand is torque X RPM’s. Torque is how much work is being done, and horsepower is how fast you get the actual work done. What’s interesting is an engine rated at 350 horsepower only produces that horsepower at a rated peak power RPM. This RPM range, for a gasoline engine, is often between 5,000 and 6,000 RPM’s. When an engine is idling the horsepower is significantly lower, and as the RPM’s raise so does the horsepower. When you are towing a trailer the engine speed is more likely to be in the low to mid 2,000 RPM range, which means you probably have slightly more than half of the rated horsepower. Horsepower is measured by a dynamometer. A dynamometer puts a load on the engine and measures the amount of power the engine produces against the load at various speeds. In reality it is measuring torque in pound-feet and converting it to horsepower. Even at the rated peak power RPM you won’t really get the rated horsepower because a percentage is lost through auxiliary equipment on the engine and the process of getting it back to the wheels.

In a diesel engine the horsepower peaks at a lower RPM, and there is more torque at a lower RPM compared to a gasoline engine. This results in a diesel engine having much more power at a lower RPM, around the RPM range you will be towing at. This higher torque and higher horsepower at a lower RPM equates to better towing.

There are many other factors involved in the question of gas versus diesel that you will need to consider. What are the maintenance costs involved, cost difference between fuel types, fuel economy, your budget, and the resale value? Whether it’s for a tow vehicle or a motorhome, take your time and make a well informed decision when comparing gas to diesel.

If the question is which truck will tow more or which motorhome has more torque the diesel will win hands down, but I honestly have no complaints with our gas powered motorhome either. Especially when considering the price.

Q&A

Question: Why does a diesel engine have more torque?

Mark Says: Much of the reason is in the way the engine is designed. Internal combustion engines use spark from a spark plug to ignite fuel in the combustion chamber of a gasoline engine and the high heat from compression to ignite the fuel in a diesel engine. It’s more difficult to burn diesel fuel so diesel engines have higher compression ratios resulting in more heat to ignite the fuel and more power.

Question: I have always heard that a diesel engine is much louder than a gas engine, is this true?

Mark Says: If you asked me that several years ago the answer would have been yes, but newer diesel engines are actually very quiet.

Question: You said in the article a diesel motorhome rides better, why is that?

Mark Says: Most gas motorhome chassis’ use leaf spring suspension systems. With this suspension system you will experience things like “body roll” and “pitch.” whenever pressure is exerted against one side of the motorhome. It can be caused by a gust of wind, a shift in weight while cornering, or a passing truck. The effects of sway on a motorhome are increased because of the height and mass of the motorhome. A diesel chassis uses an air ride suspension system. These systems keep the chassis adjusted to the proper ride height at all times by adding and releasing air as required. And the way the system is designed eliminates the pitch and roll affect you get from leaf spring suspensions, resulting in a smoother riding motorhome.

Diesel Engines: Tap the Advantage!

If you own a diesel powered vehicle, you probably appreciate the inherent qualities of this type of engine. More torque, better fuel economy, easier maintenance are some of the attributes of owning a diesel powered vehicle. Still, some motorists complain about the engine’s weak power, particularly when accelerating from a full stop. What you may not know is that a diesel engine can be tweaked to produce more power without harming fuel economy. Let’s take a look at diesel engines and what you can do to squeeze out more power.

Thanks to the work of one man, Rudolf Diesel, we have a choice when it comes to driving. Besides hybrid or rotary engines, the chief way most vehicles run is via a gasoline powered internal combustion engine. However, with Diesel’s 1892 patent of the engine that bears his name, diesel power has played a significant role in powering buses and trucks across North America. Some passenger vehicles, particularly pick up trucks, are also diesel powered giving motorists an option to gasoline.

Diesel engines have the following advantages over their gasoline counterparts:

Diesels use air compression to create combustion versus the air/fuel mixture required by gasoline powered cars. This attribute means that diesel engines do not require spark plugs and thus do not have to be tuned up.

Diesel fuel has a higher fuel density than gasoline resulting in fuel economy increases of 20-30% over comparable gasoline powered models.

Diesel engines are cheaper to maintain as they have less parts vs. a gasoline engine. The lifespan of a diesel engine is also significantly longer.

If it is torque you need, particularly for pulling a boat, camper, or equipment, than a diesel engine has the advantage. A diesel engine is definitely slower especially when starting from a dead stop, but when climbing hills or going over bridges, your diesel powered vehicle can definitely handle the challenge.

So, why aren’t more vehicles built in North America diesel powered? A few reasons including:

Stricter emissions control standards. Diesel engines pollute more, so not many manufacturers have improved upon the technology to produce an engine that is environmentally friendly. However, several upcoming engines from VW and others may change all of that.

Not enough power. Yes, a common complaint, even with turbo diesels, is that the engines are not powerful enough. North American drivers are accustomed to getting on the highway with a minimum amount of effort. With a diesel engine, it can take as much as twice as long to get up to full speed.

Fortunately, several aftermarket product developers are helping motorists squeeze out more power from their diesel engines. Performance programmers, made for specific diesel engines, are helping motorists see a nice spike in horsepower as well as increases in torque. The beauty of some of these aftermarket parts is that they don’t harm fuel economy. In fact, some claim to help improve it.

Yes, the number of diesel powered passenger vehicles presently on North American highways is presently very small; however with newer, cleaner and stronger engines on the way, you may soon find yourself opting for a diesel powered vehicle too.

Why Should You Choose A Diesel Engine For Your Truck

Often times, people decide to purchase a large truck to haul very heavy loads. If that is not your intention, and you'd like to purchase a truck to drive more like a car (with quick, quiet acceleration), you may want a gasoline engine.

There are three main benefits to this:

Gas engines run smoother
Fuel is easier to find
Gas engines start easier in cold weather

If, however, your intent is to use your truck for towing, you may want to consider a diesel engine.

The three main benefits to this are:

Good fuel economy
High mileage
Better for towing

Now, the price of a diesel truck is very high, but it very well may be worth it. They have many benefits, and could very well save you a good deal of money in the end. Benefits vary from manufacturer to manufacturer. You can compare these benefits below:

Ford

In 1994, Ford introduced its international engineered power stroke diesel. This pushed the 3/4 ton and 1 ton truck market to where it is today. Before this, the big one inch gasoline engines made these poorly built diesels barely considerable. Over 70% of super duty Fords were sold with the optional 7.3L V-8 diesel engine from 1994-2002. Because of this engine, Ford became one of the leaders in diesel trucks.

Dodge

In 2002, Ram didn't have enough power with the 245 HP 9.5L, so Dodge promised more powerful engines for the 2500/3500 platform, and they definitely followed through on their promise: the 2500 and 3500 Dodge Ram Heave Duty trucks are the newest ¾ and 1 ton trucks on the road.

The new base engine is the 5.7L gasoline V-8, which revives the well-known, historical Hemi name, as it is the most powerful engine of the group at 345 HP.

Chevrolet/GMC:

Coming standard with GM's 6.0L gas engine V-8 are the GM 2500/3500 twins Silverado HD and Sierra HD. The engine is ideal for ¾ ton trucks where towing isn't a concern. Based on Chevrolet's venerable big block engine are the upgrades that start with the 8.1 gas V-8.

Diesel trucks have proven to be:

Efficient with mileage
Great for towing
Easy on maintenance

Also, you won't need to get them tuned up nearly as much as gasoline engines, because-unlike gasoline engines-diesel engines do not have spark plugs.

If you need or want to haul heavy loads frequently, you should probably stick with diesel, since you can get better mileage (diesel trucks are built to go 250,000 miles more). Because of all these reasons, although diesel trucks tend to cost more, they will end up being well worth the money in the long run.

Diesel Versus Gasoline: Why a Diesel Powered Car Might be Your Better Choice

The word "Diesel" should no longer make you picture semi-trucks, or loud, clunky broken down cars. Diesel over the past twenty years has changed by leaps and bounds and has become more popular now than ever.

If you rode around in a diesel vehicle in the 80's, you are probably screaming "gasoline is better" at the top of your lungs. This is excusable due to the fact that twenty years ago diesels were extremely loud and unreliable. Luckily for us, technology has come to the rescue in the form of reliability. Diesel cars are now commonly seen running with over 250,000 miles of use. Though gasoline engines can hang in there for quite a long time themselves, getting to the quarter million point, with proper maintenance, is unlikely.

Life expectancy is definitely a plus when comparing diesel and gas cars. What about maintenance? Well, diesel engines don't use an ignition so you have no tune-up costs or worries. They use glow plugs rather than spark plugs which generally need to be changed every two years or so plus or minus a few months depending on the vehicle. As far as oil changes, they work the same as gas engines---change the oil every 3,000 miles and you'll be fine. Fuel and air filters should be changed regularly as needed, of course.

Now, the all important numbers. If we start with upfront costs, the diesel seems more expensive, and a comparison of the same make and model car yields a cost difference of about three thousand dollars between the diesel and gasoline versions. But is diesel really more expensive? Let's examine the question.

Diesel fuel is almost always cheaper than unleaded gas, and how much cheaper varies of course with rising and falling gas prices. But The cost savings do not stop at the pump; they continue as you drive down the road and by this we are talking fuel economy. The diesel is the king of this domain. With some diesels getting over 70 mpg, this is by far the best bang for the buck.

So the diesel wins in fuel economy and maintenance. But are there disadvantages to diesel? Well, diesel engines aren't perfect. They can be a little noisier than gas engines, though this small amount of noise usually fades at cruising speed. They also lack a bit in acceleration compared to gas engines.

However, despite these small shortcomings, diesels are certainly becoming more user friendly and more economical and each day more and more people are choosing to go this route. It's even quite possible that one day the majority of our motor vehicles will be diesel powered. However, until then you have the information needed to consider whether or not the diesel will be a contender for your next vehicle purchase.

Diesel vs Regular Gasoline - Which is Better for the Environment?

With the implementation of alternative fuel sources on the minds of many, diesel is now under the microscope more than ever. Although diesel-powered vehicles have been around for a long time, gasoline is still the primary fuel source for most North American vehicles. Why has diesel not been used as a fuel source in more vehicles? Which is better for the environment? These are questions that are being asked more frequently as the search for alternative fuels is weighing heavily on more people's minds.

Gasoline vs. Diesel

It turns out that gasoline is more volatile than diesel, not because of what its base consists of, but because of the additives it contains. In addition, vehicles that use diesel tend to be more fuel-efficient and produce less greenhouse gases. In that respect, diesel is more environmentally friendly. Diesel actually produces 15% more in greenhouse gases than gasoline when compared by the litre rather than the gallon. Yet it is through the 20-40% improvement in fuel economy over gasoline that offsets the higher emissions per litre. In actuality, the carbon dioxide emissions are considerably less than gasoline, but diesel does contain 2,778 grams of carbon per gallon, whereas gasoline contains 2,421 grams per gallon. But, again, it is the fuel economy of diesel that accounts for the smaller rate of carbon emissions.

Then again, diesel fuel contains larger quantities of sulfur. The United States has what is considered to be the dirtiest diesel, but as of June 1, 2010 this is going to be different. U.S. diesel fuel has a lower measure of ignition quality. This means that when it is cold outside, ignition performance is poor and can result in higher emissions. This is why you see truck drivers idling their trucks all night long in cold weather rather than risk a troublesome start in the mornings.

But, the sulfur in the diesel that is emitted during cold ignitions and long engine idling is still harmful to the environment because the sulfurs prevent the control of diesel particulate emissions through diesel particulate filters. This is changing, though, since new advanced technologies such as nitrogen oxide absorbers are being developed to reduce these emissions.

As for gasoline, it is the non-aliphatic hydrocarbons as well as carcinogenic additives that avoid engine-knocking that threaten the public's health and the environment. This exposure happens in the case of gasoline leaks and then, of course, there are the carbon emissions we hear a lot about. Leaks occur when trucks begin leaking the gasoline they are carrying, storage containers are not stored properly, and from motor vehicle leakage. The harmful additives in gasoline can get into groundwater and contaminate public water supplies.

However, Dieselization is becoming a more common use of diesel as a fuel in motor vehicles, although it is determined that both diesel and gasoline have harmful effects on the environment. When we look at the carbon emissions of both, we find that diesel will emit more per gallon (or litre), but when you look at how much you have to fill the fuel tank with diesel versus how much you have to fill with gasoline, you will find that the percentage of emissions is offset for diesel, which can be friendlier on the pocketbook. On the other hand, sulfur is emitted by diesel and diesel does not perform as well in cold weather as gasoline, so until 2010 when diesel is cleaned up, gasoline may be slightly more environmentally friendly than diesel in respect to the emissions from automobiles. As for ground contamination, diesel has an edge over gasoline in keeping our world clean.

Gas Versus Diesel

Buying a car is not as easy as listing down your specifications and having a car magically appear in front of you. Often times, you have to sacrifice some features in order to have other features. Remember, not everything can be found in one car. You have to study the features of each and prioritize the features that you cannot really do without. After all, you cannot have everything you want, unless of course, you have it custom-made.

When buying a car, one of the considerations that you have to look into is the fuel that you will be putting into the tank. There are two types of fuel that is being used nowadays, the diesel and the gas. To help you decide, here is a rundown of their characteristics, presented in a comparison format that you will find easy to read.

Safety

Diesels are actually safer than gasoline in terms of explosion. Gas tends to ignite but gasoline explosions are not as frequent as people want you to believe. In fact, gas explosions are actually quite rare. The last one happened some thirty years ago and no repeat incident has been seen so far. Statistics also state that it is more likely for persons to incur injuries in a plane accident than in a gasoline explosion.

Diesel on the other hand is not explosive by nature especiallu now that water-cooled turbochargers have been invented to prevent overheating.

In terms of carbon monoxide poisoning, gas is also more dangerous. Compared to gas engines, diesel-run engines produce less carbon monoxide. Rather it produces sulfur dioxide which although may cause nausea is not as life-threatening.

Price

Hands down, gas is more expensive than diesel in the world market. This is why it is much more economical to use diesel on your car because you can save a lot in terms of fuel cost. Costs balance out when maintenance costs come in the picture. This is because it is much more expensive to maintain an engine or car that run in diesel than in gas. Parts for diesel engines are more expensive and the rate for the mechanics that fix them are even higher.

In buying your car, make sure that you take this into consideration. If you do not plan to use your car for a very long time, it is better to stick to diesel but if you plan in keeping your car for decades, it is better to stick to the gas-type. Sticking to gas is also an option if you are the type who do not often use your car.

Long life

Diesel they say live longer than gas engines but when you count the number of times that you have to change a part, the costs that you incur is actually the same. Diesel engines seem to live longer because they are more maintained than gas engines. You really have to find the time to maintain your car and to really take good care of the engine. This is because diesel engines are more susceptible to corrosion.

Environment

One of the things why engines that run in diesel is being phased out is the fact that it is harmful to the environment. Unlike gas engines, which do not emit any smoke, diesel does, thick black smoke that are very harmful to the environment.

General Information On Diesel Engines

Diesel engines offer the lowest specific fuel usage
of any other large internal combustion engine. The
fact remains, two-stroke diesels with high pressure
forced induction, particularly turbo charging, make
up a large percentage of the largest diesel engines.

Throughout North America, diesel engines are generally
used in larger trucks, where the low stress, high
efficiency cycle will lead to a much longer engine
life and lower costs to operate. These advantages
also help to make the diesel engine ideal for use in
the heavy haul industry.

Cars however, continue to use gasoline, primarily
due to the consumer desire for a wider range of
RPM. In Europe, the use of diesel engines with cars
is far more common.

Even though diesel engines are more efficient when
throttled down, they aren't suitable for most types
of aircraft. The higher compression ratios of the
diesel cycle demand a much stronger block, head,
and almost all moving parts in general. These
stronger parts add a lot of weight, or a lot of
expense, especially if lighter alloys are being used.

The Otto cycle engines are much cheaper to build for
these reasons, although they have long been overtaken
by the turbine engines. For the same displacement
of the engine, Otto cycles will produce more actual
power than a Diesel cycle can, because the fuel
will burn at a much faster rate, allowing more power
strokes per minute than a standard diesel can offer.

What this means, is that less fuel has to be carried.
Additionally, commercial aircraft is normally run
at preset limits, so that Otto cycle engines used
in aircraft don't suffer anywhere near the efficiency
penalties that land vehicles do. Heavy equipment,
such as those used in mining and construction,
almost always uses diesel engines.

Diesel engines are also used with submarines. In
these types of submarines, the diesel engine is run
when the submarine is on the surface, which charges
the batteries that power the submarine once it is
submerged.

All across the world, diesel engines serve many
different purposes. They are used with almost all
types of heavy machinery, and other vehicles. Gas
isn't the way to go with heavy machinery, as the
engines simply can't withstand the beating.

Diesel has been popular for many years with machinery
and submarines, simply because the engines can
last for years and years. Although they won't offer
as much speed as gasoline, the torque and power is
still there.