A Heated Debate: Gas versus Diesel

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.

Read More about Marks in depth discussion Gas Vs Diesel:
http://www.rvuniversity.com/article.php/20070516070737817

RV Fire Safety...What's Your Plan?

Did you know that there are close to 20,000 reported RV fires each year? Do you know what to do in the event of a fire in or around your RV? If you said no don’t feel bad, because there are a lot of other people who don’t know either. Over 25% of RV fires are caused by shorts in the 12-volt electrical system. Not only do you need a fire extinguisher, but you need to inspect it before each trip to make sure it is charged. Look to see if the arrow is pointing in the green area in the sight gauge. If it reads empty or needs charging replace it or have it recharged immediately. If it’s a dry powder type fire extinguisher the arrow pointing in the green doesn’t always guarantee that it will work.

Read Mark's in depth article about Fire safety: http://www.rvuniversity.com/article.php/20070514105149937

Copyright Mark J. Polk, owner RV Education 101

Pesky RV Critters

When RVs are stored for the winter it’s not uncommon for mice and squirrels to make their winter home in the RV. These animals are notorious for chewing through vehicle wiring, plastic and rubber lines, causing extensive damage to the RV.
Possibly, the most important step is to try and prevent mice and other rodents from being able to access your RV. This can be difficult because they can enter the RV through some very small areas.

Start by inspecting the underside of your RV for any gaps or holes. Fill these gaps using silicone or expanding foam. A word of caution, if you never used expanding foam before you should experiment with it on something other than your RV first. When it dries it can expand a great deal more than you expect. Next, open drawers and cabinet doors inside your RV. Look in all of the corners and crevices, especially where plumbing and wiring enter the RV. If you can see any daylight mice can get in. Fill these areas with silicone or foam.

I don't recommend any type of poison. It can take several days for the poison to work and the mice will usually die somewhere that you can't find them. If this happens you may never get rid of the smell. If you do use poison make sure pets can’t get to the areas where you put it.

Read Mark's In depth article on rodent control:
http://www.rvuniversity.com/article.php/20070510162451772

Copyright 2007 by Mark Polk, owner of RV Education 101

Defensive Driving = Smart Traveling

Forty thousand people in the United States die each year on the road!

Avoid driving or pulling your RV during bad weather and high winds. Because of the size and mass of RV’s it can be extremely dangerous to travel during periods of high winds. It’s better to get to your destination one day later, than to risk traveling in bad weather.

Eventually you will have to pass another vehicle in your RV. It's not difficult to pass but with a large RV it requires more space and time than the average automobile. Make sure you have plenty of room and use your turn signals to change lanes. Accelerate until you are past the other vehicle and you can see both of their headlights in your side mirror. Signal again to return to the other lane and pull back in. Maintain your speed ahead of the vehicle you just passed.

Read Mark's in depth RV safe driving article:
http://www.rvuniversity.com/article.php/20070510143232128

Copyright 2007 by Mark Polk, owner of RV Education 101

Be Prepared for Bad Weather RVing

Something many RVers do not take into consideration with the freedom to roam is the weather conditions where you are traveling to, or spending the night. RV's are great, but they are not safe in severe weather, like lightning and thunderstorms with high winds, tornadoes and hurricanes.

Every RVer should own a weather radio receiver. Prices for receivers can range anywhere from $25 to $200 depending on the quality of the receiver and the features it has to offer. We actually have two weather radio receivers. Both are from The Weather Channel® Stormtracker™ series by Vector. We leave the Compact Storm Tracker in the RV at all times. It’s a TV with a five inch screen, an AM-FM radio, emergency weather radio, cell phone charger and flashlight all in one. When we arrive at our destination we set it in the ‘Weather’ position and tune in to the NOAA station with the strongest signal in that area. Then, by leaving the Storm Tracker in the alert/lock mode 24/7, when an all-hazard emergency or weather alert is broadcast by NOAA, the Storm Tracker sounds an audible alert to notify us that a message is pending.

We also have a handheld Stormtracker model that we can use when we are away from the campground. It’s perfect for hiking, riding four-wheelers, boating and many other uses. Both models work off of 12 volt DC, 120 volt AC and dry cell batteries. There is also a back-up power system, furnished by built in rechargeable batteries. The rechargeable, battery is a secondary power source for emergency use when the battery, 12 volt DC power or 120 volts AC are not available. If the power goes out for a long period of time, and all of battery sources have been depleted, both radios have a hand crank that can be used to recharge the batteries and continue to operate the weather radio, flashlight and cell phone charging port. When you get back home, you can use the weather radio receiver in your house.

For more information on the NOAA Weather Radio visit their website at www.nws.noaa.gov/

Read Mark's in depth article on bad weather RVing:
http://www.rvuniversity.com/article.php/20070510123918354

Copyright 2007 by Mark J. Polk owner rveducation101.com

Are You Braking the Law?

A topic that is sometimes overlooked, and seldom talked about is supplemental braking systems. It’s not about what supplemental braking system you have, it’s the fact that you have one!

One requirement for towing a trailer is that the trailer must have a braking system that works in conjunction with the tow vehicle brakes. Why should this requirement be any different for a motorhome towing a vehicle? In reality its not, but most people just assume you don’t need a supplemental braking system for the vehicle you’re towing. Some reasons for this assumption are:

1) Because of the size of the motorhome there is no need for a supplemental brake system on the tow vehicle.
2) People assume the vehicle they are towing is much lighter than it really is.
3) Braking laws are not always enforced by individual U.S. states and Canadian provinces.
4) Nobody took the time to educate the RV consumer on the requirement for a supplemental braking system.

Regardless of the type or model you choose, being able to stop completely, in less time and a shorter distance, will give you an added sense of safety whenever you’re towing a vehicle. And it’s the law in most cases. Most importantly, a supplemental braking system SAFELY reduces the stopping distance and helps to protect you, your loved ones and the safety of others.

Read Mark's in-depth article on supplemental braking systems:
http://www.rvuniversity.com/article.php/20070510084958709

Copyright 2007 by Mark J. Polk, owner of RV Education 101

May 2007 RV Questions & Answers by Mark Polk

RV Education 101 is Sponsored by National Interstate Insurance Company

*NOTE: At Mark's discretion, material might be edited to suit a wide audience. Due to the large volume of material and correspondence we receive, individual replies might not be possible, nor can we acknowledge receipt of submitted material. Selected questions will be answered in future issues of our RV Education 101 newsletter and on our site. Thank-you for your understanding.

Q: We have a Pop Up and my husband and I can never seem to back it in to the camp sight where we want it to go. Do you have any advice or ideas?

Mark says: I have a method that has always worked well for me with two people working together. First decide who will drive and who will give directions. Let’s say your husband is driving. For this to work you are his eyes and he needs to do exactly what you tell him. When you are ready to back it in, you stand in front of the vehicle where you can see the trailer and communicate with your husband. He puts his hand on the top of the steering wheel and slowly turns the wheel in the direction you tell him. If you want the back of the trailer to go to your right you tell him to turn the steering wheel to the right. If you want it to go to the left tell him to slowly turn the wheel to the left. Don’t get upset if you need to pull forward and start over. With a little practice you’ll be backing like the pros. There is an excellent video available that not only demonstrates methods for backing a Pop Up, but it covers everything you need to know about using Pop Ups too. http://rveducation101.com/detailedinformation.asp?ID=1454

Q: After we decided to buy a travel trailer the dealer told us we would need to spend another $1,000 dollars on hitch work. Isn’t this a little unreasonable?

Mark says: The dealer should have explained the importance of proper hitch work during the sale. It is for your own safety and the safety of your loved one’s. If your particular purchase requires a weight-distributing hitch, dual cam sway control, electric brake control and wiring then 1,000 dollars is not unreasonable. Any reputable RV dealer will not sell the trailer without the proper hitch work.

Q: I have heard people talk about the 75% rule of thumb for towing. How does this work?

Mark says: There is some confusion on this subject. A lot of people say that you take the manufacturers tow rating for a vehicle and multiply it by 75% and this is the maximum weight you should tow. For example a tow rating of 8,000 pounds X 75% = 6,000 pounds. The 75 % rule is designed to build in a margin of safety. The way that I understand it and apply it is that you take the Gross Combined Weight Rating (GCWR) of the tow vehicle X 75%, and the Gross Vehicle Weight Rating (GVWR) of the tow vehicle X 75%. Once you determine this you subtract the two and this is the maximum weight you should tow. Using the same example above that vehicles GCWR is 14,000 pounds X 75% = 10,500 pounds. The GVWR is 8,800 X 75% = 6,600 pounds. 10,500 minus 6,600 = 3,900 pounds. I apply this rule if you plan to tow in high elevations. A gasoline engine looses 3 to 4 percent of its power for every 1,000 feet above sea level. The 75% rule compensates for that lose in power.

Q:My 2006 Toyota Tundra Quad Cab truck has a GCVWR of 11,800 (12,200 from another source), let's be conservative and say 11,800. The truck does have factory installed towing package. Tow rating on truck with tow package is 7100lbs according to owners mannual. Trailer has dry weight of 5190 and gross weight rating of 6500lbs. My estimates on cargo and add on's, I have estimated at around 850 to 900lbs. If we did any dry camping it would be very rare. So I'm not allowing for a lot of water weight.

So, loaded trailer weight should be about 6040lbs. Looking at it from this point I have almost 1100lbs of slack. But from at GCWR I'm pushing the envelope on weight. I do have a oil cooler with tow package. I have a prodigy brake controller, and I'm going with your recommendation and purchase an "Equalizer" hitch. They are kinda of high $$$, but I feel it will be money well spent. My truck also has a tow mode on the transmission. It takes it out of overdrive and runs the truck in 3rd gear. (There goes gas mileage!!)

The Jayco trailer I am looking at and the weight of the truck, put me at 98% of the GCVWR. I know the lower percentage the better, but what I can't get a straight answer on is being at 98% will the truck still pull O.K. I don't want to put the truck in a bind, and I don't want to spend 20 minutes trying to get up a hill either. I have weighed my truck on a scale as recommended. It was loaded and full of gas. I probably went a little overboard putting fire wood in the bed to get some extra weight. Just trying to figure on high side. I have also taken dry weight of trailer and have added for propane, hitch weight, some water, and personnel food and gear. (Food & Gear I used about 350lbs.) Just some added info. Based on the length of the wheel base of my truck. I'm just about at the maxium on trailer length too. I am going to purchase weight distribution and sway control hitch. I just can't get a clear answer on towing ability at these weights from anyone. You're not trying to sell me a travel trailer, so any information you can provide me will be helpful.

I also have purchased your Video Series: http://rveducation101.com/detailedinformation.asp?ID=2169on RV's and have gained a lot of information. This is our first RV and we have a lot to learn. We need all the help we can get.


Mark says:I had a chance to review the information you sent. I have always said if the tow vehicle tow rating is higher than the trailers GVWR you are in pretty good shape (as long as you don't overload the trailer). And the key to the GCWR is to keep it below the GVW of the combined truck and trailer which you are, even though it is at 98%, it is below. If you plan to pull the trailer in the mountains a gas engine will loose 3 to 4% of its power at higher elevations and you may want to re-calulate your figures.

Copyright 2007 by Mark J. Polk owner of RV Education 101

RV Expert Mark Polk, seen on TV, is the producer & host of America's most highly regarded series of DVD's, videos, books, and e-books. http://www.rveducation101.com/