Tow Vehicle - GAS or Deisel

[MikeWard]

Fellow RVers,
I don't want to start any major problems between the owners of these two TVs but I just like some simple info. I have been reading this group inputs to learn whatever I could to allow me to make the best decision I can on a new fiver and tv when I start what I hope will be longer and further rving trips. I know that with new fuels for deisels coming out and it seems the cost of deisels are getting higher I just need some info to justify whatever decision I make. What I am interested to know is do just as many RVers use gassers as there seem to diesels. I'm sure there must be many of you who drives a gasser. What I would like to know is:
How well does a gaser perform in the mountains (up and down) towing a fiver? Anyone who would like to share their methods of doing this
please feel free.
Is it really necessary to have 4 wheel drive?
Is it really necessary to have a dually? I know this can depend upon trailer hitch weight, but does it really help with stability?
Are there mods that can be done to a gasser to to increase performance when towing?
Are there any recommendations as to what truck is best suited (engine, gear ratio, and etc)?

I guess what I am asking is can a gasser get the job done?
At present I do not own either a gasser or diesel (but have rved for many years). I am hoping to do a lot more in the near future and am gathering info so I can make the best decision possible.

Thank you for your help.

Mike

[MikeWard]

Fellow RVers,
I don't want to start any major problems between the owners of these two TVs but I just like some simple info. I have been reading this group inputs to learn whatever I could to allow me to make the best decision I can on a new fiver and tv when I start what I hope will be longer and further rving trips. I know that with new fuels for deisels coming out and it seems the cost of deisels are getting higher I just need some info to justify whatever decision I make. What I am interested to know is do just as many RVers use gassers as there seem to diesels. I'm sure there must be many of you who drives a gasser. What I would like to know is:
How well does a gaser perform in the mountains (up and down) towing a fiver? Anyone who would like to share their methods of doing this
please feel free.
Is it really necessary to have 4 wheel drive?
Is it really necessary to have a dually? I know this can depend upon trailer hitch weight, but does it really help with stability?
Are there mods that can be done to a gasser to to increase performance when towing?
Are there any recommendations as to what truck is best suited (engine, gear ratio, and etc)?

I guess what I am asking is can a gasser get the job done?
At present I do not own either a gasser or diesel (but have rved for many years). I am hoping to do a lot more in the near future and am gathering info so I can make the best decision possible.

Thank you for your help.

Mike

[Kiwi]

I towed a Fifth for a number of years, first with a gas truck then with a diesel.

At the same time, our close friends also moved from pop-up to a Fifth.

I now drive a diesel pusher class A.

Here is what we learned:
If you drive mostly in flat country, and not very often a properly sized gas truck can be good value. However you must have patience when you drive, and be willing to take the fuel usage hit when you do hit even easy hills.

If you can afford a diesel, you will enjoy being able to pass gassers as they struggle up even easy hills.

At altitude, a gasser can lose 3% of its power per 1000 feet of altitude. So if you want to drive along the trail ridge road in Rocky Mountain National Park (12,000 ++ ft) be prepared to work to get up there with a gasser. This may mean crawling up at 10 to 25 miles per hour in first or second gear. My diesel went up at highway speed towing a 4500 pound toad.

There is no doubt that you will enjoy a diesel. There is good probability tht after buying a gasser and experiencing towing you will then want a diesel. If you do not have the financial strength to buy the wrong truck then take the hit on trading it for a diesel, you may consider stretching for a diesel now.

As to dually vs single wheel axle, that is a function of load. However, be aware that duallys do not have as good a traction as single wheels. They tend to be called a "sled" by owners. So don't buy one unless you really have a heavy pin weight rig and need it.

Also, you may consider not depending on the salesman or the factory sticker for pin weight. If you have not weighed it, you don't know the pin weight.

My friend had a 1/2 ton gas rig. He was told that the big Fiver he was buying could easily be towed with his rig. The day he picked it up and they lowered the rig on the hitch, his headlights started searching the sky. He then had to go get air bags installed. The truck overheated and he wound up trading for a 2500.

That pulled it fine but drinks gas.

A lot of the decision you are struggling with is personal and depends on your finances, need for a truck in other areas of life, rig size, and travel plans.

Walt

[RustyJC]

Mike,

First of all, welcome to iRV2.com. Glad to have you on board.

Insofar as your question is concerned, I've pulled 5th wheels both ways - a 1996 Dodge Ram 3500 dually with V-10 and 47RE automatic, and my current 2002 Dodge Ram 3500 dually with Cummins HO and 6-speed manual.

The V-10, to its credit, did the job reliably, but it was thirsty (6.5 MPG with the last 5th wheel we towed with it) and ran the 6% grades at 55 MPH in 2nd gear at 3500 RPM. The Cummins, on the other hand, pulls our current 5th wheel (significantly heavier) while getting 9.5 to 10.5 MPG and will handle the 6% grades at 70 MPH in 6th gear.

Not to get too technical, but a fundamental difference between the gas and diesel engine is the shape of the torque curve. The V-10 produced 450 lb-ft @ 2800 RPM while the Cummins (in stock trim) produced 505 lb-ft @ 1600 RPM. This means that when cruising down the Interstate, the V-10 was running "on the front side of the torque curve" or below peak torque RPM while the diesel is running "on the back side of the torque curve" or above its peak torque RPM.

The significance of this is that when the trucks encountered that 6% grade, the V-10's torque dropped as the engine speed dropped, forcing a downshift to 2nd to get the engine RPM above the 2800 RPM torque peak in order to make sufficient BHP to hold speed. The diesel, on the other hand, increases torque as RPM drops, so it could pull the same grade without a downshift and while holding road speed. That is why the diesel (rated at 245 BHP stock) could pass the V-10 (rated at 300 BHP stock) in real world conditions going up the same grade.

Most upgrades you can do to the gas engine will tend to increase BHP in the higher RPM ranges and move the peak torque RPM even higher - not much help for towing unless you want to rev the engine hard to get the additional performance, and that gets old pretty quickly in terms of noise and fuel consumption.

If you're going to tow a 5th wheel of any significant size and weight and want to stay within the truck manufacturer's GVWR and rear axle GAWR ratings, the dually is the right tool for the job.

Rusty

[Ed-Deb]

Both of the replies here are well written and explain (briefly) the pros and cons of diesel vs gas.

If you are going to be towing anything with some weight I would highly recommend getting a diesel rather then a gas rig and later having to upgrade to a diesel.

Most people seem to start out "small" and move up in both RV size and TV (if applicable).

I started with a pop up tent trailer after back packing and sleeping on the ground for years. (My back dictated the move away from this type of camping).

I then bought a 2500 Dodge diesel and a 26' single slide fifth wheel. Then a 32' double slide fifth wheel. While towing the 32' I regretted not getting a dually due to the weight. (I was right at or just over the limit of the truck depending how I loaded the FW).

It is easier financially to just buy the diesel now and skip the extra step of a gas TV. The only issue would be deciding if you want a 2500 or 3500 in single wheel or a 3500 dually.

Just my $.02

[TXiceman]

Rusty and Walt have it pretty well summed up in a nut shell. For a heavy load towed fairly often, the diesel is the way to go.

I have a friend that bought a 27' Prowler TT and a F250 with a 5.4L gass engine. I tried to talk him into a diesel before hand and his wife said...no stinky noisey diesel in her drive. He used for about 2 years and was not happy going camping...about ready to chuck it all in. I told him to at least stop at a dealer and test drive a diesel. Long story short....he now has a shiney new F250 6.0L PSD in his drive now. He has made two trips with the new truck and trailer and loves to pull now.

If you are running flat ground and not doing a lot of towing, the gasser will do, but if you plan long distant and frequent trips...get the diesel.

Some argue that you can't justify the additional $5000 for the diesel in fuel savings...that is correct. But do look at the additional value in a 5 year old truck with and w/o the diesel. You get a large chunck of the $5000 back at trade time.

Ken

[MikeWard]

I certainly appreciate your input on this. One big question I've heard about is the new desiel fuel standards for 2007. They say it will be as bad as when gas went unleaded, instead of trying to carry what you needed the gas stations just switched over and let you worry about it. Also is desiel hard to find sometimes? I would like to try some boondocking and on some of their sites this has been brought up.

Thanks again,

Mike

[lincster]

Gasser will lose power as you go up in elevation. Diesel does not due to the turbo.
4WD is up to you. Do you go off road? Wet/snowy conditions? etc.

Dually will be more stable than a SRW for sure. I won't go back to towing with a SRW truck.

Best suited depends on the trailer you a pulling.

A pop up? A SRW gas powered truck will do just fine.
A 15,000lb 5th wheel that is 40' long? A Dually with a diesel would be the way to go.

[RustyJC]

The 2 types of diesel in question are:

Low Sulfur Diesel (LSD - 500 ppm sulfur)

Ultra Low Sulfur Diesel (ULSD - 15 ppm sulfur)

The changeover from LSD to ULSD is in progress right now and must be completed by September 1, 2006 (possible extension to October 1, 2006.) At that point, ULSD must be available at the pump.

The new engines that require ULSD are not mandated until January 1, 2007. My bet is that we will probably see a very short 2007 model year to use up stock of the old-style (less expensive) engines and then a 2008 model year that begins on January 1, 2007 when the new engines are introduced. At that time, the ULSD will be available, so there shouldn't be a supply problem.

Rusty

[Jeff_in_The_Dalles]

I think you guys covered it pretty well:

When towing a diesel will get close to twice the fuel economy of a less powerful gas rig. Most, but not all fuel stations carry diesel, but better milage also translates into increased fuel range since they usually come with the same size tanks for gas or diesel.

The diesel engine adds quite a bit to price, but as someone pointed out, if you look at Kelly Blue book and 5 year old Dodges (just for example), you get pretty much the entire price of the engine back when you sell.

I don't think anyone mentioned durability... I've known people who tow for a living who have more than 500,000 on their diesel engine w/o needing an overhaul. The chance of a gas engine living that long with constant towing is slim to none. Also, recommended oil change interval for my Cummins is 7,500 if doing short trips and towing, and 15,000 otherwise...

As far as needing a dually goes, if you are using it as a daily driver and live in narrow streets, a SRW 3500 will probably work for a 5er up to about 30'. Beyond that size I wouldn't consider anything but a dually.

As far as 2wd or 4x4 goes, 2wd pickups generally get better milage, and you also won't likely have clearance issues between the bed rails and the 5th wheel frame. I've had to use 4x4 to get my trailer up some steep, washed out loose rock roads before. In the snow while not towing, my truck is just about useless in 2wd but gets around great in 4x4 (probably due to about 1900 lbs of engine over the front axle). With a dually that effect would be even worse, and if you had to drive a 2wd dually in the winter your only hope would be to keep 3,000 pounds or more in the back of the truck.

As far as ULSD goes, my understanding is that the stations in my area have already switched, and it burns fine in older engines.

I might be a bit hesitant to get an early 07 diesel truck, though. Dodges, for example, will be running higher displacement with lower compression, and adding cooled exhaust gas recirculation and a particulate filter. Other brands will be making similar changes. Whatever your brand preference, I'd either get an 06, or wait for a bit to see how the 07's do for milage, reliability, and power.

Hope this helps...

[melon]

Jeff made a good point, diesel engines weigh a lot more than gas. I don't know why. (Maybe some of the more savvy members can explain.)

Another thing to consider with a dually is wider rear fenders. I don't know about you, but I can barelly fit in the stalls at the Home Depot parking lot with a single tire, and I know I would have ripped those fenders off in the El Pollo Loco drive thru already. If you use it more for a tow vehicle than a daily driver you wont have to worry about this, but my truck wears many hats.

As far as unpgrades go, I think the 4WD makes the most sence. Just because it is fairly less than a lot of the other un-grades, but it is one of the most helpful in a pinch. I mean it can really save your butt and can mean the difference on a good or bad trip. Then again, that depends on where you are going.

As far as gas or diesel, you have to work that out and all this really good feedback should help. I know when I bought my truck, diesel fuel was $.50 to $1.25 cheaper per gallon that gas and everyone wanted a diesel. I guess I should have seen the writing on the wall, but I couldn't tow what I have without a diesel. That allows me to get a bigger trailer and makes my wife happy with the room, so we use it more, which works for me.

Good Luck, Rod

[diandtom]

I just got another diesel last week. I got a good trade in on my 03 diesel. I wanted 4wd as I got stuck four times with the old truck. I was not off the road. If just don't seems to have the traction the gas trucks I have had, maybe it the weight of the engine and less weight on the rear tires. I got 4wd this time and towing mirrors two things I was not going to do without this time.
Tom

[TXiceman]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by diandtom:
I just got another diesel last week. I got a good trade in on my 03 diesel. I wanted 4wd as I got stuck four times with the old truck. I was not off the road. If just don't seems to have the traction the gas trucks I have had, maybe it the weight of the engine and less weight on the rear tires. I got 4wd this time and towing mirrors two things I was not going to do without this time.
Tom </div></BLOCKQUOTE>

Tom, on the issue of less traction with a diesel....not true. With a diesel you will be more apt to spin the rear tires in the exact same situation as a gasser. The reason is the diesel is developing much more torque as you comme off idle than a gasser can muster. Look at the torque curves. So if you get the least bit heavy footed...you can have the appearance of less traction.

A note to a previous post, yes a dually is wider, but it will carry a higher pin weight than a SRW. So if the pin weight is over a SRW rating, you need the DRW, not the size parking space you will fit in.

The reason a diesel is heavier than a gasser, has thicker block and heads and heavier bearings, rods and pistons. A gasser will have compression ratio of 8:1 up to about 10:1. The diesel will have a compression ratio of 17:1 on up to 20:1 or higher. Also, notice that a diesel will have a lot more battery capacity than a gasser. Take a higher torque starter to roll the engine against the compression.

ken

[Ray,IN]

Each type engine has its own pluses and minuses. Fuel cost is now close to equal. A diesel engine costs between 4-5 thousand extra. You can do the math and figure the payback on fuel, but thats' part of the overall picture. Hauling capacity, and towing capacity. This GM link says the 2500 diesel can handle 3,000lbs pin weight and the 3500 can handle 3,500lbs(bottom of page). Rear axle weight limits then enter the picture.

Ken, the reason a 2wd diesel seem to spin more easily is weight on the front tires. A bare Cummins B5.9 weighs 960 lbs, then accessories are added.This causes the front to bog down in soft areas, which in turn causes the drive wheels to spin more easily than a gas powered vehicle.