What size trailer should I start considering diesel?

[nomad_archer]

I'm still in the market for a new TV. I thought I was all set on a F350 SRW gasser when my wife mentioned that she would like to upgrade in the next 5 years to a new TT with a rear bunk house. Looking at some of those floor plans it appear that total trailer lengths range from just over 30' to about 37' and GVWR that come in around 10k. This made me stop and wonder at what point length or weight should I start thinking harder about diesel? Maybe I am just over thinking this but I thought I would ask the folks here that have a bit more experience at this than I do.

[V3600]

Both gas and diesel will get the job done, diesel just does it better. My first experience with diesel was pulling my 24' boat. I had a gas truck with so-so performance towing in the hills. Pulled it with a friends diesel and it was night and day difference. I've never gone back to gas. Point is it doesn't matter the weight or length your towing but rather how well you want to tow. Torque is your friend and that is diesel.

[Podivin]

In MY mind (and I'm not a guy that tows stuff) it might be more important to think about at what point do you start considering a dually for the tow vehicle.
I don't pretend to know the answer, just thought I'd bring up the question.

[450Donn]

Length is rarely an issue. Heck a 1500 can easily tow an empty 40 foot flst bed trailer. The issue is always weight. Personally I would go with a diesel for sure any trailer that weighed ready to go over 10,000 pounds. But diesels are so much more fuel efficient, love to work and such a joy to own I wiuld pick a diesel anythime I wanted a serious tow vehicle.

[Chargerman]

I would think about how much towing you think you will be doing when you have that trailer. If it is going to be frequent I would be diesel shopping but if you are only going to tow it 5-6 times a year in your region then the extra 8k$ investment for a diesel would not be the best investment. I have owned a few diesel trucks and the power is awesome but that was when the diesel option was only an extra 4K and the fuel mileage was much better than gas. Then the emissions regs came into affect and mileage has dropped along with the need for DEF. The dealer has continued to try to get me back into a diesel when I update my truck. Telling me how many more miles the engine is good for, Etc. But since I update at 100k miles I will never benefit from it. I used to tow every other weekend and a diesel was well worth the investment and I loved the power. Now I only tow a few times a year so I stay with gas. Did I love the diesel, absolutely. Is it worth the significant extra cost to me based on my use, no

Sorry if my input got long winded.

Best of luck with whatever decision you make.

[Ramtop]

The diesel guys will tell you that you absolutely need a diesel to tow. Used to be that there was a big difference in power towing between gas and diesel. Nowadays, the new gas engines available are much more powerful and efficient, closing the gap between the two versions. Diesel will shine at higher altitudes with the turbos and exhaust brakes helping to stop. But, diesels cost more up front and more to maintain. Gas engines today are a very good option towing some pretty big campers especially if the truck is set up correctly with the right transmission and correct rear end gearing. If you are doing a lot of towing then diesel makes more sense. If it is occasional a good gas engine will get the job done cheaper.

[Wileykid]

At the weights that you are looking at, I would factor more on the type of terrain that you will be towing in. Going to put a lot of miles on, sure. Going to be in mountainous areas a lot, sure. But if most of your towing at those weights area 3-4 trips a year, or mainly flat land areas, diesel is more than you really need. Gas engines in the newer trucks are really good, and cheaper maintenance. Much over 10K pounds, then diesel does look better. Dually for the weights you are talking about is overkill. I personally would only consider a dually when the weights are around 15K pounds or more.

[Chargerman]

My current truck is a GMC 2500 crew cab 4x4 with a 6.0 engine. Tow a gooseneck 4 horse trailer. Trailer weight loaded is about 11k. My truck tows it fine loaded. Yes, slower on long hills with the engine reving around 3200 but that is what it was designed for. Previous truck was a Ram set up the same with a 5.7 and towed exactly the same as my GMC. The only thing about the Ram I didn’t like when towing was that the first two gears were too tall, even with the 411 rears. I must say the Longhorn Ram was much better in creature comforts

[tuffr2]

To add confusion both Ford and Ram are working on a 7.xx liter gas engine. This will bring gas engines closer to the diesel capibility but still way behind. Even if the new gas engine produces 500 ft.lbs of torque the diesel engine will produce 950 to 1,000 ft. lbs of torque.

Towing with a diesel truck is a non-event. I could go up a mountain and not even notice. The modern diesel engine has gobs of power. The 8k initial cost is mostly recovered at the back end. My diesel
dulley towing my 16,000 lb. 5th wheel - the truck rode better, and made for a very pleasant towing experience.

Here is the but - after 6 or 8 years what will go wrong? The injectors are high pressure at 35,000psi, any water in the system is bad, any bad fuel is bad. How long will the EGR last, how about old DEF, what if the truck sits too long? Who do you trust to do an oil change? Owning a diesel truck does not come without some added worry as they are more complex.

The question to me is, how long are the modern diesel engines reliable?

Gas engines are reliable for 20 or more years IMHO.

[tco0608]

A few thoughts from my experiences, yours may vary.

Length to me is part of the factors in picking a TV, as does the type of trailer.

A 31 foot travel trailer (vs a flatbed, car hauler) has a lot of sail area. A 7500 lb 31 foot trailer will have a lot of momentum in a cross wind, with half tons trucks getting lighter and lighter, they can not win the battle with the TT and get pushed around.

Move up to a heavier over all truck, with stiffer suspension and it handles the 31 foot sail much better.

Will a gas 3/ ton do the job, yes it will and it will do it fine as other have stated, it will drink gas, it will climb hills slower, it going to rev to do it.

If I were to buy another gasser, it would be a GM with the 6.0 Vortec. You can but the tac on 4500 and just let it eat climbing up a mountain. It will do it all day long and on 87 octane gas.

If tow a lot, and that includes mountains like here in VA, or go longer distances, then the diesel starts to make more sense.

Instead of 9-10 mpg I get 15 towing. I go further on a tank of fuel. 910 ft of torque means it's going to keep its speed on hills and mountains.

My current camper is 9000lb, I would really rather have a diesel over 7500lb or so.

[nomad_archer]

Thanks lots of good info. I would hope to use the camper lets say 10ish times a year and I would be staying regional within 8 hours of home. If we were to get adventurous and make some longer trips I would still be staying on the eastern half the US. We have big hills/mountains here but they are nothing compared to western mountains and the rockies. My other towing will be occasional and probably 5k lbs or less depending on which boat we get next.

It feels like the gas engine still maybe the correct choice for me because the truck will be a TV and will most likely spend a good bit of time sitting between trips. As for gas mileage I currently get 10-14 with my current camper and little truck and I wouldn't expect to get much better with any TV. I accept that the gas mileage will stink because I am towing a big wind sail behind me.

[SmokeyWren]

Originally Posted by nomad_archer

Looking at some of those floor plans it appear that total trailer lengths range from just over 30' to about 37' and GVWR that come in around 10k. This made me stop and wonder at what point length or weight should I start thinking harder about diesel?

I towed a 9k 5er for around 100,000 miles over 10 years with a Ford 7.3L PowerStroke diesel. I put a total of 200,000 miles on that drivetrain, so only about half the miles were towing. The only major repair to that truck during that 200k miles was a transmission overhaul at 112,000 miles. (The 4R100 tranny had an average life of around 100k miles before an overhaul was required.) I hot-rodded the engine with a mild towing tune that resulted in 300 HP and 600 lb/ft torque at the rear wheels. East and west, north and south, every mountain range in the lower 48. I would not want to tow an RV trailer that grosses much more than that 9,000 pounds with a gasoline engine.

The current Ford 6.7L PowerStroke diesel has a lot more than 300 HP and 600 lb/ft torque (Ford specs say 450 HP and 935 lb/ft torque), so no need for hot-rodding the engine to drag a 10k 5er over the mountain.

After 10 years and 100,000 towing miles, I ceased extensive travel and downgraded to a small 20' long TT without a slide and with GVWR of 5,600 pounds and tow it with an F-150 Ford 3.5L EcoBoost engine. That small TT actually grosses less than 5,000 pounds when wet and loaded on the road. Wonderful towing engine for a TT grossing up to around 8,000 pounds, but they don't make them for anything bigger than a half-ton pickup. And I would not tow a 9k or 10k TT with a half-ton pickup.

So assuming a 10k TT, or even a 10k 5er, I'd want at least a three-quarter-ton pickup with a diesel drivetrain. If I were buying a new tow vehicle to tow a 10k TT, I'd probably buy a one-ton with single rear wheels (SRW) to have the extra payload capacity available, "just in case". With that tow vehicle, length of a TT is not a factor. The heavy diesel drivetrain compensates for the increased aerodynamic drag caused by cross winds and passing 18-wheelers. The receiver hitch tongue weight limit is probably the limiter as to how heavy a trailer you can tow without exceeding any of the weight limits of the tow vehicle. And the tongue weight increases as the trailer length increases. So be sure the receiver hitch on a new tow vehicle can handle the max of 1,500 pounds tongue weight of a 10k TT.

[ScoobyDoo]

Back in the early '70s I hauled material with spark plug motors. (Back then if a Ford said "Super Duty" part of VIN would be F850) The first time I fueled with diesel after a day of grossing over 100,000 lbs I made up my mind I would never buy a truck that I expected to gross over 30,000 that was not diesel. But now, I would really need to look at what percentage of the time I would be towing, and how many miles I plan to drive. Given I live long enough, will I drive enough to wear out the gas engine before the rest of the truck rusts away? Will I drive enough, in a short enough time, to save enough on fuel to pay the cost difference? That minute you save going up a hill might cost a bunch...

[Ramtop]

One thing to calculate in your consideration is cost if that is a factor in your decision. Gas trucks cost less, maintenance cost are less due to smaller oil reservoirs. On the flip side, diesels get better mileage but have the added expense of also buying DEF. Between the extra cost of a Diesel engine, DEF, more expensive oil change, it takes a lot of mileage to make up the fuel savings between gas and diesel.