Truck Towing Capacity Question

This may belong in IMHO. Mods feel free to move it as appropriate.

We have a full size 2010 Toyota Tundra SR5 TRD with a 5.7 liter V-8 and a rated towing capacity of 10,000 lbs. It’s been a great truck so far and has only 40,000 miles on it. The only thing I’ve had to do to it was replace a rear CV joint while it was under warranty.

My wife and I are looking at getting a brand new 5th Wheel and the ones we are looking at weigh around 7,200 lbs, 8,000 lbs fully loaded. That’s 80% of the towing capacity of my 5-year old truck.

We don’t plan to be constantly crossing mountains, but we will need to once in a while. Most of the time we will be touring the Southern US during the coldest winter months (we live in Montana).

Should I be concerned about either the age of the truck or its towing capacity? I would rather not have buy a new truck, but I don’t want to kill the truck in the first year of having the 5th Wheel. Would a diesel truck just make more sense? I want to be able to take it safely anywhere we want to go in the US and Canada.

You may have to beef up your suspension and perhaps have a transmission intercooler installed for hauling up those mountains. Your local RV dealer can tell you more about requirements for a trailer that size, but it’s by no means one of the heavier ones.

Not to mention your 5.7L engine was built by Apple (iForce, yuk, yuk, yuk).

Anyway, I wouldn’t tow a fifth wheel with that. I sell GMC trucks for a living and I can tell you that you will most certainly want more grunt for that purpose. A diesel is preferable (google Chevy vs Dodge vs Ford uphill challenge, there’s a good video that shows 3500 HD diesel trucks towing IIRC a 12,000lb camper uphill) but you will be fine with a 2500HD truck with a gas motor for the purpose you state here.

It has a transmission intercooler already, it was part of the TRD package, and a somewhat beefed up suspension.

I will check out the video, but you may be just a wee bit biased… :slight_smile:

FWIW, the GMC (Chevy Duramax in this instance, with 765ft/lbs of torque) loses to both the other 3500 trucks due to having less overall power and torque than the Ford or Dodge motor. The Duramax is a more reliable platform IMO though.

Here’s the video in question. It at least gives you some perspective on what you’re facing. Bear in mind this is a very steep grade they are pulling. It’s interesting that all three trucks need the pedal mashed to the floor to maintain 55mph going up with a load behind it.

Having towed a large-ish trailer (though not a 5th-wheel trailer) several hundred thousand miles (including over Teton Pass, and other severe roads in your neck of the woods), my sense is that with only modest care you should be fine.

Assuming it’s not been abused, a 2010 truck with 40k miles is just barely broken in and has a long life ahead of it. As FGIE implies, you might not be able to bound up the steepest grades at 70mph. But with 381 hp(! - I looked it up) on tap, you should not be embarrassed.

One thing is you have to read the fine print of the towing capacity. The truck might have no problem hauling the trailer in terms of total towing capacity, but the pin weight of the 5th wheel trailer might exceed the bed payload capacity of a half ton truck. For a half ton, a large travel trailer might actually be the better option. Even though your hitch/tongue capacity is the limiting factor there, that tends to be a lower proportion of the overall trailer weight on a travel trailer compared to the pin weight on a 5th wheel.

More generally, though, I have seen it time and again with folks I know working all the numbers and determining their 1/2 ton truck or SUV will safely haul whatever bit of fun payload only to immediately enter the market for a diesel truck after their first outing. Just because you can do it doesn’t mean it’ll be enjoyable.

Uh what? Age of the truck? it’s only 5-6 years old. As long as you don’t exceed the GCWR (Gross Combined Weight Rating) you should be fine; assuming your trailer has brakes. The only reason diesel should enter your mind is if you want better fuel economy; there’s nothing inherent to a diesel engine which makes it better for towing.

The attractiveness of which is significantly diminished by its extra cost.

They tend to have better torque, and (in at least some cases) better durability at high load.

Anecdotally:

When you start pulling hefty loads, it’s always the transmission that gives out, and that seems to be for any make. I presume the HD trucks (2500/250 or 3500/350) have tougher transmissions.

I think you will find that on grades you wish you had the diesel. If you take one trip per year, you’ll probably live with it. But if you’re out a lot I think it will get tiresome.

That said, you’ve already bought the truck, so your best bet financially is to see how it goes and upgrade the mule later if you feel it necessary.

Nobody asked, but I think the Fords are the current best-in-class, though I find the styling overwrought. I own a Chevy truck, FWIW.

IMbriefE as a trailer sales person, almost everyone who was looking to haul a 5th wheel went with either a 3/4 ton or 1-ton pickup with a big diesel and auto tranny. That’s usually because they had ended up moving up to a larger 5th wheel, or were planning to at some point. 5th wheels can easily hit 15,000 pounds, especially a loaded toy hauler. Half-ton pickups are just really limited as to what they can haul. For instance, you can’t (to my knowledge) even buy a camper (other than a shell) for a 1/2 ton unless it’s a really old camper such as the old pop-top models or a Euro camper. That may have changed over the past ten years, but you’re still limited by weight. As somebody mentioned, bed loading is a problem for 5th wheels.

Again, I really recommend that you go to a trailer dealer and ask to talk to their most experienced sales guy.

Yes there is!

Diesel vehicles are inherently have more torque than petrol engines - something that’s considered highly beneficial in towing.

For long distance travel the fuel economy of diesels is a major factor.

I had a diesel motor home for a holiday - 6.2 metre length, that thing was getting around 11 km to the litre - the same as my little pusbucket 1800cc people carrier I normally drive.

I towed an 8200lbs trailer from Georgia to Alaska with a 2010 Chevy Tahoe rated for 5,000lbs. No special hitch, no sway bars, no additions to the suspension. I think you will be fine “every once in a while.”

no they do not. this is a myth. comparing like-for-like (turbo diesel vs. turbo gas engine, or NA diesel vs. NA gas engine,) the gas engine will produce as much or more torque and a hell of a lot more horsepower. the only reason diesels gained this reputation is because they don’t have any risk of detonation so they were able to adopt high-pressure turbocharging before gas engines could. Now that gas engines are going with direct injection and turbocharging (GTDI) they’re exceeding the torque figures of diesels of similar displacement and blowing them out of the water on horsepower.

is it going to be enough to offset both the $8,000 cost hit on the sticker and the higher cost per gallon of the fuel?

Possibly true, but none of those things have made it to large displacement gasoline truck engines in the US yet. The only alternative to Cummins, et al are V10’s and big V8’s that fall far behind the turbodiesels in terms of towing performance and mileage. Although they are way cheaper to run so there’s certainly an argument for them.

Maybe somewhere down the line we’ll get a GTDI V8 that gives the current diesel tow truck paradigm a run for its money.

yes, but that doesn’t mean diesels inherently make more torque, which was the claim (and is conventional wisdom, which is wrong.)

the closest we can come is comparing the diesel and natural gas versions of a specific engine. if you look at the Cummins ISL, which is an 8.9 liter engine, the diesel version produces a max of 350hp and 1,000 lb-ft of torque. The natural gas version puts out 320 hp and 1,000 lb-ft of torque. and yes, the NG version is spark ignition.

how 'bout that.

Thanks everyone. Ignorance fought. I will ask the trailer dealer and see what he has to say.

As I said, to me it’s primarily a safety issue, not about getting someplace as quickly as possible. An under powered truck towing a 8,000 lb trailer over a mountain just isn’t safe, and will likely end up with a breakdown in the middle of nowhere or destroying a perfectly good truck in the process.