Which towing vehicle is best for a full-size, Ultra-Lite trailer?

Andy,

Using custom weight distributing, we’re pulling a 1,750-pound pop-up with a Toyota Camry. It performs great, but we’re thinking of upgrading to a full-size trailer and new tow vehicle.

We’re a family of four, and our dream floorplan is a 28-foot Ultra-lite layout with a small slide-out. Loaded, it would weigh 5,000 pounds. I’ve narrowed down our potential tow vehicle to either the Toyota Sienna (4-wheel drive) or the Toyota Sequoia. We live and camp in Colorado, so the ability to climb grades at high altitude while towing is a requirement.

For the Sienna, we would wait until the ‘07 model year for the 3.5L (268hp @ 6,200rpm, 2,48lb-ft @ 4,700rpm 5-speed auto transmission, 3.29 final drive ratio).

The center of gravity would be lower on the Sienna, though the tow rating is much higher on the Sequoia. It also has better gearing for towing (4.10:1), and the torque is lower in the rpm range (314lb-ft @ 3400rpm). There’s also no commercially available hitch for the Sienna, which will handle more than 500 pounds of tongue weight. The wheelbase is about the same (118 inches on Sequoia, 120 inches on Sienna).

As you’ve probably guessed, we’re leaning towards the Sienna (it’s definitely the better vehicle for us, if towing isn’t considered). Using a Sienna, would it be safe to tow the trailer I’ve mentioned?

Thank you very much for your input.

Mike

Mike,

Certainly you tow regularly in what is likely the most challenging environment in the U.S. or Canada. The Eisenhower tunnel heading west out of Denver is 11,100 feet at the top, or to put it another way, it’s equivalent to the 5,700-foot Coquihalla pass in BC – times two.

Though most roads at these elevations are graded pretty well (usually seven percent maximum), the challenge is thin, dry air. This results in a loss of power, though not nearly as much as it once did, thanks to the capacity of fuel injection to compensate for it.

As well, thin air on a dry day has very little water content to absorb heat. A vehicle that can easily stay cool on a long, low-gear hill in 100-degree, 70-percent humidity in South Carolina may not be able to stay cool in high altitude conditions with dry air. This is not a catastrophic problem if you travel to Colorado once in a while, as you can turn the heater on, or pull over at one of the many pull-outs, and let the engine cool down. However, it would get on your nerves if you were doing it every weekend.

I’ve crossed I70 a few times, and twice with Chrysler Intrepids towing Airstreams that are more aerodynamic than the trailer you’re considering (but also 3,000 pounds heavier).

During our last trip, we did need the heater while on the highest passes, but the conditions in August 2002 were extremely dry and hot. Power was not an issue. While on our other trips, there weren’t any heat problems.

The Sienna has more cooling capacity than the Intrepid, and none of our customers with Siennas have had even a trace of overheating, so I wouldn’t be concerned about the capacity of the cooling system. The worst-case scenario would be to install a larger radiator, but I doubt you’ll need it.
...

(Read the full article in the magazine) (Page Top)