Ultralight trailers like the R-Pod are touted as being able
to be towed by smaller vehicles such as vans and small SUVs. That is their big selling
point, a big tow vehicle is not required. Enter - Wind Resistance.
Wind resistance is very important for travel trailers. The
more that there is, the greater is the stress on the powertrain and wheels of
the tow vehicle and the lower the gas mileage is. If the wind is from the
front, the speed of the trailer adds to the wind resistance, if from behind, it
decreases it. Additionally, wind resistance at slow speeds like 45 mph is
relatively minor, however as speeds are increased, it increases much faster
than the actual increase in speed. Going from 55 mph to 75 mph is a 35%
increase but wind resistance, and the strain on the powertrain, increases about
250%. (People with ‘L’ or ‘M’ rated tires take note) . Obviously, with all
these variables, ‘wind resistance’ is not a static number.
The wind resistance of a travel trailer is roughly
proportional to the ‘Total Frontal Area’ but protruding things like fenders,
rooftop a/c units or awning mounts, and the underside of the trailer, also have
effects that increase the effective total frontal area. To me, the published
Total Frontal Areas of tow vehicles for travel trailers are a subject of great
mystery and seem to be nearly worthless. However, this doesn’t bother the tow
vehicle product liability lawyers. Using a complicated formula that is based on
variables that are not apparently standard throughout the industry and that also
are apparently not publicized, they have established required Total Frontal
Areas for many if not all tow vehicles. These seem to exclude smaller vehicles.
Cynic that I am, I think that the lawyers have jumped in to
give their companies the greatest protection possible in their powertrain
warranties. The poor travel trailer manufacturers in response have carefully
neglected to announce their trailer’s frontal areas in order not to hurt their sales.
The R-Pod’s total frontal area is reported to be maybe around 50 sq ft. So,
just for fun, please look in your operator’s manual and let us know if your tow
vehicle passes or fails its manufacturers’s total frontal area requirements. I know
that my entirely satisfactory Jeep Cherokee (towing capacity 4500 lbs) fails,
and I am very interested to see who passes.