Andy
Offers Tips on Improving the Chevy TrailBlazer’s
Towing Performance.
I bought
a Chevy TrailBlazer a couple of years ago as a tow
vehicle for our Jayco Jay Feather 21J. The TrailBlazer
has power to spare and it has been reliable, but there
are a few issues I’m having with it.
I’ve noticed the rear springs and the shocks
seem to be soft. Passing vehicles make the truck sway,
even without a trailer. Rebound takes three to four
cycles over some road irregularities. The tires seem
soft as well, and low pressure, balloon tires don't
help control sway either. Finally, it loves gas at
16 mpg (city).
I spoke with a salesman at your dealership about using
a Freestar as a tow vehicle, and he indicated that
with modifications it would tow our trailer easily.
What modifications would be needed? Our hitch uses
square bars rated for 1,000 pounds.
Any advice is greatly appreciated.
Mike Clark (Cambridge, ON)
Hi Mike,
If you were towing a 30-foot, light trailer, the Freestar
would be substantially more stable, but a 21-foot
shouldn’t be a problem for the TrailBlazer to
handle with a few relatively simple changes. This
would far less expensive than changing tow vehicles.
The TrailBlazer’s 4.2-litre inline six is a
wonderful engine. It’s mated to the same transmission
that is used in full-sized pickups that have much
larger engines. It’s a great performer and has
a very durable drivetrain. If you’re checking
your fuel economy with the built in computer, remember
that it’s US miles-per-gallon that you’re
reading. 16 mpg (city) is pretty good for any SUV,
and I doubt the Freestar would do much better. Changing
the tires on the TrailBlazer should improve fuel economy
slightly. In two or three years, we should have access
to tow vehicles that will deliver dramatically better
mileage.
Obviously the TrailBlazer’s suspension is tuned
for a smooth ride. The good news is that it’s
not difficult to give it far more control.
The soft springs shouldn’t be a problem for
your trailer. In fact, they may work out well. A suspension
system that combines springs slightly on the softer
side with stiff shocks and tight tires will give a
great deal of control without a harsh ride. If the
springs are too stiff, adding more control on top
of the springs makes for a stiff riding combination.
If your trailer was heavier, then stiffer rear springs
would be necessary.
A good set of heavy-duty gas-charged shocks will tighten
the suspension up considerably. Monroe Sensa-Tracs
should work very nicely.
The stock 245/70R x 16-inch tires have substantial
sidewall sway. There are two ways you can improve
your tires on this vehicle. One is to change your
tires to 225/75R x 16-inch LTT (Light Truck Tire).
This tire is a load range “D”, or eight-ply
rating. It’s a stiff tire for the weight you’ll
be carrying on it, and it will provide you precise
handling. The downside is that it generally has a
pretty hard rubber compound, meaning it’ll wear
like iron but sacrifices some traction, especially
on wet roads. The tire’s diameter is the same
as your current tire, but performance and mileage
will be better due to the reduced rolling resistance.
The tire is rated to carry 65 PSI, but you would never
run them that hard, 40 to 45 PSI is plenty.
The other size that can work well is a 235/60HR x
16-inch. This would be a high performance tire with
a 44 or 51 PSI capacity. The rubber compound will
be softer, so traction will be very good at the expense
of tread life.
You need your speedometer recalibrated for this tire
as it will run nine percent faster than with the originals.
These will give you substantially more power when
towing, and fuel mileage will be a little better.
They will ride better than the light truck tires,
and have more traction than your current ones.
With these two changes you’ll notice a world
of difference in the handling, both towing and driving
solo.
My only other concern is the hitch you’re using.
It’s very stiff for a trailer this light on
such a short tow vehicle. In fact, your torsion bars
are stronger than the hitch receiver, so it’s
likely flexing as much as the torsion bars are. The
resulting effect is the trailer steers the back of
the tow vehicle, instead of working in concert with
the rear suspension. I would suggest a round bar hitch,
where the bars are completely enclosed in the ball
mount with 750-pound bars. The round bar design has
more travel when you go through deep dips, and they
should ride considerably better. As well, I would
consider adding a good quality friction sway control.
For those of you considering a TrailBlazer or Envoy
as a tow vehicle, you might want to look at the extended
wheel base version. It still has a soft suspension,
but the long wheelbase adds a lot of stability. A
full rear-air suspension system is optional on new
models, but it’s not good for towing with an
equalizing hitch.
If you want an outrageous performer, you could have
fun with the TrailBlazer SS, which has a 6.0-litre
engine with 400 hp, 20-inch wheels with 55 series
tires, and a much more controlled suspension. Too
bad you can’t get the suspension package with
the six-cylinder engine. (Page Top) |
