|
 A
couple of issues back I suggested to a reader that
he take a look at the GM 1500 HD pickup truck to tow
his fifth wheel. We have a 1500 HD at the dealership
for our current demo truck, and have used them in
the past so I am very comfortable with this truck’s
capabilities. The reader who wrote in was looking
for an all-round truck that would be able to tow,
but would also be an easy truck to live with the balance
of the year for commuting to work and such. So this
is a truck that will likely tow about 20% of its mileage.
I guess I should have explained it further as I have
received some letters wondering why I would suggest
it and not the 2500 HD truck. One couple who wrote
in thought that the combination would actually be
dangerous to drive, thinking I was suggesting a half-ton
for a 32 foot fifth wheel.
When towing a fifth wheel one of the primary concerns
is overloading the rear axle capacity, as all pin
weight is added to the rear axle. The rear GAWR (gross
axle weight rating) is what the rear axle, tires,
springs and hardware are rated to carry by the manufacturer.
There is also a rating for the front suspension, but
towing a fifth wheel does not add any weight to the
front axle so it is not a concern to us here. Though
many tow ratings do not have much basis in fact, truck
axle ratings do and should not be exceeded. The GVWR
(gross vehicle weight rating) is what the truck is
rated to carry (not tow) if loaded to its maximum.
If you are looking at a truck all these figures are
on a sticker on the drivers door frame.
In 1999 GM introduced its latest designs of half
and three-quarter ton trucks, but the one ton was
not introduced until 2001 when the Duramax diesel
and the 8.1 litre gas engines became available. In
the new one ton truck they decided to call the single
wheel a 2500 HD and the dual wheel truck a 3500. Now
this is where it gets confusing – the 8600 GVWR truck
that was introduced in 1999 is a 2500 (without the
HD designation) if it is an extended cab but if the
same truck is a crew cab it is called the 1500 HD.
So the 1500 HD is not a half ton truck, it is a 3/4
ton in all but its name. Anything I say here about
the 1500 HD also applies to the 2500 without the HD
designation.
Though it is almost identical to the 2500 HD as a
day-to-day truck to drive, the 1500HD has a few advantages.
It is two-and-one-half inches lower, which may not
sound like much but it does make a substantial difference.
If you raise the roof on a vehicle two-and-one-half
inches but leave the chassis height the same, then
there will be a barely noticeable difference in performance.
But when you raise the entire chassis of a vehicle
by that amount, then you raise the centre of gravity
which is not as good for stability. For a day-to-day
truck, the lower height is easier to get in and out
of. As well, the lower height reduces drag to slightly
improve fuel economy and performance. Sometimes it
also allows the fifth wheel to be lower, further reducing
drag.
For frequent cold starts and short trips, a gas
engine is better than a diesel and it is certainly
quieter. Reducing the drag of the truck allows the
6.0 litre engine to have more power left over to tow
the fifth wheel, while delivering reasonably good
economy both towing and solo.
So other than the height, what are the differences
between a 1500 HD and a 2500 HD?
Brakes are almost identical – the rear rotors on
the 2500 HD are 1.1 inches thick as opposed to 1.4
inches thick on the 1500 HD, but otherwise they are
the same. The frame on the 2500 HD is made with .197-inch
thick steel as opposed to .157-inch on the 1500 HD
(or .106-inch on a half-ton 1500). Any difference
in frame flex is virtually impossible to detect, as
the 1500 HD frame feels much stiffer than the frame
of a 1998 one ton. The rear GAWR on the 2500 HD is
6,084 pounds as opposed to 6,000 on the 1500 HD. Subtract
the empty weight and both trucks have approximately
3,400 pounds of load capacity available on their rear
axles. Tires, wheel base, springs and shocks are all
identical, so there is no safety advantage with the
2500 HD.
One interesting thing I did discover when researching
this is that the rear axle of the 2500 HD has weight
rating of 6,900 pounds but they keep the GAWR at 6,084
pounds, which is the limit of the tires. 265/75-16
tires have a load capacity of 6,830 pounds, so I would
not be surprised to see GM increase the tire size
and the rear axle capacity at some time, which would
be nice for those towing heavier fifths that do not
want dual wheels. We have actually done this on one
truck where the customer was running almost at maximum
load, just to give the tires some leeway in their
load capacity.
The transmission in the 1500 HD is the MT1 four-speed
automatic that GM introduced in 1992 and has refined
considerably since. This transmission is capable of
handling more power than the 6.0 litre can produce.
It is one of the nicest and most reliable automatics
available, and its shift points are well suited to
towing. The first gear ratio is 2.48:1, which could
be a little lower if you had to start out on a very
steep hill, but it will always get you there. And
with a four wheel drive truck, you always have low
range for that very rare instance. The 248:1 ratio
does allow you to climb very steep hills at a little
higher speed.
The 2500 HD with the Duramax or 8.1 will certainly
climb some hills a little faster than the 6.0 litre.
However you will never save enough time on hills to
make up for the time you spend in the gas station
feeding the 8.1, and some would rather downshift once
in a while rather than listen to a diesel. Others
love the sound of that diesel hammering away up a
big grade. As diesels have become more powerful they
have lost a little fuel economy, while gas engines
have become more efficient. So diesels have lost some
of their economic advantage. If you put enough miles
on in a year then you can justify the additional cost
of the diesel. Currently, the break-even point is
about 35,000 kilometres a year.
Further, you may find that dealer incentives and
low interest financing deals apply to the 1500 HD
and not the 2500 HD. When bearing these considerations
into account, the 1500 HD may wind up being several
thousand dollars less than a 2500 HD. If you would
like a nice day-to-day truck that will also tow a
large fifth wheel, the 1500 HD is a very nice package
that is often overlooked.
If you want to do some serious, high-mileage towing
or are getting into the 13,000 - 14,000 pound dry
weight class, then a 2500 HD with the Duramax or the
8.1 litre gas would worth looking at. The heavier
rear axle would also be of some value if you are running
near the maximum load on a regular basis.
When looking for a truck, it is important to think
about your own use of the vehicle and how it will
fit with your lifestyle. I think back to not very
many years ago when we were quite limited on vehicles
and engines. Now it is great to have so many choices.
(Page Top)
|
