- Having a complete and total understanding
of everything relating to your truck's tires' performance
when hauling heavy loads
is crucial to arriving at your destination safely.
So with that said,
how do we know what load rating is best
for our own particular application?
Well guys, let's find out.
Basically, a tire's load rating directly impacts
a vehicle's carrying capacity.
Passenger tires and light truck tires
have different load ratings
based on a combination of factors like size,
construction, application and inflation pressure.
In the United States, the Tire and Rim Association,
or TRA, is the standardization organization for tires
and publishes an annual yearbook
with load and inflation tables for each tire size
and load rating, plus the maximum tire's air pressure,
which is listed on the sidewall of the tire as well.
Load and inflation standards have been developed
over the years,
taking into consideration
the size of the tire's air containment chamber,
inflation pressure and tire usage.
Additionally, load provisions are specified
for tires designed with reinforced constructions,
typically described as XL or extra load tires for passenger
or higher load range symbols
for light truck designated tires.
And it's always best to refer to the tire sidewall markings
for the size maximum load rating
and air pressure information.
Tire size is another major factor in determining
the load carrying capacity.
So when you're searching for different tire sizes
on our website at TrailBuilt Off-Road,
you'll notice that there are
three different tire size designations.
Tire sizes typically used on OE or original equipment tires
for light duty trucks are P-metric, LT-metric
and Euro-metric.
Many quarter and half-ton trucks will use the P-metric
and Euro-metric standards,
whereas three-quarter ton, and one ton trucks will use
the LT-metric sizes.
In addition to being used on light duty trucks,
P-metric is a global term and is used around the world.
The P stands for passenger and is found on sedans, coupes,
minivans, small SUVs, CUVs and some lighter duty trucks.
P-metric tires are often broken down
into additional categories,
standard load or SL, extra load, XL.
Standard load tires are intended for normal, everyday use
and will either be marked with SL after the tire size
or not marked at all.
Extra load or XL tires are designed to be able to carry
a higher load than standard load tires.
LT-metric is also pretty common and will have the letters LT
in front of the tire size molded on the sidewall
and are found on pickup trucks.
Light truck tires can carry heavier loads
due to a higher maximum inflation pressure,
which varies depending on the load range,
and will also have a different construction
than P-metric tires, including a deeper tread depth.
Trucks or overlanding-type vehicles
that will be carrying a bunch of extra weight
are going to require tires with a higher load range
in order to handle all that extra weight.
The load range is an indicator of a tire's strength
and defines the tire's load carrying capacity
and inflation pressure
with an ascending letter of the alphabet
with the most common being B, C, D, E and F
load range ratings.
It's also important to ensure
the maximum gross vehicle's weight rating, or GVWR,
which is referenced on the vehicle's place card
or in the owner's manual,
is less than what the tire's load range weight rating is.
If the tire size changes,
the new size must have an equal or greater
load carrying capacity
versus the original equipment place card size.
And if that's the case, the TRA even goes as far as
recommending you to contact the vehicle's manufacturer
for the weight carrying guidelines with the new tire size.
Another thing to note with weight carrying capacity is that
the maximum load capacity is only that if the tire is
inflated to its maximum air pressure.
The maximum inflation pressure listed
doesn't necessarily mean it's
the recommended inflation pressure.
For example, most P-rated tires have
a maximum inflation pressure of 44 PSI
marked on the sidewall.
However, this may not be the inflation pressure needed
for the vehicle, and may only need 32 PSI.
Now let's say for example,
we're looking at a load range D tire
in the light truck category,
and it's a 265/70R17 at 65 pounds
per square inch of air pressure.
That tire has a maximum load capacity of 3042 pounds.
Combine that tire with three more, and now with those tires,
your vehicle, including the weight of the vehicle,
can now carry a maximum of 12,168 pounds
with all four tires set at 65 PSI.
Tire ply ratings are a throwback to the old system
when bias ply truck tires were prevalent
and measured a truck tire's carrying capacity
by the number of plies in the carcass or body of the tire.
Now it's just a rating and not the number of actual plies
or layers that the tire is made out of.
A higher numeric rating or ply count identified on tires
will feature stronger and heavier duty construction.
Today's radial truck tires will only have one steel ply
in the carcass,
but it's still used as a measure of their carrying capacity.
12-ply rated tires carry more weight than a 10-ply.
And an F load rating will be equivalent to a 12-ply rating.
An E load is 10-ply, and so on.
However, the most accurate measurement
from an engineering perspective is the load index.
The tire's load index is relative to
the maximum load carrying capacities allowed
at the maximum rated speed of the tire
indicated by the speed symbol,
and should be referenced when applicable
as load and speed index values are more typically used
in Europe and sometimes in Canada,
but not always referenced here in the United States.
All right guys, so to sum it all up
and answer the question of,
how do we know which tire is
the best load carrying tire for us,
is knowing how much weight you're going to be hauling,
including the weight of your vehicle, first and foremost,
and then making sure the load range value adds up
to be more than your total amount of weight
or the max gross vehicle weight rating.
And don't forget to add the tongue weight of your trailer
onto your gross weight as well
if you're going to be hauling.
Also, keep in mind
that when you're on our website searching for tires
that you can search by the load rating
or the load index value
and narrow those searches with the filter option.
That'll make it much more simpler and faster
to find the right tires to buy.
And guys, if you do have any further questions,
definitely make sure and let us know in the comments below,
or even if you have any additional input
on tire load ratings, tire index ratings,
make sure and let us know.
Other than that guys, as always,
we appreciate all of you for watching
and all of your support.
I'm Josh from TrailBuilt
and we'll see you guys out on the trail.