- When it comes to picking out a set of wheels
or rims for your Jeep, Toyota truck or SUV from TrailBuilt
there are many more things to consider
than just how they look.
Hey, what's up guys, Josh from TrailBuilt.
And it can be quite the scientific formula when picking out
the right wheel and tire combination for your rig.
There's the overall diameter of the wheel,
the inside diameter of the barrel,
the offset and backspacing, the center hub bore size,
the weight of the wheel, the overhaul width,
the section width, the bolt pattern
and even the dimensions of the different types of lug nuts
and their mounting surfaces.
That can all be very important factors
when picking out the right wheel for your rig.
So make sure and smash that subscribe button so that way
you guys can hold onto the ride with us.
Starting with the overall diameter of the wheel.
The majority of us who use our vehicles for more
practicality and functionality over form,
especially for off-road purposes are going to stay in that
17-20 inch wheel diameter size range.
Some of us still prefer the 15 or 16 inch sizes
most commonly because well, one,
they are usually less expensive.
And number 2, we probably already have the tires
that only fit those size wheels,
but most of us will decide on a wheel size
because that's what the vehicle came from from the factory.
Or we already know we're gonna be going
with a larger size tire
and want to maintain a larger tire sidewall.
Or as I like to refer to it as, more meat on the bones.
Having a larger tire sidewall will help reduce damage
from trail obstacles, rocks, or other hazards
from being done to the wheels, especially on hard impacts.
And it also really helps with allowing the tire
to flex and envelope over the rocks and trail obstacles,
when air down to gain additional traction.
Plus a larger sidewall will help cushion
some of the harsh bumps and cracks in the pavement
or while out in the trail, allowing for a smoother ride.
A good rule of thumb is, if you're gonna go
with a larger size wheel and tire combo,
is to not go any smaller in the wheel diameter
than what your rig came with from the factory,
as you might run into some clearance issues with the wheel
not fitting over the brake caliper
or even possibly over the tie rod ends.
If your vehicle came with 17s,
well then 17s or bigger is a safe choice for fitment.
If it came with 18s, well then 18s and bigger.
And you guys get the point as the general rule of thumb
when picking out the wheel size.
Cost also becomes a factor with wheel and tire sizes.
So keep that in mind.
And typically the larger the wheel
the more expensive it becomes
and same principle applies to the tires as well.
A few more items that we'll get into a bit further
in this video is how the size of the wheel
and tire package increases the weight of the wheel
and tire combo and the handling and performance of your rig.
And how, in some circumstances, even the same size wheel
that your vehicle came with from the factory,
might not even fit.
And we'll talk about that a little further in the video.
The offset of a wheel is the distance,
measured in millimeters, from the wheel hub mounting surface
to the center line of the wheel.
And will be one of three different measurements.
Zero offset which means the wheel mounting surface
lines up exactly with the center of the wheel itself.
Then positive offset, and that is the hub
or the wheel mounting surface is located
in the front section of the wheel,
somewhere between the center of the wheel
and the outer part of the wheel.
Having a positive offset will tuck in your wheels
and tires more towards the frame of the vehicle
and are more commonly found on passenger cars, crossovers
and SUV's of which it is important to know
what your factory offset is,
before purchasing your next set of wheels.
And negative offset means that the wheel
or hub mounting surface is more
in between the back half section of the wheel,
behind the center line of the wheel.
Having a negative offset will push your wheel
and tire out away from the vehicle,
giving you a wider stance or more poke of your tire.
Contrary to how it sounds, you would think a positive offset
would push your wheels and tires out from the vehicle
and a negative offset would suck them in
or tuck them in towards the frame.
But, and I'm not sure as to why yet, it's just the opposite.
Negative offset pushes out
and positive offset sucks them in.
The best way to find out what your factory wheels offset
is by removing the wheel from your vehicle
and searching the backside of one of the wheels spokes
for the ET number.
ET is a German word that I'm not even gonna attempt
to try to pronounce,
it's something like, einpresstiefe
but in English it translates to insertion depth.
The ET number which will either have a minus symbol
in front of it, which means it has
a factory negative offset, or it says ET
and then a zero or ET and a double digit number,
which means the wheel has a positive offset to them.
Backspacing is easily measured with the front of the wheel
facing down and is the measurement from the hub
or wheel mounting surface to the inner flange of the wheel,
where the tire bead sits.
It's not actually measured from the outer edge of the rim.
So just keep that in mind,
if you're calculating backspacing instead of offset.
And remember offset is measured out
from the exact center of the wheel
and offset measurements are much easier to calculate
once they are understood properly.
But to measure the backspacing, take a straight edge
and lay it across the inner flange
on the backside of the wheel, then take a tape measure
or ruler and place it flat on the wheel mounting surface
and measure to the straight edge.
And that will give you your backspacing measurement.
The lower the backspacing measurement is,
the more your wheel and tire is going to be pushed out away
from the vehicle and away from your steering
and suspension components as well.
Same with the negative offset measurement.
The larger the negative offset is,
the more clearance you'll gain from your tie rod ends,
knuckles, shocks and springs.
This is especially important when increasing
the size of your tires and upgrading your steering
to larger components.
When turning sharp or from full steering lock
to full steering lock, larger diameter tires
will be much more likely to hit on your
inner wheel wells, frame, leaf springs,
if you have them upfront, and even your shocks
if you are flexing out your suspension.
They'll end up hitting the upper part of the shock
unless they are inboarded far enough.
Also keep in mind that the more negative offset you have
and the more your wheels and tires are pushed out,
the more negatively it will affect your on-road handling
and performance.
And also the more wear and tear
it will put on your drive line components
like your ball joints and wheel bearings.
The more weight that is pushed outwards,
the less balanced over the bearings
that they are causing additional forces
and stress on those components.
Plus a negative offset will also change
the geometry of how the steering was designed to perform
with the factory wheel and tire setup.
Pushing the tires and wheels out will negatively impact
the caster and camber, which affects
the handling performance of your rig and will cause
more wear and tear on the expensive tires you just bought.
So it's really important to make sure
and get an alignment performed as soon as the new wheels
and tires are installed to adjust the tow caster
and camber to perform well with the new setup.
So make sure and check out our fitment gallery first,
if you're not sure on what offset you might need.
Plus we also have a wheel and tire calculator
on our homepage and we'll link that in the description
but you can use that to compare
your stock wheel and tire combo
with the desired wheel and tire size upgrades.
And it will also give you an idea
of what the size comparisons between the two are.
So just remember to keep in mind that when you are
increasing your tire size or changing your offsets
to allow additional clearances for that larger tire,
including when steering from full lock to lock
or side to side, and when flexing out.