Upgrades
Reviews
As with anything in life there are tradeoffs when it comes to selecting tires for your vehicle. Whether the tires are bridgestone, goodyear, or Michelin tires, different sizes and treads can offer different benefits as well as downsides.
What Fits and What Hits*
Wrangler (YJ)*
(TJ's May use up to 1" larger tire on street)
Tire Size
(Diameter)
| Suspension
Modifications
| Body Lifts
| Fender Trimming
|
|---|
| 30" | No lift required -
however small lifts will
increase articulation
greatly | No lift required -
however a 1" or 2"
body lift could be used
to increase articulation | No trimming required
and none
recommended |
| 31" | No lift required for
street use but there
may be some slight
plastic fender rubbing.
2" to 3" lifts are
recommended for trail
use to increase
articulation | No lift is required but a
1" or 2" body lift can
be used in place of a
suspension lift to gain
clearance and eliminate
rubbing | No trimming is
required and none is
recommended |
| 32" | A 2" to 3" lift would be
recommended, a 4" lift
would provide greatly
increased articulation
without rubbing | A 2" body lift
combined with 1" lift
extended shackles
could be used to clear
this size on an extreme
budget. | With extended
shackles or small
suspension lifts there
may be some rubbing
at the corners of the
plastic fenders under
extreme conditions. |
| 33" | A 4" suspension lift or
spring over conversion
is recommended. | A 1" or 2" body lift is
recommended to
increase clearance | Some rubbing may
occur Some trimming
of the bottom trailing
edge of the rear fender
may be useful. |
| 35" | A 4" suspension lift or
spring over conversion
is necessary. Axle &
brake upgrades are
highly recommended
as well. | A 2" body lift is
recommended, a 3" lift
can increase clearance. | With a 2" body lift
trimming some fender
edges as much as 1" or
2" may be needed. |
CJ*
Tire Size
(Diameter)
| Suspension
Modifications
| Body Lifts
| Fender Trimming
|
|---|
| 30" | No lift required -
however small lifts will
increase articulation
greatly | No lift required -
however a 1" or 2"
body lift could be used
to increase articulation | No trimming required
and none
recommended |
| 31" | No lift required for
street use as this is
close to stock size. 2"
to 3" lifts are
recommended for trail
use to increase
articulation | No lift is required but a
1" or 2" body lift can
be used to gain
clearance and
articulation | No trimming is
required and none is
recommended |
| 32" | A 2" to 3" lift would be
recommended, a 4" lift
would provide greatly
increased articulation
without rubbing | A 2" body lift
combined could be
used to clear this size. | No trimming is
required unless rubbing
is actually observed in
use. |
| 33" | A 3" to 4" suspension
lift or spring over
conversion is
recommended. | A 1" or 2" body lift
may be used to
increase clearance | Some rubbing may
occur Some trimming
of the bottom trailing
edge of the rear fender
may be useful. |
| 35" | A 4" suspension lift or
spring over conversion
is necessary. Axle &
brake upgrades are
highly recommended
as well. | A 2" body lift is
recommended, a 3" lift
can increase clearance. | Some trimming of
fender edges may be
needed to eliminate
rubbing problems |
Cherokee (XJ & ZJ)*
Tire Size
(Diameter)
| Suspension
Modifications
| Body Lifts are not
available.
| Fender Trimming
|
|---|
| 30" | No lift required -
however small lifts may
increase clearances &
articulation | N/A | Some minor fender
trimming may be
required if rubbing is a
problem with wider
tires |
| 31" | 3" lifts are possible, 4"
lifts would be better
for trail use. | N/A | Trimming may be
required with wider
than stock tires |
| 32" - 33" | A 5" or larger lift is
required. | N/A | Some trimming is
required |
| 33"-35" | A 6" or larger
suspension lift is
required | N/A | Serious trimming may
be required |
* IMPORTANT NOTE:
The above tables are only guidelines reflecting popular trends or upgrade combinations. Other combinations are
possible, for example: I know of a YJ owner who uses a 3" body lift and a set of 1.5" lift Con-Ferr extended shackles
to clear 33" tires. This is not what I would run or recommend - but it works for him. Your mileage may vary and we
do not claim that the above is the definitive word of god on the subject of tire clearance. Some other combinations
may work fine or on some vehicles the guidelines shown above may not apply.
Tradeoffs - Tire Size (diameter)
As with anything in life there are tradeoffs when it comes to selecting
tires for your vehicle. Increasing tires size can greatly increase the
off-road capabilities of your vehicle. Larger tires provide increases
in total ground clearance, an increased traction footprint &
flotation, make climbing obstacles easier, can be easier on the
environment and just plain look better on your Jeep. However all of
these benefits have a price.
Larger tires are more expensive in general and may require expensive
suspension upgrades for proper clearance, especially on the trail.
Tires more than an inch or two larger than stock may require you to
change the ring & pinion gears in the differentials of both the
front and rear axle in order to keep your engine running in the
optimum power range - especially when off-road, going uphill or
driving on the freeway.
Increased tire diameter increases the torque loads on the axles,
u-joints & drive shafts. For significantly larger tires it is
usually necessary to upgrade these components, especially where
traction aiding devices such as lockers or limited slip is used,
or you may risk breaking one of these components on the trail.
Bigger tires are heavier tires. This increased rotating mass and the
increased leverage provided by the larger tire often call for increases
in braking power: changing brake pad materials, rear disc brake
conversions, beefing up the master cylinder or even switching to
larger disk and calipers are all options. Driving a tall, heavy,
modified short wheelbase Jeep with 35" tires and stock brakes
in poor condition at highway speeds can be a recipe for disaster!
Increases weight caused by the larger tire and any axle or brake
upgrades also increases unsprung weight. This does not matter much
on the trail, but can make the ride a higher speeds much more harsh.
When mounting the tire you will find that it is often much more
difficult to balance the tire correctly. This is due to the extra
weight of the tire, the increased rotating inertia of the tire and
manufacturers tolerances on larger tires. It can take quite a bit
of weight to balance a large tire and many shops that do not routinely
handle tires of this size may not do a good job.
So - bigger tires have a price, the bigger the size change the more
modifications are needed to properly set up your Jeep; still, on the
trail, there are times when putting more rubber on the ground, or
more space between the vehicle and the ground, is exactly what you
need.
On my 1990 Jeep YJ I decided to switch from 31" tires to 35"
tires while not wanting to risk breakage on the trial. The total price
of those 4 35" tires was probably close to $7,000 dollars!. This
included a 4" suspension lift, a 2" body lift, fender
trimming, changing to heavy duty, custom modified, 1 ton truck axles,
changing to 4.10 gears in both differentials (+ lockers and carrier
changes), and adding rear disk brakes. In addition the lift and axles
necessitated transfer case modifications and custom drive shafts in both
ends. It was not a simple, cheap or fast project - but on the trail it
sure is sweet!
Trade-Offs Tire Size (width)
Tire diameter is not the only issue - tire width is important to. Wider
tires increase footprint which can be important for traction or
increased flotation. The tradeoff include that wider tires can also
require extended fender coverage in many states and may require changes
in wheel width & offset to work properly. On stock offset wheels
the tires may be mostly covered by the stock fender flares but rub on
suspension components when turning thus reducing effective turning
radius. The incredibly tight turning radius of a jeep is one of it's
important advantages on the trail. Wider wheels or wheels with
increased offset move the tires outboard and can greatly reduce the
rubbing when turning but make the vehicle wider. This increased width
may be an advantage for stability if you drive a lifted vehicle or a
disadvantage of you are squeezing down a trail better suited for a
Samurai or a quad. Lastly narrower tires can sometimes be an advantage
where the best traction is located just a few inches below the surface
(such a shallow snow or mud) and the decreased footprint and increased
pressure aids the tires in getting down to where it can get a bite.
Tread Patterns
The choice of tread pattern is important in your new tire decision
making process. Tread pattern should be chosen based on the intended
use of the Jeep. The most popular tread pattern for all around
off-road use is a mud terrain pattern.
The mud terrain or mud tire pattern is characterized by large lugs on
the tire with large voids between these lugs. The large lugs provide
plenty of bite in low traction conditions while the large voids allow
the tire to clean itself by throwing off mud or other material when
spinning thus providing a good bite on every rotation of the tire.
These tires are also very popular for rock crawling as the large lugs
can provide a way of gripping and pulling the tires up and over
irregular rocky edges where a smoother pattern would just spin. The
biggest disadvantage of these patterns is that they run rough and
loud on the highway. To reduce this problem choose a tire with
irregular or asymmetric spacing of the lugs and voids to reduce
harmonic vibration at highway speeds. There are also situations such
cold powder snow or sand where an all-terrain pattern would be
better.
The general purpose all terrain tire generally has an interlocked
tread pattern with siping (small cuts) on the tread blocks. The voids
in these tires are also generally much smaller than those on tires
designed for use in the mud. The denser pattern of blocks and smaller
voids make these tires quieter on the street. It also increases
the surface area of the tread which gives the tire improved flotation
on surfaces such as light powdery snow or sand. The increased siping
can be important in snow were it is the number of edges, even quite
small edges, biting into the snow that provides the "bite".
The downside is that the smaller voids cannot clean themselves as
easily of packed mud or slush as the larger voids on mud tires do. If
these voids fill up with mud the tire loses much of it's
"bite" and traction is lost.
While the all terrain pattern's improved flotation and additional
siping may be an advantage in absolutely dry powder or packed snow,
the mud terrain may be the wiser choice if the snow or underlying
terrain is, or can turn, slushy or muddy. In these cases the all
terrain pattern can become packed with mud and stuck where a
mud terrain pattern would self clean and plow on through.
In sand the improved flotation provided by the dense tread pattern
of the all-terrain tires can be a distinct advantage.
A variety of manufacturers also offer a family of tires sometimes
called trail tires or something near that. These are most often tires
designed for use on light trucks or sport utility vehicles which see
most of their use on the street. They will generally be quieter, get
better gas mileage and last longer than either of the other off-road
patterns. The tread patterns are designed to provide significantly
improved comfort or performance on the street which can sometimes
compromise serious off-road capability. I personally would not
recommend them for anything other than light off-road use in dirt, on
unpaved roads or trails where you are unlikely to encounter mud,
significant rocks or other unpleasant conditions. Fortunately this
is the limit to which most of their intended market are likely to
take them.
Factory Options
Essentials
