Common Questions

Have a questions regarding EFX Tires?  We put this page together to help educate our customers, dealers and even new members to the EFX Family on best practices when dealing with tire specs.  If you feel we missed anything on this list or still have a question that needs a clearer answer, feel free to call us and we will do our best to help where we can (800) 734-4890

The diameter of the tire is not the same as the height of the tire. The height of the tire is the sum of the radius of the top half of the tire, and the static loaded radius of the bottom half of the tire. The static loaded radius is going to be different depending on how much air is in your tire, and how much your vehicle weighs. So…. what does this all mean?

The weight difference between (for example) any stock Polaris Sportsman ATV and stock Polaris Ranger UTV, will vary dramatically. Added weight will affect your tire’s overall dimensions. If you inflate your EFX Tires with less air pressure than sidewall recommendations, the tire will not measure true to sidewall overall diameter (OD). Each of our EFX Tires have a specified recommended PSI, and if you add less, or more air than suggested, your OD will vary. Please take these variations under considerations when measuring dimensions of your tires.  In short, we recommend measuring your tire with recommended sidewall air pressure and NOT under load of vehicle.

The R in the sidewall size, for example 32-9.5x14R, identifies that the tire has a Radial construction in which the tire’s body plies “radiate” out from the imaginary center of the wheel. Radial tires improve handling and safety of vehicle as well as drastically improving weight balance of wheel and tire combo resulting in a smoother ride.

The shape of a tire’s contact patch or “footprint” greatly influences its performance and is dependent on its profile or “aspect ratio”. Tires with large contact patches are effective in converting the driver’s input into very responsive handling, cornering stability and traction. Larger tread heights or larger space between lugs (small contact patch) results in less contact to terrain and less overall handling.

One of the main rubber components is the tread compound, which is typically manufactured by extruding, a process that’s essentially an industrial version of squeezing toothpaste out of a tube.  In the case of tires, warm rubber is extruded through a metal die to produce a continuous slab of tread rubber compound that’s the appropriate width and thickness for the tire size being manufactured. The slab of tread rubber compound is subsequently cut to the length needed to go exactly one revolution around the tire’s circumference.

Since thousands of these flat tread slabs are processed in our manufacturing facility every day, we often print stripes (often featuring multiple stripes or various colors around the tire’s circumference) to identify the exact type and size tire for which the tread slab is intended. Because the tread identifying stripes/letters/numbers are printed on the flat tread slab before the tire is assembled and its tread design is molded, these identifiers can be seen on the surface of a new tire’s tread blocks, as well as all of the way down to the bottom of the tread grooves.

Correct tire inflation pressure allows drivers to experience tire comfort, durability and performance designed to match the needs of their vehicles. Tire deflection (the tread and sidewall flexing where the tread comes into contact with terrain) will remain as originally designed and excessive sidewall flexing and tread squirm will be avoided. Heat buildup will be managed and rolling resistance will be appropriate. Proper tire inflation pressure also stabilizes the tire’s structure, blending the tire’s responsiveness, traction and handling.

If a vehicle’s tires are underinflated by only 5 psi it could lead to tire failure. Additionally, the tire’s tread life could be reduced by as much as 25%. Lower inflation pressure will allow the tire to deflect (bend) more as it rolls. This will build up internal heat, increase rolling resistance and cause a reduction in fuel economy of up to 5%. You would experience a significant loss of steering precision and cornering stability.

An overinflated tire is stiff and unyielding and the size of its footprint in contact with the road is reduced. If a vehicle’s tires are overinflated by 5 psi, they could be damaged more easily when coming into contact with rocks, obstacles or sharp objects. Higher inflated tires cannot isolate terrain irregularities, causing them to ride harsher. Your tire pressure will vary throughout the life of your EFX tires.  We suggest checking with a quality air gauge as the inflation pressure cannot be accurately estimated through visual inspection.

The load range/ply rating branded on a tire’s sidewall identifies how much load the tire is designed to carry at a specified air pressure (PSI). The higher the load rating, the more weight a tire can handle in motion.  We over engineer most of our EFX Tires to ensure that no matter how much you load on your ATV, UTV or Golf Cart, your tires can handle it.  ALL EFX TIRES ARE INTENDED FOR OFF ROAD USE ONLY, NHS.

All EFX Tires feature tire/rim protectors using several different designs, including raised ribs adjacent to the bead area on their lower sidewalls or a deeply recessed bead area to partially envelop the wheel flange (lip).

Tires featuring the raised rib adjacent to the bead or the deeply recessed bead area are designed to help protect your stock or custom wheels from debris, as well as resist damage inflicted by rocks, tree stumps and other off-road obstacles. They are intended to sacrifice themselves in order to protect the tire’s internal sidewall structure and the wheels upon which they are mounted.