Rubber Fender Flares: Benefits, Sizing & NZ WoF Rules
Rubber fender flares are a practical addition to 4WDs, utes and other vehicles fitted with wider wheels or tyres. They extend the coverage of the original wheel arch, helping contain mud, stones, water and other debris thrown up by the tyres.
They can also provide the additional tyre-tread coverage needed when aftermarket wheels or a different wheel offset cause the tyres to sit outside the factory guards.
In this guide, we explain what rubber fender flares are, why they are commonly fitted, how to choose the correct size and what New Zealand vehicle owners need to consider before a WoF inspection.
What Are Rubber Fender Flares?
Fender flares are extensions fitted around a vehicle’s wheel arches. They increase the width of the guard so that more of the wheel and tyre is covered.
Flares can be made from rigid plastic, fibreglass, steel or flexible rubber. Rubber wheel arch flares are a popular choice for 4WDs because they can be shaped around different wheel-arch profiles and trimmed to the required length.
Unlike vehicle-specific moulded flares, universal rubber flares can suit a wide range of vehicles. This makes them useful for older 4WDs, custom builds and vehicles where replacement factory flares are difficult to find.
Why Fit Rubber Wheel Arch Flares?
There are several reasons to install rubber fender flares.
Additional tyre coverage
Aftermarket wheels, wider tyres and changes in wheel offset can cause the tyre tread to extend beyond the original bodywork. A correctly sized flare increases the width of the wheel arch and can provide the additional coverage required.
Protection from stones and mud
Tyres can throw stones, mud, water and other debris against the doors, guards and lower body panels. Rubber wheel arch flares help intercept this material before it reaches the vehicle’s paintwork.
This can be particularly useful on 4WDs regularly driven on gravel roads, muddy tracks, farms or off-road terrain.
Flexibility for off-road driving
Rubber flares flex when they make contact with branches, banks or other obstacles. This makes them less likely to crack than some rigid plastic or fibreglass flares.
Their flexibility makes them well suited to vehicles used away from sealed roads.
Replacement for missing factory flares
Original flares for older vehicles can become brittle, damaged or difficult to source. Universal rubber fender flares offer a straightforward alternative that can be cut and shaped to suit the existing wheel arches.
A wider, finished appearance
Flares can also improve the appearance of a vehicle fitted with wider wheels and tyres. They help visually connect the wider wheel position with the vehicle’s bodywork, giving the modification a more complete finish.
Rubber Fender Flares and NZ WoF Requirements
For a New Zealand WoF, a vehicle’s body panel, mudguard or wheel arch flare must cover the full width of the tyre tread. The tyre tread is the portion of the tyre that contacts the road; it is not necessarily the widest point of the tyre’s sidewall.
Modified mudguards and added wheel arch extensions generally do not require separate LVV certification when:
- The original mudguard has not been cut
- The flare or extension has no sharp protrusions
- The extension is securely attached
- The completed mudguard remains no less effective than the original equipment
The flare must also be in safe condition and must not present a hazard to other road users.
Check your proposed wheel, tyre and flare combination with a WoF inspector or LVV certifier when you are uncertain about the requirements.
Does the Tyre Sidewall Need to Be Covered?
The NZTA inspection requirement refers to the full width of the tyre tread—the part of the tyre that contacts the road.
A rounded or bulging sidewall may sit slightly outside the flare while the tread remains covered. When checking the required width, look at the outer edge of the tread rather than simply measuring to the widest point of the tyre.
Your WoF inspector will make the final assessment, so it is sensible to allow a small amount of additional coverage rather than choosing a flare that only just reaches the tread.
How to Choose the Correct Flare Width
To select the correct rubber wheel arch flares, measure horizontally from the edge of the original guard to the outer edge of the tyre tread.
Choose a flare that covers this distance while allowing a small margin.
How Much Rubber Flare Do You Need?
Measure around the outer edge of each wheel arch where the flare will be installed. Add the measurements together and allow extra material for trimming and final adjustment.
The amount required varies between vehicles. Larger wheel openings, square arches will require more material than a small vehicle with rounded arches.
Installing Rubber Fender Flares
Rubber fender flares are positioned along the inner edge or underside of the wheel arch and held in place using mounting plates and fasteners.
Before installation:
- Clean the mounting area and remove loose dirt or damaged trim.
- Hold the flare against the wheel arch and confirm the required position.
- Check that the flare covers the tyre tread when viewed from above.
- Mark the required length before cutting.
- Space the mounting plates evenly to maintain a consistent shape.
- Check behind the mounting surface before drilling or installing fasteners.
Be aware of wiring, hoses, plastic liners and double-layered body panels behind the guard. Installation methods vary between vehicles, so professional fitting may be worthwhile where the mounting area is difficult to access.
Rubber Flares Compared With Rigid Flares
Rubber and rigid fender flares can both provide additional wheel coverage, but each option has different advantages.
Rigid moulded flares can provide a factory-style appearance when a vehicle-specific kit is available. However, they may be more expensive, harder to adapt and more likely to crack.
Universal rubber fender flares are flexible, can be cut to length and can fit a broader range of wheel arches. They are especially useful for custom applications or older vehicles without readily available model-specific flares.
The best option depends on the appearance you want, how the vehicle is used and the amount of tyre coverage required.
Shop Rubber Fender Flares in NZ
Flatout Offroad supplies flexible rubber fender flares in several coverage widths. Our flares are sold by the meter, allowing you to order the length required for your individual vehicle.
Mounting plates and self-tapping fasteners are included, with additional mounting support supplied for our widest flare option.
Browse our range of rubber fender flares or contact us with a photo and measurements if you need help selecting the most suitable size.
We ship throughout New Zealand and can send international orders using DHL Express.