Best Mustang Wide-Body Kits: 2015-2019 Fender Flares

A Ford Mustang wide-body kit is a set of bolt-and-bond fender flares and body panels that widen the car’s track so it can swallow wider wheels and tires and take on a purposeful, motorsport-inspired stance. For the 2015–2019 S550 Mustang, the most complete way to go wide is the Anderson Composites Type-JTP fender flare kit — a 10-piece set that flares all four corners. In this guide we compare every S550 widening path we stock in our Tampa, FL shop, from a subtle 0.4-inch fender bump to a full wide-body front-end conversion, with fitment, materials, and honest pricing so you can match the kit to your build.

What is a Mustang wide-body kit?

A Mustang wide-body kit is an exterior body upgrade that adds width to the fenders and quarter panels so the car can run wider wheels, wider tires, and more aggressive offsets than the factory bodywork allows. It does not add horsepower — a wide-body is about mechanical grip, tire clearance, and stance, not engine output. On the 2015–2019 S550 Mustang, factory arches typically top out around a 275–285-section rear tire on a conservative offset before rubbing; a proper flare kit pushes that clearance out several inches per side so you can fit 305-and-wider rubber and deep-dish wheels without cutting into the tire.

There are three broad ways to widen an S550, and this guide covers all of them: a subtle fender swap (Anderson’s Type-AT fenders add 0.4 inch per side up front), a full flare kit (the Type-JTP 10-piece set that overlays all four corners), and a wide-body front-end conversion (the Type-ST fiberglass fenders and matching bumper that rebuild the nose wider). Every part in this guide is molded by Anderson Composites, one of the most recognized names in Mustang aero and body panels, and every one is in stock and ready to ship from NLP Performance.

Best Mustang wide-body kits and fender flares compared

Here is every 2015–2019 Mustang widening option we stock, ranked from the full wide-body flare kit down to the mildest fender upgrade. Prices below are current NLP Performance pricing (an extra 10% off is live on all five at the time of writing) — use the table to match the amount of width and the fitment year to your car.

Top pick: Anderson Composites Type-JTP fender flares

The Type-JTP kit is the best complete wide-body package for the S550 because it addresses all four corners in one engineered set instead of forcing you to piece together mismatched fenders and quarters. It is a 10-piece kit — front flares, rear flares, and the transition pieces that tie them into the factory lines — molded in fiberglass so it stays affordable relative to a full carbon conversion while still holding a show-quality surface once prepped and painted. This is the same style of flare you see under wide-spec drag and time-attack S550 builds running 305-section and wider tires.

The other S550 widening options

Not every build needs a full four-corner flare kit. Depending on your target look, wheel spec, and budget, one of these three alternatives may be the smarter fit. All three are Anderson Composites parts and all three are in stock at NLP Performance.

Type-JTP flares for the 2015–2017 Mustang

If you drive a pre-facelift S550, the 2015–2017 Type-JTP kit is the identical 10-piece wide-body concept molded to the earlier body lines. It fits EcoBoost, GT, and even the GT 50 Years Limited Edition, and lands slightly cheaper than the 2018–2019 version at around $4,250 with the current discount. Choosing the correct year kit is critical — the facelift changed the front fascia and fenders enough that the flares are not interchangeable between the two.

Type-ST wide-body front-end conversion

The Type-ST parts rebuild the front of the car wider rather than overlaying flares. The Type-ST fiberglass front fenders (a pair, around $1,080 with the discount) widen the front arches, and the matching Type-ST front bumper with lip — roughly $990 — completes the aggressive nose. Note the bumper explicitly requires the Anderson Type-ST fenders to bolt up correctly, so plan to buy the pair together as a system. This route is popular for time-attack and show cars that want a molded, integrated widebody nose instead of add-on flares.

Type-AT fenders for a subtle +0.4 inch of width

If a full wide-body is more than you want, the Type-AT carbon fiber front fenders add just 0.4 inch of width per side — enough to tuck a slightly wider front wheel and hint at aggression without committing to flares or bodywork. Because they are carbon fiber, they also shave weight off the nose versus the steel factory fenders, and they carry the GT350-style vent look. At around $1,440 with the discount, they are the entry point into widening a 2015–2016 S550.

How wide-body fitment, wheels, and tires work

A wide-body kit only pays off if your wheel and tire plan matches the extra width, so map the two together before you buy. The whole point of flaring the S550 is to run more tire — a wider contact patch is what actually improves mechanical grip. On a stock-arch 2015–2019 Mustang, a 275–285-section tire on a roughly +35 to +45 offset is the practical ceiling before the tire kisses the fender. With the Type-JTP flares clearing the arches several inches wider per side, builders commonly step up to 305-section rear tires (and 285–305 up front on square setups) using wheels in the 11-inch-and-wider range with lower offsets that push the face out toward the flare.

Two numbers drive the fitment: wheel width and offset. Going wider or dropping offset both push the tire outboard toward the flare lip; going to a taller sidewall pushes it up toward the arch. We always recommend mocking up your exact wheel, tire, and ride height before final bodywork, because a wide-body does not eliminate the need for correct alignment, camber, and roll clearance — it simply relocates where the rubbing point is. If you are pairing flares with a coilover drop, budget for camber arms and a fender roll on the inner lip as well.

Installation, paint, and what to expect

Installing a Mustang wide-body kit is body-shop work, not a driveway bolt-on — plan for professional prep, bonding, and paint. Fiberglass panels like the Type-JTP flares and Type-ST fenders arrive in raw gel-coat and need block sanding, test fitting, and often minor massaging to follow the S550’s body lines perfectly before they are bonded and painted to match. In our Tampa, FL shop we tell customers to budget for paint and labor on top of the part cost, and to inspect every panel the moment it arrives: Anderson Composites ships carefully, but any freight damage must be noted with the carrier at delivery to be covered.

Give the shop your final wheel and tire specs before bodywork begins so the flares can be positioned for correct clearance the first time. A quality wide-body install typically means the fenders are trimmed and rolled, the flares are bonded and blended, and the whole car is refinished as a unit so the panels disappear into the paint. Done right, an S550 wide-body is a permanent, integrated transformation — which is exactly why matching the correct year-specific kit and planning the wheel fitment up front matters so much.