SKU: 40659 | UPC: 808422406598
Borla 40659 ProXS Muffler – 2.5in Offset Inlet / 2.5in Center Outlet 4.25 x 7.88 Oval x 14in Long Body
The Borla 40659 ProXS Muffler is a universal performance part with a 2.5-inch offset inlet and 2.5-inch center outlet in a compact oval body measuring 4.25 x 7.88 inches by 14 inches long overall 19 inches. Designed for custom exhaust builds on cars, trucks and SUVs where space is tight, it installs with flexibility thanks to its reversible configuration. Gain power, torque, better fuel economy and the signature Borla Sound of Power that excites with every throttle press.
Key Features
- Compact Dimensions: 4.25in height x 7.88in width x 14in body length (19in overall) fits tight spaces without compromising flow or sound.
- Reversible Design: Offset inlet/center outlet swaps for straight-forward installation in any custom setup.
- T-304 Stainless Steel: High-grade material resists rust and corrosion for long-lasting durability in all conditions.
- 100% Welded Construction: Ensures structural strength and leak-free performance under high heat and pressure.
- Free-Flow with CFF Acoustic Core: Boosts horsepower and torque while controlling drone for a refined, aggressive exhaust note.
Product Notes
- Universal fit for 2.5-inch piping; reversible for inlet/outlet orientation.
- Natural mill finish ready for brushing or polishing before install.
- Ships in protective packaging; weight 10.8 lbs.
Installation Notes
- Professional installation recommended.
- Clamp or weld to 2.5in piping; reversible design simplifies routing.
- Compatible with standard exhaust hangers and hardware.
This Part Fits
| Year | Make | Model | Submodel |
|---|---|---|---|
| Universal | All | All | 2.5in Custom Exhaust |
Why Choose Borla?
- Leaders in stainless steel exhaust since pioneering systems for classics like Ferrari and Rolls-Royce.
- Engineered for power gains, torque increases and fuel efficiency in street, off-road and racing.
- Builds more than parts—delivers throttle rush and heart-pounding soundtrack every drive.
Frequently Asked Questions
- Q: Does this muffler fit specific vehicles?
A: Universal design works with any 2.5in exhaust system; reversible for custom routing on cars, trucks or SUVs. - Q: What material is used and does it rust?
A: T-304 austenitic stainless steel provides rust resistance and maintains finish under extreme conditions. - Q: What warranty applies?
A: Backed by Borla’s million-mile warranty when installed per guidelines on qualifying systems.
Shipping & Handling
- Method: UPS Ground or FedEx
- Availability: In stock – ships same or next business day
- Packaging: Secure box 22in x 10in x 10in
- Weight: 10.8 lbs





Reviews
There are no reviews yet.