ALFA ROMEO GIULIA/STELVIO (2.9L QV) - PORTERFIELD R4-S BRAKE PADS

Porterfield R4-S Brake Pads — Alfa Romeo Giulia / Stelvio QV

Description

The Porterfield R4-S compound is engineered for high-performance and heavy-duty street use, offering excellent braking power with minimal pedal effort. With a friction coefficient of up to 0.41, these pads deliver consistent stopping performance in both cold and hot conditions.

Ideal for spirited driving and occasional autocross, the R4-S provides a noticeable improvement over OEM pads while maintaining quiet operation and low dust output. The compound is rotor-friendly and designed to last under demanding conditions without compromising daily drivability.

Note: Not intended for dedicated track use.

Fitment (Iron Rotors)

Front (AP1116.2)

• 2017-2025 Alfa Romeo Giulia Quadrifoglio
• 2018-2024 Alfa Romeo Stelvio Quadrifoglio
• 2024 Maserati Grecale Trofeo 

Rear (AP2043) 

• 2017-2025 Alfa Romeo Giulia Quadrifoglio
• 2018-2024 Alfa Romeo Stelvio Quadrifoglio

Specifications

• Compound: R4-S (Street Performance)
• Made in: USA

Bedding Process – R4-S Street Pads

Porterfield R4-S pads are pre-bedded at the factory. No aggressive break-in is required.

• Drive normally for the first 100 miles after installation.
• Avoid repeated hard stops (e.g., 60–0 mph) during this period.
• Early aggressive braking may glaze the pads and reduce effectiveness.
• After 100 miles of normal use, the pads will be fully bedded and ready for normal operation.

Safety Note: Always prioritize safe braking when necessary, regardless of the bedding period.