v3.25.2
Research, Development and Engineering (Tables)
 6 Months Ended
Jun. 30, 2025
Research and Development [Abstract]  
Summary of Research, Development & Engineering Activities Such costs are included in Cost of goods sold as follows:
Three Months Ended
June 30,
Six Months Ended
June 30,
2025202420252024
(Dollars in millions)
Research and development costs$47 $46 $90 $89 
Engineering-related expenses, net of customer (reimbursements) (1)
(2)(5)(5)(4)
$45 $41 $85 $85 
(1)    Engineering-related expenses include customer reimbursements of $13 million and $16 million for the three months ended June 30, 2025 and 2024, respectively, and $25 million and $24 million for the six months ended June 30, 2025 and 2024, respectively.