Mazda 626 Dome Light Bulb Size

Additional Notes

• The DE3175 is a festoon-type bulb with a 31mm length and end-cap contacts, operating at 12V. Festoon bulbs seat horizontally between two spring-loaded contact points rather than inserting into a socket.
• The Mazda 626 uses the DE3175 as its dome light bulb across the majority of its model years, spanning 1983-1991 and 1993-2002, making it the dominant bulb type in these specifications.
• The 6428 is also a festoon-type bulb, though it is 36mm in length and uses an SV8.5 base, operating at 12V and 5W. The SV8.5 base designation refers to a specific contact cap style used in European-origin festoon bulbs.
• Although both the DE3175 and the 6428 are festoon bulbs, their differing lengths (31mm versus 36mm) and base types mean they are not interchangeable with each other.
• The Mazda 626 from 1979-1982 uses the 6428 bulb for the dome light, which reflects an earlier fitment standard before the DE3175 became the specified type.
• The 194 is a miniature wedge bulb of the T10 form factor, rated at 12V and 3.78W. Wedge bulbs use a pinched glass base as the contact rather than a cap or end-clip, and they insert directly into a wedge-type socket.
• The 194 wedge bulb is specified only for the 1992 Mazda 626 dome light, while the surrounding model years carry the DE3175 festoon specification, indicating the 194 is not a cross-year substitute.
• All three bulb types in these specifications conform to ANSI standards applicable in the United States and Canada, meaning they share a common regulatory framework for electrical and dimensional tolerances.