2019 BMW Z4 Bulb Size

Decision: This page lists the common bulb sizes for a 2019 BMW Z4 to help you choose replacements that match OEM fit and function. I present the evidence and typical alternatives so you can weigh compatibility, brightness, and longevity without assuming a single best choice. Constraints: the Z4 uses different sockets front to rear and for low/high beams, so size matters more than bulb type alone. Options are shown side by side with brief interpretations of their trade-offs—stock halogen or xenon vs. LED retrofits—so you can form a hypothesis about cost versus performance. Recommendation and risks: prefer OEM-matching sizes for reliability; aftermarket upgrades can improve light but carry installation complexity and potential error. Affiliate disclaimer: some links are affiliate links, and I may earn a commission at no extra cost to you, which supports continued testing and analysis.