California’s modern smog-check program dates back to the 1980s. Over the decades, updates imposed biennial emissions inspections on all 1976-and-newer vehicles, requiring tailpipe or onboard-diagnostics (OBD) testing before registration renewal. Vehicles older than 1976 are generally exempt. That cutoff has remained frozen, creating a longstanding tension between regulatory goals and the collector-car/hot-rod community.
The push to modernize this framework emerged in early 2024 with Senate Bill 712, introduced to create a 35-year rolling smog exemption. Instead of a permanent 1975 cutoff, vehicles would gradually age out of smog inspection requirements once they reached 35 years old, aligning California more closely with other states. The proposal quickly earned the nickname “Leno’s Law,” thanks to public support from Jay Leno.
SB 712 moved through early committee hearings and garnered enthusiasm from hobbyists and parts of the collector-car industry. At the same time, environmental groups and fiscal committees raised concerns about emissions impact and regulatory precedent. Amendments were proposed that would have narrowed eligibility, including additional documentation and collector-vehicle definitions. By mid-2024, SB 712 stalled in committee and ultimately failed to advance before the legislative deadline.
This was not an isolated attempt. Over the past decade, enthusiasts and industry groups like SEMA have repeatedly sought to expand the smog exemption to a rolling system. The frustration has been consistent: California’s regulations are strict, and older collector vehicles are subject to perpetual inspections unless legislative change occurs.
Now, the concept has returned as Senate Bill 1392, and it retains the same premise as the original: a 35-year rolling exemption that allows qualifying vehicles to age out of smog inspections once they cross the threshold. Supporters argue that these vehicles account for a tiny fraction of total miles traveled and are typically maintained and driven sparingly…