San Diego is beautiful, but it is rough on tires. Here is why we handle flat tire calls every day.
Construction debris on I-5 and I-15
San Diego County has been in near-permanent highway construction since the mid-2000s. The I-5/I-805 merge, the SR-163 interchange, the ongoing I-15 expansion through Escondido, all shed nails, screws, and metal fragments onto the roadway. The stretch of I-5 through Sorrento Valley and Del Mar is particularly bad.
Pothole season after winter rain
San Diego does not get much rain, but when it does, the roads fall apart. City Heights, Encanto, Southeast San Diego, older National City, potholes form quickly. A pothole hit at 35 mph can blow out a sidewall instantly. January through March is peak season.
Sharp rocks and gravel near trails
Trailheads at Mission Trails, Torrey Pines, Cowles Mountain, and the back roads toward Julian mean loose gravel and sharp decomposed granite. Highway tires are not built for this. Iron Mountain, Potato Chip Rock, Sunset Cliffs lot, regular flat-tire pickup zones.
Old tires that look fine
San Diego's mild climate means tires do not show obvious wear. But UV exposure and heat cycling degrade rubber. Tires older than 6 years are at increased blowout risk regardless of tread depth. Check the four-digit DOT code on your sidewall, "1718" means week 17 of 2018.