Updated April 5, 2026 — Prices updated regularly from EIA data
Route • 1 states
About Interstate 405
The San Diego Freeway running 72 miles through metro Los Angeles from San Diego to San Fernando Valley, I-405 is one of the most congested interstates in America. Gas prices along I-405 reflect California's 67-cent fuel tax — the highest in the nation.
Interstate 405 passes through or near major cities where competitive fuel markets and warehouse clubs offer the best prices. Look for Costco, Sam's Club, or high-volume discount stations in each major metro along your route.
A 2-mile detour to save 20 cents per gallon on a 15-gallon fill-up saves $3. With a car getting 28 MPG, the detour uses 0.14 gallons. Detours above 3-4 miles for savings under 20 cents per gallon are generally not worthwhile.
The cheapest gas along Interstate 405 is generally found in California, where lower fuel taxes and proximity to refineries or pipelines keep prices down. Avoid fueling at highway-exit stations in California, where tourist premiums push prices 15-25 cents above the best nearby rates.
For a trip along Interstate 405, a vehicle averaging 25 MPG would use approximately 1 gallon per 25 miles. At current average prices along the route, budget approximately {perMileCost} cents per mile for fuel. Plan fill-ups in lower-price states whenever possible.
Yes — consistently. Highway-exit gas stations charge 10-25 cents more per gallon than stations just 1-2 miles off the interstate. Whenever possible, exit the highway and drive to a commercial area for competitively priced fuel.