The California Lemon Law Mileage Offset, Explained

The mileage offset is the single biggest deduction from a California lemon law buyback, and it's calculated by a fixed formula: your vehicle's purchase price multiplied by the miles you drove before your first repair visit for the defect, divided by 120,000. Everything else in a buyback is a refund to you — the offset is the one amount the manufacturer keeps, to account for the use you got out of the car before the problem showed up. Understanding it tells you roughly what your buyback will actually come to.

The formula

Mileage offset = purchase price × (miles at your first repair visit for the defect ÷ 120,000). The 120,000 figure is set by statute — California assumes 120,000 miles of useful life. So the offset is simply the share of that useful life you'd already used up when the defect first sent you to the dealer.

An example

Say you paid $40,000 for the vehicle and first brought it in for the defect at 12,000 miles. The offset is $40,000 × (12,000 ÷ 120,000) = $4,000. So the manufacturer would refund what you paid, then subtract $4,000 for those first 12,000 miles. If you first brought it in much earlier — say 3,000 miles — the offset would be only $40,000 × (3,000 ÷ 120,000) = $1,000. The earlier the defect appeared, the smaller the deduction.

Why only your early miles count

This is the part owners most often get wrong, and it works in your favor: only the miles you drove before your first repair attempt for the defect count toward the offset. Every mile you put on the car afterward — while the manufacturer was failing to fix it — does not increase the deduction. That's deliberate. You shouldn't be penalized for continuing to drive a car you paid for while the manufacturer couldn't repair it. So if your defect appeared early and dragged on through many repair visits, your offset stays small even as your total mileage climbs.

What the offset doesn't touch

The offset only reduces the price portion of your refund. It doesn't reduce the other things a buyback returns — your taxes, registration and license fees, finance charges, and incidental costs like towing and rental are still refunded in full. And it has nothing to do with any civil penalty: if the manufacturer acted willfully, you may recover up to two times your damages on top of the buyback, and the offset doesn't shrink that.

Want a rough number for your own vehicle? Our free California lemon law buyback calculator applies this exact formula — enter your price, payments, and the mileage at your first repair for an instant estimate.