California Lemon Law Mileage Offset: Formula & Buyback Calculator (2026)

If your car qualifies as a lemon under California’s Song-Beverly Consumer Warranty Act, the manufacturer owes you a buyback. But they don’t refund the full price you paid — they subtract a number called the mileage offset. Depending on when you reported the defect, that number can swing your payout by $5,000 to $15,000 on the same car.

This page breaks down exactly how the mileage offset works under California law, what numbers manufacturers can and can’t use, and how to estimate what your buyback should actually be.

The formula in one sentence

Mileage offset = (miles at first repair attempt ÷ 120,000) × purchase price.

That’s it. The denominator (120,000) is fixed by statute — it’s not a number the manufacturer gets to pick. The numerator is the mileage on your odometer the first time you delivered the car to the dealership for the defect that ultimately makes it a lemon. The “purchase price” is what you actually paid, with specific inclusions and exclusions covered below.

What this means in practice: the earlier you reported the defect, the smaller the offset, and the more of your purchase price you keep.

Why 120,000? The statutory presumption

California Civil Code §1793.2(d)(2)(C) sets 120,000 as the denominator. The reasoning baked into the statute: the legislature presumed a reasonable expected useful life for a new vehicle is 120,000 miles. Courts haven’t budged on this — it’s not a judgment call by the manufacturer or the dealer. It’s a fixed statutory number across the board, regardless of vehicle type.

Don’t let a manufacturer’s representative argue otherwise. If they tell you “we use 100,000 because it’s a luxury vehicle” or “we use 80,000 because EVs degrade faster,” that’s not California law. It’s 120,000 — full stop.

Three real examples on a $50,000 vehicle

Say you bought a vehicle for $50,000 (vehicle price + tax + license fees, excluding extended warranty and GAP). You start having problems and bring the car in to the dealership for the defect that becomes the basis of your lemon claim.

Scenario 1 — First repair attempt at 5,000 miles

• Offset: (5,000 / 120,000) × $50,000 = $2,083
• Your buyback: $50,000 − $2,083 = $47,917
• That’s a 4.2% deduction.

Scenario 2 — First repair attempt at 15,000 miles

• Offset: (15,000 / 120,000) × $50,000 = $6,250
• Your buyback: $50,000 − $6,250 = $43,750
• That’s a 12.5% deduction.

Scenario 3 — First repair attempt at 30,000 miles

• Offset: (30,000 / 120,000) × $50,000 = $12,500
• Your buyback: $50,000 − $12,500 = $37,500
• That’s a 25% deduction.

Same defect, same vehicle, same purchase price. The only thing that changed is when you formally reported the defect. The difference between scenarios 1 and 3 is $10,000 out of the same buyback.

What counts as “purchase price”

Under §1793.2(d)(2)(C), the “actual price” the manufacturer must use in the offset formula is what the buyer paid. Specifically, it includes:

• The vehicle’s sale price
• Manufacturer-installed options (factory navigation, factory-installed sunroof, etc.)
• Transportation/delivery charges
• Sales tax actually paid
• License/registration fees actually paid
• Smog certification fees

It excludes:

• Nonmanufacturer items installed by the dealer or by you — aftermarket wheels, dealer-installed protection packages, ceramic coating, paint protection
• Extended warranties — these are separate consumer products
• GAP insurance — also separate
• Service contracts — separate
• Documentation/dealer prep fees — excluded under California consumer protection rules

This matters because manufacturers often try to lowball the “purchase price” they use in the offset calculation. If you paid $52,000 out the door for the vehicle (including options + tax + license), the offset formula uses that — not $48,000 (the bare vehicle price they may quote you).

Pull out your purchase paperwork. Add up everything you paid that wasn’t an extended warranty, GAP, or non-manufacturer accessory. That’s your “purchase price” for the offset calculation.

What counts as “miles at first repair attempt”

This is where manufacturers and consumers disagree most. The numerator of the offset formula — the mileage when you first delivered the car for repair — directly controls the offset amount. The manufacturer wants this number high; you want it low.

The legal definition: the mileage on the day you first delivered the vehicle to the manufacturer or its authorized dealer for correction of the problem that ultimately constitutes the lemon claim.

A few important clarifications:

It’s not the date you first noticed the problem. Maybe you started hearing a strange noise at 3,000 miles but didn’t bring it in until 7,000. The offset starts at 7,000 — the dealership-delivery date.

It’s not the date the dealer “diagnosed” it. If you brought the car in at 5,000 miles complaining of the issue, but the dealer said “we couldn’t replicate it” and sent you home, that 5,000-mile visit still counts. You delivered the vehicle for correction; that’s the trigger date.

It IS per defect. If you have multiple non-conformities (separate defects), each one has its own first-repair-attempt date and its own offset calculation. A car with a transmission issue first reported at 10,000 miles AND an electrical issue first reported at 25,000 miles can have different offset numbers depending on which defect drives the lemon claim.

It IS the date you formally complained at the dealership. Service records, repair orders, and dealer system entries are the proof. Verbal conversations or phone calls without a paper trail are harder to substantiate.

This is where service records become critical. If your dealership “lost” records of an early repair attempt, manufacturers will claim a later mileage. Keep your repair orders. Keep email confirmations. Keep texts.

What dealers and manufacturers don’t tell you

A few things that aren’t in the manufacturer’s playbook to share:

They calculate the offset based on what’s most favorable to them. If your repair history could support a 7,000-mile or 15,000-mile first-attempt date depending on which defect you claim, expect the manufacturer to argue for whichever is higher.

They sometimes use the wrong “purchase price.” Manufacturer offset calculations frequently exclude charges the statute doesn’t allow them to exclude. Always cross-check their math against what you actually paid out the door, line by line.

Negotiation matters. The mileage offset is a statutory formula, but in practice manufacturers and their counsel sometimes accept a smaller offset than the formula would technically generate — particularly if your case is strong on the merits and they want to settle quickly. Whether that happens depends on your representation and the leverage you bring to the negotiation.

Beyond the offset — what else you might recover

The mileage offset is just one part of what Song-Beverly entitles you to. A complete buyback under California Civil Code §1794(b) typically includes:

• The full purchase price paid (vehicle + tax + license + manufacturer options)
• Minus the mileage offset (the formula above)
• Plus finance charges/interest you actually paid
• Plus incidental damages (rental car costs, towing, registration on the replacement vehicle if you got one)

Plus, in cases of a willful violation, the manufacturer may owe a civil penalty up to two times your actual damages under §1794(c). That penalty isn’t reduced by the mileage offset — it’s calculated against your actual damages. For the right case, the civil penalty can substantially exceed the offset.

And separately: California law shifts the manufacturer’s reasonable attorney fees and costs onto the manufacturer when the consumer prevails. You don’t pay your lemon law attorney out of your buyback. The manufacturer pays their fees directly.

When to talk to a Lemon Law attorney

The mileage offset is calculable from your paperwork. But getting your manufacturer to use the right numbers in the calculation, and getting them to release the buyback without dragging it out, is where representation matters most.

If you have a vehicle that’s been in for repair multiple times for the same problem, or has been out of service for a cumulative 30+ days, you may have a Song-Beverly claim. A free case review will tell you whether the math works out — and whether you’re owed more than just the offset-reduced buyback.