Most new US vehicles carry a 3-year/36,000-mile bumper-to-bumper (basic) warranty and a 5-year/60,000-mile powertrain warranty as the industry baseline. Hyundai, Kia and Genesis lead the market with a 10-year/100,000-mile powertrain warranty, though that longer term applies only to the original owner — it drops to 5 years/60,000 miles if the car is resold. Federal emissions rules require EV and plug-in hybrid battery coverage of at least 8 years/100,000 miles. Using an independent mechanic or aftermarket parts does not automatically void your warranty under the federal Magnuson-Moss Warranty Act — the dealer must prove that specific part or service caused the failure.
At a glance: typical manufacturer coverage
| Coverage type | Typical duration |
|---|---|
| Basic/bumper-to-bumper | 3 years / 36,000 miles |
| Powertrain (industry standard) | 5 years / 60,000 miles |
| Powertrain (Hyundai/Kia/Genesis/Mitsubishi, original owner) | 10 years / 100,000 miles |
| Corrosion/rust-through | 5-12 years, unlimited miles (varies by brand) |
| EV/PHEV battery (federal minimum) | 8 years / 100,000 miles |
| Roadside assistance | Usually matches basic warranty term |
How the coverage layers work
A new-car warranty isn't one blanket policy — it's several overlapping terms that expire at different times. The basic (bumper-to-bumper) warranty covers nearly everything for the shortest period, typically 3 years or 36,000 miles, whichever comes first. The powertrain warranty covers the engine, transmission and drive components for longer — typically 5 years/60,000 miles — since those are the most expensive parts to replace. A separate corrosion warranty (5-12 years, often unlimited mileage) covers rust perforation of body panels, and roadside assistance usually rides alongside the basic warranty term.
What's covered under each layer
| Layer | Typically covers | Typically excludes |
|---|---|---|
| Bumper-to-bumper | Electronics, A/C, audio, most mechanical parts | Tires, brakes, wiper blades, bulbs, routine maintenance |
| Powertrain | Engine block/internals, transmission, drive axle, transfer case | Clutch wear, routine fluid changes |
| Corrosion | Sheet-metal rust-through from the inside out | Surface rust, stone chips, cosmetic damage |
| EV/PHEV battery | Battery capacity loss below a stated threshold, defects | Capacity loss from normal aging within spec, physical damage |
How automakers compare
Hyundai, Kia and Genesis (all part of Hyundai Motor Group) and Mitsubishi lead US warranty coverage with a 10-year/100,000-mile powertrain warranty — but read the fine print: that extended term is non-transferable and applies only to the original registered owner. If the car is sold, remaining coverage drops to the industry-standard 5 years/60,000 miles for the next owner. Toyota, Honda and most mainstream brands hold to the 3-year/36,000-mile basic and 5-year/60,000-mile powertrain baseline, while luxury brands (BMW, Mercedes-Benz, Audi) often extend the basic warranty to 4 years/50,000 miles but keep the powertrain term shorter than Hyundai/Kia's.
EV and hybrid battery warranties
Because of federal Clean Air Act emissions-warranty requirements, every plug-in vehicle sold in the US must carry at least an 8-year/100,000-mile battery warranty (California's rules, which several other states follow, extend some emissions-related components further). This covers manufacturing defects and capacity loss below a stated threshold — commonly 70% of original capacity — but not the gradual, expected capacity fade every lithium-ion battery experiences with age and charge cycles.
What actually voids a warranty (and what doesn't)
The federal Magnuson-Moss Warranty Act prohibits a manufacturer from voiding your warranty simply because you used an independent mechanic or installed an aftermarket part. To deny a claim, the manufacturer or dealer must show that specific part or service actually caused the failure being claimed — a blanket "you didn't service here, so it's void" denial is illegal. That said, some actions genuinely do void coverage:
- Odometer tampering or rollback.
- Off-road, racing or commercial use of a vehicle warranted for personal use only.
- Modifications that directly cause the failure (e.g., an aftermarket tune that damages the engine).
- Neglecting manufacturer-scheduled maintenance to the point it causes the failure — keep receipts even from independent shops.
- Salvage-title rebuilds in most cases, since the factory warranty typically doesn't survive a total-loss designation.
Certified Pre-Owned (CPO) extends the clock
Buying a manufacturer-backed Certified Pre-Owned vehicle typically restarts or extends the powertrain warranty (commonly to 6-7 years/100,000-125,000 miles from the original in-service date) and adds a shorter bumper-to-bumper term, on top of a multi-point inspection. CPO premiums usually run $1,000-$3,000 over a comparable non-certified used car — worth comparing against buying independently and adding a third-party service contract instead.
Mistakes to avoid
- Assuming a longer advertised powertrain warranty transfers in full to a used buyer — check the transfer terms.
- Skipping scheduled maintenance and losing receipts, which weakens your position if a claim is disputed.
- Confusing the emissions-mandated EV battery warranty length with the total ownership cost of eventual battery degradation.
- Believing aftermarket parts automatically void coverage — know your Magnuson-Moss rights before accepting a denial.
Frequently asked questions
Does using an independent mechanic void my new car warranty?
Which automaker has the longest warranty in the US?
How long is the warranty on an EV battery?
Does a manufacturer warranty transfer if I sell the car?
What's the difference between a manufacturer warranty and an extended warranty?
Sources & further reading
- FTC — Businessperson's Guide to Federal Warranty Law (Magnuson-Moss)
- U.S. EPA — Vehicle Emissions Warranty and EV Battery Requirements
- Hyundai USA — America's Best Warranty Program
Figures, prices and policy details were current at the last-updated date above. Automotive pricing, incentives and regulations change frequently — verify time-sensitive details with the linked primary sources. Read our editorial policy and fact-checking standards.
