The short version: on a used car the biggest difference between these two isn't range or performance — it's how much manufacturer cover is left, and that gap is wider than most buyers realise. Everything below is sourced from the manufacturers' own Australian warranty terms, listed at the bottom with the date we checked them.
Warranty: the real difference
Both brands cover the high-voltage battery for eight years with a 70% capacity floor. The vehicle warranty is where they diverge, and on a three-year-old car that difference is worth real money.
| Tesla Model 3 | BYD Seal | |
|---|---|---|
| Vehicle warranty | 5 years, unlimited km — but only for vehicles delivered from 1 Jan 2026. Earlier cars: 4 years / 80,000 km | 6 years / 150,000 km |
| HV battery warranty | 8 years / 160,000 km (RWD); 8 years / 192,000 km (Long Range, Performance) | 8 years / 160,000 km |
| Capacity floor | Minimum 70% retention | Minimum 70% retention |
| Commercial use | Vehicle warranty capped at 5 years / 150,000 km | Check the specific VIN — terms and exclusions apply |
| Scheduled servicing | No fixed interval — condition-based | 12 months / 20,000 km |
Read the first row again, because it's the one that catches people out. A 2023 Model 3 was delivered under the old four-year, 80,000 km vehicle warranty — on a car that's done average kilometres, that cover is either gone or nearly gone. A 2023 Seal still has years of its six-year vehicle warranty to run. The battery is protected either way; the window motors, screens and trim are not.
The flip side: BYD's cover comes with a fixed service schedule. Miss the stamps and you hand the manufacturer an argument. Tesla has no equivalent hook, so a patchy history costs you less. More on how cover works on the battery warranty page.
Chemistry: same problem, different reason
The Seal uses lithium iron phosphate Blade packs across the range. Tesla uses LFP in standard-range and rear-drive Model 3 builds, and nickel-based chemistry in Long Range and Performance cars. So on an entry-level example of either, you're looking at LFP — and LFP has a famously flat voltage curve that makes app-based state of health estimates close to meaningless.
That cuts both ways. LFP tolerates daily charging to 100%, handles Queensland heat better and generally ages slowly, so the odds are good. But "the odds are good" is not a number, and it's not what you're paying tens of thousands of dollars on. Both cars need a diagnostic read — see how state of health is tested.
On a Long Range or Performance Model 3 the chemistry is different again, and the ordinary degradation curve applies — what's normal for its age becomes the relevant question.
History: what each car is likely to have done
Model 3 — the volume problem
On sale here since 2019, so the used pool is deep and varied. That's an advantage — you can walk away from any single car. It also means a much higher share of ex-rideshare and ex-hire examples with very high cycle counts and near-exclusive DC fast charging, rarely disclosed in the ad.
Seal — the young-car problem
Only on sale here since late 2023, so almost every used example is a first-owner car with a short history. Less to go wrong, but also less to verify against — and BYD's service network was stretched early, so "no service history" is common and matters more here than on the Tesla.
What we check differently on each
On the Model 3 — charge history and suspension
Cycle counts and the DC-to-AC mix, because that's what separates a home-charged private car from a former rideshare vehicle with the same odometer. Then the front upper control arms and a paint-depth survey for undisclosed repair.
On the Seal — 12-volt system and software state
The 12-volt battery tested under load, not at rest, because a weak one produces symptoms that look catastrophic. Then the firmware version and whether any outstanding service action sits against the VIN.
On both — a live charge session
Intermittent AC charging faults don't appear in a stationary scan on either car. We plug in and watch it work, and record what was and wasn't tested.
On both — usable capacity and cell spread
Read from the battery management system and reported with the VIN on it, so the number means something to a seller, a dealer, or a warranty claim later.
So which one?
We inspect both and we sell neither, so the honest answer is that the individual car decides it. A well-kept, home-charged Model 3 with a healthy pack is a better buy than a neglected Seal, and vice versa. What we'd say is this: if two cars are close on price and condition, remaining vehicle warranty is the tiebreaker most buyers underweight — and right now that generally favours the Seal.
Model-specific detail is on the Model 3 page and the Seal page.
Sources and how we checked
Warranty terms above were taken from the manufacturers' published Australian terms and contemporaneous Australian motoring press coverage, checked on 2 August 2026. We've deliberately left prices and range figures out — they change constantly, and a stale number is worse than none.
- Tesla Australia vehicle warranty change to five years / unlimited kilometres for vehicles delivered from 1 January 2026, replacing four years / 80,000 km; battery and drive unit cover unchanged at 8 years / 160,000 km (RWD) and 8 years / 192,000 km (Long Range, Performance) with 70% minimum retention.
- BYD Australia published warranty: vehicle 6 years / 150,000 km; traction battery 8 years / 160,000 km, whichever occurs first, terms and conditions applying. Servicing at 12 months / 20,000 km.
- BYD Seal Australian launch: late 2023. Tesla Model 3 Australian availability: from 2019.
Terms change, and they can differ by variant, build date and how a specific car has been used. Always confirm the position for the exact VIN with the manufacturer in writing before you pay — we do it as part of every inspection and put it in the report.
Comparing two actual cars? We'll settle it.
Measured battery health and a written verdict on each, anywhere in Brisbane, Sydney and Melbourne.