BYD Dolphin vs BYD Seal 6Electric or plug-in hybrid: which costs less?

Before on-road costs (+ on-roads): the car's list price only. You pay extra government charges and dealer fees on top when you buy.

On-road costs: stamp duty, first year's registration, compulsory third party (CTP) insurance, number plates and the dealer's delivery fee. They usually add $3,000–6,000 depending on the car and your state. Where a price is "before on-roads" we add about $4,000. See stamp duty and rego by state.

Drive-away: a price that already includes the on-road costs, so it's what you actually pay to drive the car home.

On the road price: the drive-away price, or the list price plus our on-road estimate.

Cost to own: everything you'd spend over the years you keep the car (5 unless you change it): the on the road price, plus a home wall charger for EVs (about $2,000, one-off), plus charging or fuel, scheduled servicing and tyres for every year. Divide it by the number of weeks to see what the car really costs you each week.

Match score (Pick my car): this is about fit, not quality. Each car that fits your answers is compared only with the other cars that fit, on eight things, and a car that does something less well than the others in that group scores lower on it, even if it's good at it. Change your budget or answers and the group changes, so the scores do too. The eight things: how much car the money buys (price, 20%), ANCAP safety rating (15%: a current rating counts in full, an expired one less, and a car ANCAP hasn't rated counts as middling), range (15%), performance (0–100 km/h, or power where no time is published, 10%), fast-charging speed (peak DC kW, 10%), warranty length (10%, with the battery warranty counted for cars that plug in), servicing and tyre costs (15%), and recalls and track record (5%: major recalls in Australia on our list count against a car (our recall list covers the bigger, well-reported ones, so a clean record here is not a guarantee), and models sold here for longer get a little credit). A figure we don't have counts as middling, not as bad. "Most car for my budget" ranks by this match score; "Lowest cost to own" ranks by cost and uses the score only to split near-ties.

Not included: yearly rego renewals and insurance after the first year (see what EVs and hybrids cost to insure), finance interest, and what the car is worth when you sell it. These vary too much by person and car to estimate fairly, and resale value is the biggest unknown, especially for newer brands.