A convertible is usually a second thought for a Singapore buyer, chosen with the heart. The bills, though, follow the same rules as any other car. This page sets out what the BMW 4 Series Convertible costs to keep: the list price, the COE, road tax and car insurance, each with its date.
The insurance prices are examples, read on 20 October 2026, for one stated driver and car. Your own premium depends on your answers. Read them as a guide to the costs, not as an offer.
Versions
The new-car list read on 2026-10-10 has one version: the 420i M Sport Pro, a petrol car made in Germany, listed under the sports body type, with 181bhp from 1,998cc.
The quote form has three versions, all with a 1,998cc engine:
- 420i M Sport
- 420i M Sport Pro
- 430i M Sport Pro
The figures below are for the 420i M Sport, the version most insurers quote. As all three share an engine size, they share the same road tax.
List price
As listed on 2026-10-10, with COE included in the list price that day, the 420i M Sport Pro was S$379,888.
That figure moves with the COE each round, so a list price from one date is a snapshot. Ask what each offer includes, such as the COE, registration and any service package, before you compare. The 420i M Sport and 430i M Sport Pro on the quote form are not on the list that day, so any you find will most likely be used cars.
COE
The price page states that the 420i M Sport, with a 1,998cc engine above 1,600cc, needs a Category B COE. Category B closed at S$130,100 in the October 2026 1st round. The COE page has later results.
On a used car, the COE has already been paid. What you buy is the time left on it, so ask for the expiry date and weigh it against the asking price.
Road tax
For the 1,998cc engine, LTA's formula gives S$1,209.76 a year, before any age surcharge.
If the car is kept past 10 years on a renewed COE, a surcharge is added:
- Over 10 years: +10%
- Over 11 years: +20%
- Over 12 years: +30%
- Over 13 years: +40%
- Over 14 years: +50%
The road tax page explains the formula.
Car insurance: the numbers
The BMW 4 Series Convertible price page prices this example:
- Car: 420i M Sport, registered 3 years ago, private use, comprehensive cover
- Driver: aged 40, married, office job, driving 10 to 19 years
- Record: 50% no-claim discount (NCD), no claims
- Repairs: authorised workshop, no options
9 insurers price the car for that driver. The lowest premium is S$1,027.39 a year. The insurer whose lowest plan is the dearest asks at least S$3,994.05. That is S$2,966.66 more, or 289% on top. All prices include 9% GST.
With fewer insurers than for an everyday sedan, and a gap of that size, the choice of insurer matters a great deal. A few prices on the page are estimates, so the insurer's own quote has the final figure.
Excess
The excess is your share of each claim. Most plans for this car carry S$600. Others sit at S$500, S$750 or S$800, one asks S$2,500, and one has no excess. Read each premium together with its excess.
How the premium reacts
The price page gives the lowest premium after one change:
- No NCD (0%): S$1,517.28, S$489.89 more
- 20% NCD: S$1,517.28, S$489.89 more
- Driver aged 27, 3 years' driving, 30% NCD: S$1,438.34, S$410.95 more
- Driver aged 65, 20 or more years' driving: S$1,027.39, the same
- A new car, registered this year: S$1,027.39, the same
- A car 8 years old: S$1,027.39, the same
Only the driver's record moves the lowest price. With no NCD it is 48% higher, and a younger driver with a short record pays S$410.95 more. The older driver, the new car and the 8-year-old car all land on the same lowest premium.
That steadiness applies to the lowest plan only. Other plans on the page may still change with the car's age, so check the full list for your case.
Similar cars
For the same driver and car age, the price page compares six cars:
- Lexus NX: S$972.39
- Lexus RX: S$972.39
- Mercedes-Benz GLC: S$925.60
- Mercedes-Benz E-Class: S$861.03
- Toyota Voxy: S$793.75
- Toyota Harrier: S$742.90
They average S$878.01. The 4 Series Convertible costs 17% more than that, and all six are cheaper to insure. The BMW car insurance page covers the make's other models, and the cheapest cars to insure page ranks more.
Costs that turn on your own use
- Parking: season parking at home, plus work and town parking. A covered lot may matter more for a soft-top car.
- Petrol: depends on your distance and the pump price.
- ERP: depends on your routes and the hours you drive.
- Servicing and repairs: follow the maker's schedule. Ask what the warranty covers, including the roof.
- Depreciation: shaped by what you pay and what the car fetches later.
Summary of yearly costs we can show
For the 420i M Sport, dated:
- Road tax: S$1,209.76 a year, before any age surcharge (LTA's formula, checked 2026-10-19)
- Insurance, standard driver: from S$1,027.39 a year (20 October 2026)
- Insurance, no NCD: from S$1,517.28
- Insurance, car 8 years old: from S$1,027.39
The one-off costs, for reference: a list price of S$379,888 for the 420i M Sport Pro as listed on 2026-10-10, and a Category B COE of S$130,100 in the October 2026 1st round.
Before you buy: car insurance for the BMW 4 Series Convertible
Before you drive off, get your car insurance through Shenton Brokers. Compare car insurance for the BMW 4 Series Convertible to see today's prices from every insurer we compare and how they change with the driver and the car's age. Or get a quote with your own details.