BMW
BMW 3 Series
The reference compact sport sedan, and a car whose running costs punish deferred maintenance harder than most.
The G20 3 Series is the best-executed version of the formula in years: the chassis is composed without being harsh, the B48 four-cylinder is more responsive than its output suggests, and the interior finally matches the price. As a driving instrument it is the reference point for the segment.
The ownership math is where buyers get caught. BMW's Condition Based Service system spaces oil changes further apart than most owners are comfortable with, and cooling system components — the electric water pump, thermostat and plastic expansion tank — are wear items rather than lifetime parts. Budget for them rather than treating them as failures. Valve cover and oil filter housing gaskets leak on most examples past 80,000 miles.
The realistic plan is to find an independent BMW specialist before you need one, use original-supplier parts rather than dealer-boxed equivalents, and set aside $1,200 to $2,500 a year once out of warranty. Done that way, a 3 Series is affordable to keep. Done reactively at dealer rates, it is not.
Generations
What changed, and which years share the same hardware.
F30
2012–2018
Introduced turbocharging across the range: the N20 2.0L four in the 328i and the N55 3.0L single-turbo six in the 335i, later replaced by the B48 and B58. Early N20 engines are known for timing chain guide wear; the B48 and B58 that followed corrected it.
G20
2019–2025
Built on the CLAR platform with a stiffer body, a much better interior and lift-related dampers as standard. The B48 2.0L turbo four powers the 330i and the B58 3.0L turbo six the M340i. A 2023 facelift brought the curved display and iDrive 8.
G50
2026–present
New generation adopting BMW's Neue Klasse-derived interior architecture and electrical platform, with heavily revised electrified powertrains.
Model years
Reliability, reported issues and annual running costs, year by year.