F33 · 428i Convertible

What the F33 Chassis Is

The BMW F33 is the convertible variant of the first-generation 4 Series, spun off from the 3 Series line when BMW rebranded its two-door coupes and convertibles as a distinct model family. Produced from 2014 to 2020, the F33 uses a three-piece retractable hardtop that folds electrically into the trunk, giving it coupe-like refinement when closed and full open-air motoring at the touch of a button. Compared to the outgoing E93 convertible, the F33 gained a wider track, a lower stance, and sharper handling that made it one of the most complete drop-tops in its class.

Models & Body Styles

The F33 was offered in the U.S. exclusively as a two-door convertible, spanning a broad lineup of rear- and all-wheel-drive versions:

• 428i Convertible (including SULEV and xDrive variants)
• 430i Convertible (including SULEV and xDrive variants)
• 435i Convertible and 435i xDrive Convertible
• 440i Convertible and 440i xDrive Convertible

A 2016 mid-cycle refresh brought the shift from 428i to 430i and from 435i to 440i, marking new engine designations and detail updates. You can confirm the exact build of any car using our VIN decoder.

Engines & Drivetrains

Four-cylinder models (428i/430i) run BMW's turbocharged 2.0-liter N20, later replaced by the more refined B48 in the 430i. The six-cylinder cars are the enthusiast picks: the 435i uses the celebrated turbo 3.0-liter N55, while the post-refresh 440i moves to the smoother, torque-rich B58. Most cars pair with the ZF eight-speed automatic, though a six-speed manual was available on select six-cylinder models. Optional xDrive all-wheel drive adds year-round confidence. To understand how these powertrains fit into BMW's broader engineering story, see our BMW DNA overview.

Owning & Buying an F33

The F33 is a genuinely usable convertible—refined at highway speeds with the top up, and quick to open. Buyers should budget for the folding-roof mechanism and check for proper operation, along with the usual F-generation items like the electric water pump, oil filter housing gasket seepage on the N20/N55, and cooling system maintenance. Cars with the six-cylinder engines command a premium and reward it with the strongest character.

Enthusiasts cross-shopping earlier open-top BMWs often compare the F33 against the E64 6 Series Convertible and the sporty E63 coupe, though the F33 is a more compact, modern package.

Strengths & Weak Points

• Strengths: hardtop refinement, strong turbo engines, xDrive availability, everyday livability.
• Watch for: roof mechanism wear, added weight over the coupe, and standard cooling and gasket maintenance.