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G20 Common Problems by Engine
How reliable the current 3 Series really is — the modular B48 four, the standout B58 six, the diesels and the 330e hybrid, plus the issues they share and which to buy.
Read the guide →330i vs M340i: Which to Buy?
The B48 four against the B58 six, head to head — power, drivetrain, suspension, cost and character, with a clear which-to-buy verdict.
Read comparison →330e Plug-in Hybrid
How the plug-in hybrid works — the B48-plus-electric drivetrain, the battery and charging, the trade-offs, and what to check.
Read guide →Buying
DIY Guides
Oil Change by Engine
The routine service done right — the correct Longlife oil (often 0W-20) and capacity for the B46/B48 or B58, the top cartridge filter and the electronic level.
Read guide →Front & Rear Brake Pads
All four corners — the easy fronts and the rears done right, with the electronic parking brake in service mode.
Read guide →Cabin Air Filter (5 Minutes)
The easiest win on the car — swap the cabin microfilter under the hood, no tools, in about five minutes.
Read guide →Battery Replacement & Registration
The trunk-mounted swap and the all-important registration step.
Read guide →Ownership
Parts & Accessories
Best G20 Accessories
The accessories that earn their place — all-weather mats, a cargo liner, a dash cam, a portable inflator for the run-flats, and more.
Read guide →Best Floor Mats
All-weather liners, OE-look carpet and cargo liners cut for the G20 sedan and Touring — with what to check for fitment.
Read guide →Best Oil (B48 / B58)
The right Longlife spec for your engine — 0W-20 or 5W-30 — capacities, and when to step up for a tuned turbo.
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