⚡ The quick answer
Here is the trap people fall into: they walk into a parts store, grab any 5W-30, and pour it in. BMW engines are built around the brand's own Longlife (LL) oil standards, which control things like high-temperature shear stability and timing-chain wear that a generic API rating does not guarantee. If you run an oil that does not carry the right BMW approval, you can accelerate wear on the very parts these engines are already known to chew through, like the N20 timing chain or the VANOS solenoids. Use the right grade and the right approval and a 3 Series engine will happily run past 150,000 miles.
📋 Oil spec by engine
The 3 Series spans a lot of engines across the E90, F30 and G20 generations. Find your engine code (it is on the build sticker or in the manual) and match the row below. Weights and capacities are the manufacturer figures; always verify on the oil cap or owner's manual for your exact build.
| Engine | Years | Oil Type / Weight | BMW Approval | Capacity |
|---|---|---|---|---|
| N52 (328i I6) | 2006-2013 | Full synth 5W-30 | LL-01 | ~6.9 qt |
| N54 (335i twin-turbo I6) | 2007-2013 | Full synth 5W-30 | LL-01 | ~6.9 qt |
| N55 (335i single-turbo I6) | 2011-2015 | Full synth 5W-30 | LL-01 | ~6.5 qt |
| N20 / N26 (328i turbo 4) | 2012-2016 | Full synth 5W-30 | LL-01 | ~5.3 qt |
| B46 / B48 (330i turbo 4) | 2016-present | Full synth 0W-20 | LL-17 FE+ | ~5.2 qt |
| B58 (340i / M340i I6) | 2016-present | Full synth 0W-20 | LL-17 FE+ | ~6.9 qt |
| N47 / B47 (318d/320d diesel) | 2007-present | Full synth 5W-30 | LL-04 | ~5.3-5.8 qt |
| S55 (M3 F80) | 2014-2018 | Full synth 10W-60 | BMW M TwinPower / LL-01 | ~6.6 qt |
Two things to read from this table. First, the weight is not one-size-fits-all: older engines want 5W-30, the newest gas engines want 0W-20, and the high-revving M cars historically used a heavy 10W-60. Second, diesels carry the LL-04 approval (low-SAPS for the particulate filter), which is not interchangeable with the LL-01 used on gas engines even at the same 5W-30 weight.
🔧 Type, weight, and capacity explained
Type: always full synthetic
Every modern 3 Series engine requires full-synthetic oil. These are turbocharged or high-output engines that run the oil hot, and conventional or synthetic-blend oil will break down faster and coke up turbo bearings and timing components. There is no 3 Series that should ever see conventional oil.
Weight: 5W-30 vs 0W-20
The 5W-30 grade dominates the E90 and early F30 years. Around the 2015-2016 switch to the modular B-series engines, BMW moved to 0W-20 with the LL-17 FE+ standard to squeeze out fuel-economy gains. If you have a 330i, 340i or M340i from 2017 on, you almost certainly want 0W-20. If you have a 328i, 335i or anything with an N-code engine, you want 5W-30.
Capacity: 5 to 7 quarts
Four-cylinder turbos (N20, B46/B48) hold roughly 5.0 to 5.3 quarts. The inline-sixes (N52, N54, N55, B58) hold closer to 6.5 to 6.9 quarts. Never fill to a fixed number from memory. Many later 3 Series have no traditional dipstick and instead use an electronic oil-level gauge in iDrive, so fill in stages and re-check. Overfilling a BMW can foul the crankcase ventilation and cause smoking.
⚠️ Common mistakes to avoid
- Buying on weight alone. A 5W-30 without the LL-01 stamp is not BMW-approved. Look for "BMW Longlife-01," "LL-04," or "LL-17 FE+" on the back label.
- Mixing diesel and gas oil. LL-04 diesel oil and LL-01 gas oil are not swappable. Putting full-SAPS gas oil in a diesel can clog the particulate filter.
- Putting 0W-20 in an N54 or N55. Those turbo sixes were engineered around 5W-30. The thinner oil can drop oil-film thickness under boost and heat.
- Stretching the interval to 15,000 miles. BMW's Condition Based Service allows it, but turbo engines like the N20 and N54 live longer on a 5,000 to 7,500 mile change. If you are chasing a P0011 timing-correlation code or rough idle, fresh oil and a clean filter are the cheapest first move.
- Ignoring oil consumption. Some N20 and N52 engines burn a quart every 1,000 to 2,000 miles. Track it. If you are losing more than that or seeing blue smoke from the exhaust, that is a valve-seal or PCV issue, not just an oil-grade question.
🧮 How to confirm the right oil for your car
Follow this order and you will not guess wrong:
- Read the oil cap. Many 3 Series stamp the required grade right on the filler cap (for example "0W-20" or "5W-30").
- Check the owner's manual. It lists the BMW LL approval and capacity for your exact build, including market-specific differences.
- Match the LL approval on the bottle. Grade and approval both have to match. A 5W-30 LL-01 and a 5W-30 LL-04 are not the same product.
- Confirm capacity, then fill in stages. Add about 80 percent of the listed capacity, run the engine, let it settle, then top up to the dipstick or iDrive gauge.
If your oil-pressure light is on or you are smelling burnt oil, do not just change the oil and hope. Run a quick AI diagnosis first, or if a shop already quoted you a repair, sanity-check the price with our quote checker before you pay.
❓ Frequently asked questions
📝 TL;DR
- Type: full synthetic, always, on every 3 Series engine.
- Weight: 5W-30 for N-series engines (328i, 335i, diesels); 0W-20 for newer B-series (330i, 340i, M340i).
- Approval: LL-01 (gas), LL-04 (diesel), or LL-17 FE+ (newest gas). Match it on the bottle.
- Capacity: about 5.0-5.3 qt on four-cylinders, 6.5-6.9 qt on inline-sixes.
- Interval: 5,000-7,500 miles is the safe real-world number, even if CBS says further.