BMW G20 Oil Change (B46, B48 & B58)
The best habit for a long-lived G20 — and an easy hour at home. The procedure is the same across the engines, with the modern-BMW quirks to know: a top-mounted cartridge filter, no dipstick (the level is read in iDrive), and a spec that may be a thinner 0W-20 than you expect. Here's how to do it right for your engine.
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BMW's long service intervals favor the dealer, not the engine — changing the oil more often than the car asks is the cheapest insurance there is, especially on a turbocharged G20. The job is simple; just use the right oil and the right amount for your engine, and know the G20 quirks before you start. (Note: the US B46 is the emissions variant of the B48 — same engine, same procedure.)
Oil & Capacity by Engine
Match the oil and quantity to your engine — and confirm against your car.
| Engine | Oil spec | Capacity (approx) |
|---|---|---|
| B46 / B48 (330i) | BMW Longlife full synthetic — 0W-20 (LL-17 FE+) or 5W-30 (LL-01), by year/market | ~5.3 qt / 5.0 L |
| B58 (M340i) | BMW Longlife full synthetic — confirm 0W-20 / 5W-30 spec | ~6.9 qt / 6.5 L |
Newer modular engines often specify a thinner 0W-20 (LL-17 FE+) — don't assume 5W-30. Capacities are approximate; always confirm the correct oil specification and quantity for your VIN. See our BMW oil guide.
Parts & Tools You'll Need
Right oil, right filter, and the cap socket that fits the housing.
Step-by-Step
Warm the Engine Slightly
Run the engine for a few minutes so the oil flows and drains fully — warm, not scalding. Then shut it off, raise the front and support it securely on stands.
Remove the Underbody Panel
Take off the plastic undertray to reach the drain plug. Note which fasteners go where so it goes back cleanly.
Drain the Oil
Position the pan, remove the drain plug and let it drain fully. Inspect the old oil as it goes. Fit a new crush washer and reinstall the plug to spec.
Replace the Cartridge Filter (Top)
The filter is on top of the engine. Unscrew the plastic cap with the cap socket, lift out the old paper element, and fit the new one. Replace the cap's O-rings from the kit, then thread the cap back on and torque it — gently; it's plastic.
Refill With the Correct Amount
Add the right oil for your engine, slightly under the listed capacity to start. Because there's no dipstick, measure what you pour in rather than guessing — then fine-tune by the electronic gauge.
Run, Then Check the Level Electronically
Lower the car, start it and let it idle to circulate, checking for leaks at the plug and filter cap. Shut it off, wait a few minutes on level ground, then read the oil level in the iDrive menu (the G20's electronic replacement for the dipstick) and top up to the middle of the range.
Reset the Service Reminder
Reset the Condition Based Service oil item in the iDrive menu so the countdown restarts. Dispose of the old oil and filter at a recycling point.
Confirm the spec, measure the fill, mind the cap
Don't assume 5W-30 — many modular G20 engines call for a thinner 0W-20 (LL-17 FE+), so confirm the correct spec for your VIN. There's no dipstick, so set and check the level through iDrive and measure what you add. And the filter cap is plastic — torque it to spec, never gorilla-tight, or it can crack. Hot oil burns; let it cool if needed.
Quick Specs
General guidance — verify for your exact engine and year.
| Item | Detail |
|---|---|
| Filter | Top-mounted paper cartridge (replace cap O-rings) |
| Oil | BMW Longlife full synthetic — 0W-20 (LL-17 FE+) or 5W-30 (LL-01); confirm |
| Capacity | B46/B48 ~5.3 qt; B58 ~6.9 qt |
| Level check | Electronic — via the iDrive menu (no dipstick) |
| After | New drain-plug washer; reset CBS in iDrive |
FAQ
How often should I change the oil?
BMW's interval is long; most enthusiasts change every 7,500 miles or once a year, and sooner for hard-driven or tuned cars. Frequent changes are the cheapest protection for these turbocharged engines.
What oil and how much does my engine take?
A BMW Longlife full synthetic — often 0W-20 (LL-17 FE+) on the modular engines, sometimes 5W-30 (LL-01) — roughly 5.3 quarts for the B46/B48 and about 6.9 for the B58. Always confirm the exact specification and capacity for your VIN.
0W-20 or 5W-30 — which does it take?
It depends on the engine and model year. Many newer modular G20s specify a thinner 0W-20 to LL-17 FE+, while some call for 5W-30 to LL-01. Don't assume — check the cap, the manual, or your VIN, and match the spec exactly.
There's really no dipstick?
Correct — the G20 monitors oil level electronically and shows it in the iDrive menu. Check it on level ground with the engine warm but off for a few minutes, and set the level by what you measure in.
Can I reset the service light myself?
Yes. The Condition Based Service oil item resets through the iDrive menu after the change, with no special tool needed — just follow the on-screen reset for the engine-oil service.
You're Done
Fresh oil and filter, the right grade and amount for your engine, level set by the electronic gauge and the service reset — the single best habit for a long-lived G20. Top-mounted cartridge, no dipstick, gentle on the plastic cap, the right Longlife spec (often 0W-20), and changed on the early side. For the right oil see our oil guide, and head back to the G20 hub for the rest.