The 2022 and 2023 G01 X3 manuals show engine coolant reservoir item 3 and an optional radiator reservoir item 4. The new 2025 G45 manual reverses those labels: item 4 is engine coolant, and optional item 3 is the additional radiator. The 2023 and 2025 manuals explicitly recommend BMW LC-18, while the 2022 booklet does not name LC-18 in its checked section.
Do not infer that all 2022 X3 vehicles require a different coolant or that LC-18 can be retrofitted without approval. The 2025 G45 is a new vehicle generation; its diagram numbers, fluid checks and parts must not be copied onto a G01. Confirm the current BMW guidance for the individual VIN before buying or mixing coolant.
Hot pressure caps can release scalding coolant. Stop safely for steam, overheating or rapid fluid loss. Individual engines can have one or two cooling reservoirs; confirm BMW VIN-specific equipment before accessing either circuit.
Generation difference: G01 2022–2023 = engine reservoir item 3 / optional additional radiator item 4. G45 2025 = engine reservoir item 4 / optional additional radiator item 3. Never follow the older diagram numbers on the new X3.
| Verified field | 2022 US X3 G01 | 2023 US X3 G01 | 2025 US X3 G45 |
|---|---|---|---|
| Generation | G01 | G01 | G45 |
| Original BMW manual edition | 01405A38514 · VI/21 | 01405A602E0 · VI/22 | 01405B45FC2 · VI/24 |
| Coolant additive | Specifies suitable coolant additive with 50:50 water/additive mixing, without explicitly naming BMW LC-18 in this manual's coolant section. | Explicitly recommends BMW LC-18; also specifies 50:50 water/additive mixing and says not to mix different-color additives. | Explicit BMW LC-18 recommendation; 50:50 water/additive. Do not infer parts interchangeability from G01. |
| Reservoir identification | Engine reservoir = component 3; optional additional-radiator reservoir = component 4, depending on engine. | Engine reservoir = component 3; optional additional-radiator reservoir = component 4, depending on engine. | Engine reservoir = item 4; optional additional-radiator reservoir = item 3. This is REVERSED versus the 2022/2023 G01 diagrams. Washer fluid = item 7. |
| Level-check condition | Completely cool engine; read MIN/MAX inside filler neck and follow the exact vehicle manual. | Completely cool engine; read MIN/MAX inside filler neck and follow the exact vehicle manual. | Engine fully cooled; switch climate control OFF; correct level is just below max mark inside filler neck. G45 procedure is not G01 MIN/MAX wording. |
| Engine-bay diagram page | Printed p. 359 | Printed p. 360 | Printed p. 362 |
| Coolant instructions | Printed pp. 366–367 | Printed pp. 367–368 | Printed pp. 369–370 |
Specifies suitable coolant additive with 50:50 water/additive mixing, without explicitly naming BMW LC-18 in this manual's coolant section.
Read the original BMW-authored manual (third-party archived PDF) ↗
Explicitly recommends BMW LC-18; also specifies 50:50 water/additive mixing and says not to mix different-color additives.
Read the original BMW-authored manual (third-party archived PDF) ↗
Explicit BMW LC-18 recommendation; 50:50 water/additive. Do not infer parts interchangeability from G01.
Read the original BMW-authored manual (third-party archived PDF) ↗
The 2022–2023 G01 and 2025 G45 manuals cover different generations and multiple engine installations. An individual X3 may have one or two coolant reservoirs. The new 2025 G45 coolant-level description is just below the max mark inside the filler neck with climate control off, while the older G01 wording refers to internal MIN/MAX marks. No year is evidence that a particular reservoir or cap is defective, and no universal part number or repair cost is established here.
The manufacturer-authored PDFs are mirrored by a third-party archive, not hosted by BMW. Confirm the latest equipment-specific guidance through BMW USA's owner-manual lookup ↗ or the integrated Owner's Manual in the vehicle.
