The SMG transmission system does not and will not drive like an automatic. You are most likely just not used to the way it works, unless you have time in someone elses SMG and are making a direct comparison. Be more specific with what you are feeling that makes you think there is a problem, RPMs, shift level selected etc.
SMG parts and repairs are VERY expensive. One service I CAN provide for SMG owners is flash programming Euro SMG transmission software into your transmission control module. This upgrade transforms the SMG. Significantly improved shift quality and the ability to do launch control at 4k rpm with automatic upshifting at the redline. What is a BMW SMG Transmission? SMG stands for Sequential Manual Gearbox. It's essentially a transmission capable of functioning as an automatic, or functioning as a manual transmission. The innovation is that, when functioning as an automatic, the driver does not need to operate a clutch pedal, simply designate desired gear. BMW's final AMT (before being replaced by a dual-clutch transmission) was the 7-speed SMG-III used in the 2004-2010 BMW E60 M5and related BMW E63 M6. The SMG-III could achieve a shift time of 65 milliseconds in its most aggressive mode.
BMW Transmission & Differential Oil
This page covers fluid information and recommendations for BMW manual and automatic transmissions, rear differentials, and front differentials on xDrive models. Note: for the purposes of this page, 'Vintage' refers to all BMW cars built up to and including the E30 3-series.Jump to:
Bmw Smg Transmission Fluid
Fluid for manual transmissionFluid for automatic transmission
Fluid for front axle or transfer case
Fluid for rear differential
BMW Manual / SMG / DCT Transmission Fluid
Vintage 5-speed manual
Most manual transmissions on vintage models do not have a fluid label on the transmission because nearly all gearboxes took the same fluid - a universal GL-4. If no label is present, the official recommendation is any GL-4 gear oil. Our favorite is the Red Line MTL. However, some transmissions will have an orange ATF label and you should use a Dexron III ATF fluid. The 1984-1986 325e/528e should have a green 'Special Oil' label on the transmission. These transmissions use a specific Mobil SHC 630 synthetic fluid (SAE 90 weight). Because of the narrow applications we don't have a recommended alternative to the Mobil fluid.
Recommended replacement interval: 30,000-40,000 miles
Shop MTL for BMW Manual Transmissions:
Red Line MTL |
1990s-2000s 5-speed and 6-speed ATF (excluding E46 M3, E9X M3, Z4M)
From the mid-1990s, nearly all BMW manual transmissions, except 6-speed M models, use a Dexron III ATF oil, indicated by an 'ATF' label on the transmission. You can find a Dexron III spec almost anywhere but we are impressed with the performance of Red Line ATF D4 in manual transmissions. In our experience, it outperforms even fresh factory fluid, especially in colder temps. For track use, an ATF may become too slippery at high temps, in which case we recommend the Red Line MT-LV which has a slightly heavier weight that holds up better.
Recommended replacement interval: 30,000-40,000 miles
Shop ATF for BMW Manual Transmissions:
Red Line ATF D4 | Fuchs ATF D4 |
2000s-2010s M 6-speed and SMG (not DCT) MTF
This is the era that BMW started using 'Lifetime' fluids, indicated by a 'MTF' label on the transmission. The 'Lifetime' has never been fully explained and we don't buy into it, especially when fresh fluid typically makes a huge improvement in shift quality and smoothness. The fluid formula has changed over the years - MTF-LT-1, LT-2, LT-3, LT-5, and FFL-4. There are discernible differences between them and LT-2 has the strongest following among enthusiasts. Our observations are that these LT fluids are acceptable in normal day-to-day driving and in cold temperatures but are permanently affected by high temps, such as on track. We have found that the Red Line MT-LV is superior than ATF D4 and factory MTF for these cars in all conditions. SMG transmissions use the same MTF oil as the manual transmissions, however, the SMG Hydraulic Pump uses Pentosin CHF 11S hydraulic fluid.
Recommended replacement interval: 30,000-40,000 miles
Shop MTF for BMW Manual Transmissions:
Red Line MT-LV | BMW LT-2 | BMW LT-3 | BMW LT-5 |
2000s-2010s DCT
The Double-Clutch transmission uses a set of two clutches that are 'wet' clutches. The clutch discs are immersed in the same oil used to lubricate the transmission internals. The wet clutch system ensures smooth operation and engagement. BMW requires a special DCT-specific fluid, although they also label it as 'Lifetime Fill'. We don't buy in to the lifetime fluid policy and have experienced the benefits of fresh fluid on our daily and track cars.
The OEM DCT fluid is made by Pentosin and works just fine for normal street use. Red Line DCTF is an upgraded formula that works on normal street cars and holds up better for sustained track time. With more power or higher heat the fluid thins out and breaks down which causes the clutches to slip. A stronger oil like the Red Line fluid will not break down as easily at higher temps.
Recommended replacement interval: 30,000-40,000 miles
Shop DCTF for BMW:
Red Line DCTF | Pentosin DCTF |
BMW Automatic Transmission Fluid
Note that changing the fluid on automatic transmissions can be a very technical process that requires a precise procedure, special tools, and/or professional-level diagnostics software. There is no doubt that fresh fluid will perform better than used and dirty fluid. However, most of the problems we hear come from an improper transmission flush where particles and debris block fluid flow or from failing to set the correct fluid level after. We believe automatic transmission fluid service should be left to a professional BMW technician and that extended fluid service (>50,000 miles) is acceptable as long as the fluid level is regularly checked and maintained.Vintage 4-speed auto
ATF Dexron III is the fluid standard for 4-speed BMW automatics (ZF 4HP). This is also the most common ATF you will find at auto parts stores (it's compatible with most GM and Ford auto transmissions).
Recommended replacement interval: 40,000 miles
Shop ATF for BMW Automatic Transmissions:
Red Line ATF D4 | Fuchs ATF D4 |
1990s-2000s 4- & 5-speed auto
BMW 4 and 5-speed automatics are made by either ZF (4HP) or GM (5L40-E/A5S360R). The recommended ATF for either is Dexron III (D4). This is also the most common ATF you will find at auto parts stores (it's compatible with most GM and Ford auto transmissions). BMW has transitioned to a newer Dexron VI spec, which is backwards compatible with Dexron III. If your car is serviced at the dealer they will likely install D6. BMW recommends using only the same fluid in the transmission when topping off the oil level. They do not recommend mixing ATF oil brands and specs so keep track of what oil is in your transmission.
Recommended replacement interval: 60,000 miles
Shop ATF for BMW Automatic Transmissions:
Red Line ATF D4 | Fuchs ATF D4 |
All 6-speed auto
The BMW 6-speed automatic is made by either GM (6L45/6L50) or ZF and was used mostly in mid-2000s RWD and AWD models. BMW used the ZF GA6HP19, GA6HP26, and GA6HP28 throughout the model range. Contrary to what's written online, the ZF 6HP can be serviced with a full oil pan and gasket kit available. However, professional servicing is recommended due to the precise procedures required. The OEM ATF is a ZF Lifeguard 6 which carries a Dexron VI (D6) rating. BMW refers to it as 'ATF 2'. Cars that originally used D6 cannot use D4 (all 6- and 8-speed automatics) so keep track of what oil is in your transmission.
Recommended replacement interval: 80,000 miles (BMW's estimate is 100,000 miles)
Shop ATF for BMW 6-speed Automatic Transmissions:
Red Line ATF D6 | BMW ZF Lifeguard 6 ATF 2 | Pentosin ATF D6 |
All 8-speed auto
The BMW 8-speed automatic is made by ZF and was used mostly in mid-2010s RWD and AWD models. BMW used the 8HP45, 8HP50, 8HP70, 8HP75 throughout the model range. The ZF 8HP can be serviced with a full oil pan and gasket kit available. However, professional servicing is recommended due to the precise procedures required. The OEM ATF is a ZF Lifeguard 8 which carries a Dexron VI (D6) rating. BMW refers to it as 'ATF 3'. Cars that originally used D6 cannot use D4 (all 6- and 8-speed automatics) so keep track of what oil is in your transmission.
Recommended replacement interval: 80,000 miles (BMW's estimate is 100,000 miles)
Shop ATF for BMW 8-speed Automatic Transmissions:
Red Line ATF D6 | BMW ZF Lifeguard 8 ATF 3 | Pentosin ATF D6 |
BMW xDrive Front Differential and Transfer Case Fluid
BMW Xi and xDrive models use a center transfer case to distribute power to the rear and front axles. This is a chain-driven transfer case mounted on the back of the transmission with a driveshaft extending from the front and rear of the housing. The front differential is a traditional hypoid gear design very similar to the rear differential but in a smaller size.Center Transfer Case
1999-2003 325Xi/330xi and X5 Models (NV Transfer Case)
BMW recommendation: ATF Dexron III rated
Our recommendation: Red Line D4 ATF
Recommended replacement interval: 50,000-60,000 miles
Shop ATF Transfer Case Oil:
Red Line ATF D4 | Fuchs ATF D4 | BMW DTF-1 |
2003-present xDrive Models (ATC Transfer Case)
BMW recommendation: DTF-1 (previously TF0870) 75W GL-4
Our recommendation: same as BMW. The ATC transfer case has a proprietary blend and we do not offer an alternative at this time.
Recommended replacement interval: 50,000-60,000 miles
Shop DTF Transfer Case Oil:
BMW DTF-1 |
All Front Differential
BMW recommendation: SAF-XO, 75W90 weight, GL-5 rated
Our recommendation: Red Line 75W90
Recommended replacement interval: 40,000-50,000 miles
Shop Front Axle Gear Oil:
Red Line 75W90 | BMW SAF-XO 75W90 |
BMW Rear Differential Gear Oil
BMW rear differentials are either open without a limited-slip feature or with limited-slip (posi-traction). Nearly all non-M models use an open differential and rely on traction control to limit wheel spin. Vintage models and M cars use some form of limited-slip - clutch-type, viscous, or Torsen designs.The ideal operating temp for diff oil is 150°F. If you exceed this at the track you may want to invest in a diff oil cooler which will also increase capacity. You can move up to the next highest weight (90 to 110) but realize there may be other consequences including limited slip behavior or not reaching your optimum temp.
Vintage-1990s Open or Limited-Slip Differential
BMW recommendation: SAF-XJ, 75W140, GL-5 rated*
Our recommendation: Red Line 75W90 or 75W110
Recommended replacement interval: 40,000-50,000 miles
* - The SAF-XJ synthetic fluid replaces the previous factory recommendation of SAF-XLS mineral oil for clutch-type limited-slip differentials. This must have been part of a larger effort to switch to full synthetic instead of mineral-based oils. The 75W140 weight is strange to us but it's the only gear oil listed in BMW's official fluid guide for these differentials. We have used Red Line 75W90 in just about everything with great results and have adopted the new 75W110 for hot climates or heavy track use.
Shop 75W90 Rear Axle Gear Oil:
Red Line 75W90 | Red Line 75W110 | BMW MSP 75W140 |
Rear Open Differential, before 7/2011 production
BMW recommendation: SAF-XO, 75W90 weight, GL-5 rated
Our recommendation: Red Line 75W90
Recommended replacement interval: 40,000-50,000 miles
Shop SAF-XO Rear Axle Gear Oil:
Red Line 75W90 | Red Line 75W110 | BMW SAF-XO 75W90 |
Rear Open Differential, after 7/2011 production*
BMW recommendation: G1 synthetic, 75W85 weight, GL-4 rated
Our recommendation*: BMW G1 if under warranty, Red Line 75W85 GL-5 (Red Line-approved)
Recommended replacement interval: 40,000-50,000 miles
* - BMW curiously switched gear oils from 7/2011 without any changes to the differential itself. Normally, GL-4 and GL-5 oils should not be mixed. They are incompatible with soft metals such as brass, used in high pressure applications like a transmission. The differential does not see the same high pressures and Red Line has approved their 75W85 GL-5 oil as an alternative to the factory GL-4. The fully-synthetic base oil from Red Line will cling better to metal surfaces and have greater strength especially when temperatures rise.
However, failing to use a GL-4 oil may cause warranty issues if you make a claim for differential/rear axle work. Any fluid other than the factory-approved type will likely void the warranty for that particular part. If you wish to stay compliant the factory GL-4 is your only choice. Red Line also makes a GL-4 75W85 oil (MT-85) but their official recommendation is the GL-5 75W85 because its additives and formula make it a better overall oil.
Shop G1 Rear Axle Gear Oil:
BMW G1 75W85 GL-4 | Red Line 75W85 GL-4 | Red Line 75W85 GL-5 |
Rear 2001-2013 M-Variable Limited-Slip Differential
BMW recommendation: SAF-XJ+FM, 75W140, GL-5 rated
Our recommendation: Red Line 75W140
Recommended replacement interval: 40,000-50,000 miles
Shop M-Variable Diff Oil:
Red Line 75W140 | BMW SAF XJ+FM 75W140 |
Rear 2012-present M-Active Electronic Limited-Slip Differential
BMW recommendation: MSP/A 75W140, GL-5 rated
Our recommendation: Red Line 75W140
Recommended replacement interval: 40,000-50,000 miles
Shop M-Active Diff Oil:
Bmw Rebuilt Transmissions For Sale
Red Line 75W140 | BMW MSP/A 75W140 |
Rear M Performance Limited-Slip Differential (F22, F30, F32, etc):
BMW recommendation: hard to say because BMW does not publish a replacement fluid. We think it's MSP/A 75W140 (same as used in M Active diffs).
Our recommendation: Red Line 75W90 or 75W110
Recommended replacement interval: 40,000-50,000 miles
Bmw Smg Transmission Review
Shop M Performance Diff Gear Oil:
Red Line 75W90 | Red Line 75W110 | BMW MSP 75W140 |
Rear Custom Differential
Through our friends and diff experts at Diffsonline, we offer custom-built performance differentials. These diffs are usually built with some form of a limited-slip feature, using traditional clutch discs, a viscous unit, or helical gears. Below you will find fluid recommendations for each.
Recommended replacement interval: 40,000-50,000 miles
Traditional clutch-type: Red Line 75W90 for moderate street use; Red Line 75W110 for aggressive street and/or track
Factory BMW M Variable: Castrol-BMW SAF XJ+FM or Red Line 75W140
Diffsonline Helical: Red Line 75W110
Quaife: Red Line 75W110
Wavetrac: Red Line 75W110
OS Giken: proprietary OS Giken-branded 85W250
Kaaz: proprietary Kaaz fluid
Shop Custom Diff Gear Oil:
Red Line 75W90 | Red Line 75W110 | Red Line 75W140 | BMW SAF XJ+FM 75W140 |
Red Line 'Non-Slip' NS Gear Oil
Red Line produces a Non-Slip version of their 75W90 and 75W140 gear oil. This fluid does not contain friction modifier additives and will make the clutch plates engage quicker in limited-slip diffs. This is good for track use but will be noisy for regular street use.
Terminology & Acronyms
Below are some explanation of the scientific terminology, jargon, and acronyms commonly used when discussing BMW transmission and differential axle fluid.
| Dexron | Dexron is actually a trade name used by General Motors (GM). GM and ZF are the original designers and suppliers for automatic transmissions to BMW (and many others). Dexron has been their brand-name for ATF since the 1960s but the specs have been adopted industry-wide. The chemical formula has evolved over the years and BMWs use the Dexron-III spec. Dexron VI is backwards compatible to Dexron III, however, III cannot be used in place of VI. |
| GL | 'GL' is a rating used to differentiate various grades and formulas of gear oil. The American Petroleum Institute (API) issues GL ratings. The fluid must be compatible with the various metals used in transmissions and differentials. So while a higher GL rating means better fluid shear resistance, it may be harmful to certain types of metal (brass synchro rings for example). Pay close attention to the bottle label to verify the GL rating. BMWs usually use a GL-4 in transmissions and GL-5 for differentials but there are exceptions (see above). |
| Hypoid | A type of gear set where one gear is at a right angle to the other. These are the types of gears used in BMW differentials - an input shaft (pinion) contacts a crown wheel, which is connected to each axle shaft. The pinion and crown are at right angles to one another. The term is most often used in 'hypoid gear oil'. |
| MTL vs. MTF | Manual Transmission Lube and Manual Transmission Fluid. Both are for manual transmissions but due to the chemical differences there is a need to differentiate which cars they apply to. 'Lube' is for vintage models and 'Fluid' is for newer cars (late-1990s and newer). |
| Viscosity | The rating for the internal friction of fluid dependent on temperature. The SAE assigns the grade based on two temperature standards: cold (the “W” in 75W90) and high 100°C (212°F). These are grades based on a system devised by the SAE and not a measurable value (see cSt below). It means the oil performance aligns with a particular grade in the SAE system. The higher the number, the thicker the oil and the longer it will take to reach operating temperature. However, it does not mean that a MT-80 is twice as thick as a 10W40. It's only an assigned rating. For actual measurable values, viscosity is expressed in centiStoke units (1 cSt = 1 mm2/s) and measured at two different temperatures: 40°C and 100°C (212°F). A higher cSt is a thicker oil, giving more protection but less efficiency. However, a low viscosity does not automatically mean less protection (the chemical makeup of the oil determines that). CentiStoke values are not as commonly referenced for gear oil as they are for engine oils. |