TESTED: BG Syncro Shift II Gear Oil
S550 Mustang MT-82 drain plug
Once loosening the fill plug, the next step is to loosen the drain plug using the same 8mm hex.

BG Products, Inc. is committed to maintaining vehicles through high quality automotive maintenance services for fuel systems, engines, transmissions, brakes, power steering, cooling, battery, drive line and climate control systems.  They provide the highest quality products and equipment to dealerships, independent shops and franchises so they can perform BG Automotive Maintenance Services on consumer vehicles.  BG goes as far as training technicians on proper procedures for performing their services through their own BG University which was founded in 1999 and an online BG Certified Service Advisor Training that started in 2011.

Manufactured in El Dorado, Kansas, and distributed all over the world, BG’s professional-use products and equipment add more efficiency, miles per gallon and long-term reliability to vehicles. Their vision is to provide the highest quality products, services and solutions for transportation and related industries worldwide.  Unique to the industry, BG Products works, as it always has, through a close-knit network of independent distributors.

S550 Mustang MT-82 draining fluid
With 5,000 miles on the Royal Purple Synchromax, the oil still retained the majority of its signature purple hue.

Through extensive testing, OPMustang.com found that BG Syncro Shift II Synthetic Gear Oil is one of the few products that have been proven to work very well in the troublesome MT-82.  While Automatic Transmission Fluids (ATF) are often recommended in manual transmissions for their light viscosities, they suffer from low film strength, induce severe fluid shearing, and greatly sacrifice wear protection.

S550 Mustang MT-82 BG Syncro Shift II Oil
Once the oil was drained and the drain plug tightened.  We were ready to fill the MT-82 with BG Syncro Shift II.

BG Syncro Shift II is a gear oil that is specially formulated for manual transmissions, transaxles, and transfer cases and provides outstanding extreme pressure characteristics, film strength, shear stability, wear protection, and seal compatibility without sacrificing low temperature fluidity or performance characteristics. It may be used in all domestic and import vehicles where engine oil, ATF or GL-4 gear oil is specified for manual transmissions and is suitable for:

-FORD XT-11-QDC Spec.


-GM PN 12345349 (specification 9985648)

-FORD PN D80Z19C547A,



While viscosity ratings, indexes, flashpoints, and other metrics don’t tell you anything about the quality of the base oil stock, additive packages, lubricity, etc… let’s look at how BG Syncro Shift II stacks up against some common transmission fluids:

BG Syncro Shift II

cSt @ 40*C – 37.85

cSt @100*C – 7.11

Flash Point – 212*C (413*F)

Pour Point -43*C (-45*F)

Viscosity Index – 153

SAE Viscosity Grade (Motor Oil) – 5W30

SAE Viscosity Grade (Gear Oil) – 75W80

RP Synchromax

cSt @ 40*C – 38

cSt @100*C – 7.7

Flash Point –420*F

Pour Point -66*F

Viscosity Index – 175

SAE Viscosity Grade (Motor Oil) – N/A

SAE Viscosity Grade (Gear Oil) – N/A

Redline D4 ATF

cSt @ 40*C – 34

cSt @100*C – 7.5

Flash Point – N/A

Pour Point -60*C (-76*F)

Viscosity Index – 198

SAE Viscosity Grade (Motor Oil) 0W20

SAE Viscosity Grade (Gear Oil) 70W80

Redline MTL

cSt @ 40*C – 54.1

cSt @100*C – 10.4

Flash Point – N/A

Pour Point -50*C (-58*F)

Viscosity Index – 185

SAE Viscosity Grade (Motor Oil) – 5W30

SAE Viscosity Grade (Gear Oil) – 75W80

Lower Viscosity Index = Greater the change of viscosity of the oil with temperature.
Here we see at 40*C (104*F), BG Syncro Shift II is actually thinner than Royal Purple Synchromax and Redline MTL, however it is a bit thicker than Redline’s D4 ATF.  At 100*C (212*F), a typical operating temperature, BG Syncro Shift II is the thinnest of the bunch with a similar flash point to Synchromax, but the highest pour point of -45*F (the temperature where a liquid becomes a semi-solid and loses its flow characteristics.


    1. It’s hard to generalize and really depends mostly on the use of the car. For the street (and even occasionally tracked car), it’s typical to change manual transmission fluid every 30K miles, but most go much longer than that (I’ve seen some cars go 60-100K) with no issue. The more you track your car and the hotter the transmission runs, the sooner you should change your trans fluid. Unless it’s a dedicated track car, even with a good amount of weekends, every 15K is probably more than enough.

  1. I’ve have seen comments that the Redline DCTF is as good or better than the BG Syncro shift 2. Any opinion on that fluid and is it suitable for the mt-82?

  2. I read reviews on some Mustang forums stating that the BG Syncro Shift II may be a little too thick at 75W, even though it matches the FORD XT-11-QDC Spec . Is this a problem? I own a 19 Ecoboost Premium PP 6 SP MT and was considering replacing the factory fluid.

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