TESTED: BG Syncro Shift II Gear Oil

Changing out the factory transmission fluid for a higher performance oil is a common solution to reduce the notchy-ness and improve shifting feel.  This is especially important in the Getrag MT-82 used in the 2011-2017 Ford Mustang. While we already changed out the trans fluid in our test car, Tim at OPMustang.com said I “HAD TO” try the BG Syncro Shift II Synthetic Gear Oil. I wasn’t really motivated since the current Royal Purple Synchromax was already a big improvement over stock, but Tim offered to buy me a steak dinner if I didn’t think there was an improvement, so I gave it a try.

OPMustang.com has been around for nearly 20 years as a wholesale and direct mail order Speed Shop and marketer of Aftermarket Performance Products with the philosophy of “Service and Value Leader in Performance Parts”. While they offer all brands of replacement and performance products for all makes and models, they specialize in catering to the 2015+ S550 Mustang. They personally put all the products they sell to the test at the track to better educate and serve the consumer, rather than simply repeating the labels on the products like many speed shops do.

OPMustang.com is now a stocking dealer for BG Products and are offering a comprehensive S550 Mustang MT-82 Manual Transmission Lube Kit, which will also work on all 2011-2014 S197 Mustangs. They claim that the BG Synco Shift II will greatly enhance the shifting of the Mustang and improve cold shifting issues.

BG Syncro Shift II Kit from OPMustang.com
Tim from OPMustang.com sent us this very nice and comprehensive transmission fluid kit, which includes the BG Products Syncro Shift II synthetic gear oil, an oil transfer pump with storage bag, a measuring cup, and highly detailed step-by-step printed instructions with colored pictures that makes the installation a breeze for the casual DIY-er with the most basic skills.


The Chinese-made Getrag MT-82 isn’t known for being the best shifting gearbox in the business, especially for the 2011-2014 S197 Mustang crowd.  Fortunately, Ford made a lot of small changes to the transmission in 2015 for the all-new S550 Mustang Chassis, revising the hardware, clutch springs, gear finishes, shifter bushings and bracket, and oil specs to greatly improve shifting feel.  However, the MT-82 in our 2016 Mustang GT feels like you’re stirring a bowl of cake batter when shifting (most stock transmission fluids from BMWs to Camaros have this thick, viscous feeling).  There’s quite a bit of resistance as the synchronizers mesh together before dropping in to gear, especially when shifting from 1st to 2nd and this problem is even worse when the transmission is cold.

A common solution is to change out the transmission fluid for something thinner like Royal Purple Synchromax.  About 5,000 miles ago, we drained our trans and put in almost three quarts of Synchromax.  I immediately noticed a difference and the shifter didn’t have as much resistance before dropping into gear.  Shifting effort was a little lighter as if the bowl of cake batter was thinned out and less viscous.  From my experience, this improvement is consistent across many different cars when switching to a lighter high-performance oil.  The notchy feeling when shifting to 2nd was greatly improved but was still there. Overall, the shift action felt a little more bolt-action and less ‘gummy’.

S550 Mustang MT-82 transmission fill plug
The first step when changing out the transmission fluid in any car is to loosen the fill plug first.  If you strip out the fill pluge after draining the transmission, you can put yourself in a very bad position.  It’s best to make sure you can fill the transmission before draining it.  Both the fill and drain plugs use an 8mm Allen/hex bit.

I was perfectly happy with the improvement from Royal Purple and felt it was a must-do for every Mustang owner.  I wasn’t motivated to try something new since I’ve back to back tested Synchromax with Redline Oils, GM Synchromesh, Mobil 1, Motul, etc… in many different platforms and to be honest, almost every performance transmission fluid is going to be better than the factory fill.

One size doesn’t fit all.  Due to the differences in materials, design, and construction, some transmissions may like Synchromax better than Redline MTL, while others need a Redline MT-90 or Shockproof and grind gears with lighter oils like Synchromax or Redline MTL.

Unfortunately, it’s difficult to sift through the reviews of various oils on the internet since most performance oils will work better than stock, and most people don’t have the experience, time, and money to do proper back to back tests for every car out there.  In most cases, people tend to defend and promote what they use even if they have no personal experience with a differing product.

But, I digress. A steak dinner motivated me enough to try BG Syncro Shift II Synthetic Gear Oil. I wasn’t that familiar with BG Products and looked them up to find out that the company has been around for 46 years and founded by six entrepreneurs and WWII veterans who wanted to sell superior quality automotive products.


    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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