Also after using the GW 120xp flex head torque wrench, I like it a lot now. The best thing about it is that
(1) 120xp, it does help a lot in tight corners, which seems a small possibility event until I finally came across it once recently.
(2) Flex head. That is great.
(3) Don't need to loosen and tighten the knob to lock into a certain torque. Once the collar is released, the torque setting is fixed. It won't go anywhere.
(4) In theory, it is not necessary to store it in the lowest torque setting. However, the wrench will only go into its box at around 20 ft lbs. That kind of forces me to set to it to that value, which is kind of good.
Here is my original review.
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You cannot believe how happy I am!

Just when I am worried about torquing the spark plugs on my Subaru, I received this flex head torque wrench. Here is a picture showing how valuable it is to have a TW with a flex head. All my other TWs have fixed heads. This new addition definitely upped my game by a huge amount! All my other TWs just won’t work.
Using the GW 85188 TW is overall similar to using other TWs with some interesting differences. First there is not a nob at the end of the handle to enable or disable adjustment. Instead, there is a metal collar. Pulling down the collar will enable adjustment. Once the desired setting is reached, releasing the collar will lock. This is a bit awkward when I have to adjust the setting from the lowest 5 ft lbs to 75 ft lbs. Holding down the collar seems a bit of a hassle. However, at the same time, I do not have to worry about forgetting to lock down the torque setting by turning the nob at the end of the handle. Overall, I like this design because I like to have different kind of tools. When precision is the paramount goal, maybe it is reasonable to sacrifice a bit of convenience. The torque setting is accurate up to 0.5 ft lbs. It can be set to something like 25.5 ft lbs. But not 25.4 ft lbs. The collar will not lock outside of 0.5 ft lbs intervals. Another notable feature is that there are two lines in the center of the handle clearly marking the place where force should be applied. That is neat.

It is heavily promoted that the torque wrench is accurate within +/-3% of the torque setting. Once I read the instruction more carefully, this high accuracy only applies to the top 80% of the torque range. The full torque range is 5-75 ft lbs and that implies the TW is only super accurate in the 19-75 ft lbs range. Within the 5-19 ft lbs range, we are not sure about the accuracy. However, in the Certificate of Calibration, the TW is tested at three settings, i.e., 15/45/75 ft lbs. The results for the 15 ft lbs are really interesting and important because that cover most spark plugs. For my TW, the actual readings for the 15 ft lbs setting are 15.15, 15.15, 15.15, 15.2 and 15.2. That translates to torque errors of 1%, 1%, 1%, 1.3% and 1.3%. The average accuracy is about 1.1%. That is even closer than the 3% promoted for the top 80% of the range. (In case you are interested, the average accuracy readings for the 45/75 settings are 0.09% and 1.25%.) It seems that this TW might be a lot more accurate than advertised with the most accurate part being in the middle of the range. The accuracy at 45 ft lbs is a lot more than at both 15 ft lbs and 75 ft lbs. Another interesting observation is that among all the 15 tests, only 1 test shows that the actual torque is less than the intended torque spec. That makes a lot of sense because TYPICALLY slightly higher than spec is more desirable than slightly lower than spec. Therefore, when making these torque wrenches, GearWrench probably set the target torque slightly above the required torque spec. Otherwise, it would be difficult to explain that out of 15 tests, the actual torque is lower than spec only once.
There are a few other places where it is quite interesting
1 I looked over the instruction several times and I did not notice that the TW needs to be stored at its minimum torque setting, which is a common requirement for other TWs. That certainly makes life easier.
2 In the Certificate of Calibration, the stamp shows ‘SATA QC3’. This shows that most likely these TWs were made in the SATA factory. However, I have bought SATA tools in the past, and I consider them of lower quality than GearWrench. Coming out of the same factory does not imply the tools are of the same quality.
Possible improvements
1 I think it maybe a good idea to use a normal 90T ratchet head rather than the 120XP design with dual 60T paws. When access is an issue, a thinner head is more desirable than one additional degree of swing.
2 It would also be nice to add more flex positions. As of now, there are only three positions where the flexible head can stay with the help of a ball bearing. That seems a bit restrictive. Typically flex head ratchets with similar design have five such positions. In fact, it would be REALLY desirable if GearWrench can equip this TW with a locking flexible head. That would certainly add more flex positions and the locking feature is especially desirable on a torque wrench where you really want to make the ratchet steady while slowly applying torque.
3 Finally, I was a bit disappointed that there are a couple of typos in the instruction material. I can only read English. There is an obvious typo in the formula to adjust torque spec when used with an extension. There is another, less significant, typo in the example on how to operate the TW to adjust torque setting values. Finding typos in a manual is a big issue for me. It dampens my enthusiasm quite a bit.