I am pretty sure my car has LSD, but I thought they didnt start doing it until 2017. Anyone else notice this on their 2016??

 

If someone were to add one on, maybe....A LSD did not come on the car from the factory until MY18.

 

Soooo... I did this today.. Do the rear diffs in Lexus work different than other brands, or is this an LSD?

 

Open diff cars can still burn both tires. Especially if its a flat even surface. If you turn a little and the weight over the rear tires becomes uneven, it will turn into a one wheel peel.

 

2016 IS did not have a factory option for LSD...so for sure if the rear diff. is stock it does not have it.
Having said that, I'm not sure if through the software they have not tried to mimic the functionality of LSD. Unfortunately I couldn't find any information that speaks to this either way.
The function of LSD is to transfer power to the wheel that has traction and away from the wheel that doesn't.
Aside from having an actual mechanical LSD, this could be recreated by simply applying enough brake force to the speeding wheel, which will inevitably cause power to be transmitted to the wheel with traction.
As the car has ABS, this could be done fairly easily as each brake circuit is connected to the ABS actuator.