Does drafting work below 33 kph

Riding alone, 33 kph and above seems to be the speed that drops you into the aerodynamic position AND allows you, in a group, to draft maintaining a speed with less effort.
But does drafting in a slower group, at lets say 25 kph, also give you the drafting effect or do you need the minimum 33kpm

Yes, drafting works at lower speeds. You can see the effect (literally) when in workout mode. The end of interval barrier scooches ahead when you ride into a draft.

Thanks Jim. Appreciate the reply.
Ray

The answer is correct, drafting is present at lower speeds and it is quite noticeable but the proposed experiment is not valid.
When in work out mode, you can not draft.
Others may draft off a rider in a work out.
That is a rehash of the stated Zwift policy.
If it has changed, then my statement will be incorrect.

To demonstrate the draft, ride with a group of riders and go out front and note your watts.
Then, let the group go past you and see how much you can let your watts drop and still hang with the group.
It is a big difference.
I like to practice this on group rides where you can go full out because you should stay with the leader but I try to move up in the group while keeping my HR in zone 3 or so.

Don’t use the TT Bike or perform in a work out.

How do you explain the movement of the end-of-interval barrier when falling in behind another rider? If it isn’t drafting, it may as well be, because it has a very similar effect. For the same power output, you move at a greater velocity when behind another rider.

I really can’t explain this.
I’ve seen it occur too.
I have noticed it even when I’m not behind someone.
I attributed it to variations to my in game speed.

When ever I’m behind someone, I tend to pedal a little harder.

I have not specifically tested to see if drafting works in work out mode, I just took the Zwift user manual at its word.
Here is the relevant section under: advanced settings - using workout mode

While you’re in workout mode, you’ll notice some differences from how Zwift works when you normally ride.
•Your nameplate will show a graph icon on the left side.
•Your avatar will appear to have a holographic display in front of their bike.
•You can’t draft (but others can draft you).
•You won’t receive PowerUps.
•Your rider score XP increases based on workout intensity and successful intervals instead of distance.