The gradient you see on the screen in FulGaz is the exact gradient we send to your trainer. That applies for every second of every ride. So if it says 2% on the screen - that’s what got sent to the trainer. The data can be wrong of course, but generally, it's the best data you'll find for indoor training.
We also send your weight, drag number and the rolling resistance among other things. From there, the trainer works out the resistance.
If you've come from Zwift, it's default is to make the trainer feel half as hard as real life. compared to this, FulGaz can feel terrible at first because it's just not what you're used to. You can adjust how hard FulGaz feels without changing your speed. It's in Settings > Advanced trainer settings > Slope Scaling. This is the same as Zwift's "Trainer Difficulty" Try 80% (The Zwift default is 50%)
The other possibility, particularly if you seem to be going way too slow, is you have one of the settings wrong. Sometimes it’s something as simple as a person thinking they’ve added their weight in pounds but they’re actually using KG.
Double check you’ve got all the settings correct and things should feel really close. I usually advise against it, but it might even be worth deleting FulGaz and reinstalling it so you can guarantee everything is set to its default.
If all your settings are correct in FulGaz, we recommend doing a spindown before riding again. This is usually the cause of "it doesn't feel right" issues.
IMPORTANT NOTE ON SPINDOWNS AND CALIBRATION
Once you have done a spindown, it's really important to then quit that app before you use FulGaz. If you don't do this, your trainer will still be paired to that app and FulGaz will not work. In some cases you will also need to "forget" the trainer in the utility app.
Make sure you quit the utility app before reconnecting to FulGaz