So when I use Armory Crate, I realized that BeamNG uses about 98% of my GPU power, and this causes the temperature of my GPU to ramp from 35 to 80 quickly. Is there something wrong with my GPU? If you want to know what my GPU is, it's in my signature.
Umm, no. It just means that the GPU doesn't have to wait for the CPU. That's the optimal scenario because it give you the smoothest experience. Different games will have different load on the CPU and GPU so sometimes you won't see you GPU being utilized fully. High framerates with high GPU usage usually means that the game is well optimized.
I have a GTX 1080 ti that is overclocked and BeamNG uses about 87-90% of the GPU, my settings are everything on high at 4K and the temperatures never goes above 30°C over ambient. If your GPU is from Asus you can use Asus GPU Tweak III or other software to set a more aggressive fan curve and see if that helps, if not you should consider replacing the thermal paste and thermal pads on your GPU. I replaced thermal compounds on my old 1080 ti not to long ago and it did wonders for performance and temperatures.