What was the total size of the rendered video & audio streams?
Keep in mind that, although a DVD claims to be able to store 4.7 GB, in reality it’s only 4.3 GB.
You also need to make sure you’re looking at the correct file size.
For example, a recent project I did claimed to be 3.90 GB in size. In Detail mode, it said 4,096,552. Right-clicking on it and selecting Properties said 4,194,869,248.
This last figure is the one to use for sizing.
What bitrate did you use for the render?
According to the bitrate calculator I use, a 1 hr. 50 min. video works out as follows. This assumes AC-3 audio.
VBR: 8,700,000 / 5,000,000 / 3,000,000
CBR: 5,000,000