Standard CDs only allow 74 minutes of play back time but most modern players will play back 80 minute ones also. These cds will allow 47 tracks but the songs would have to be very short. ie 80/47= 1m 42secs
Hunter I can tell the math was not your favorite. As Pablo said a cd has 80 minutes or 700 MB either way if you add your songs time or size won’t fit on one cd and may I ask you why have to be one cd? If you want to save it from your HD the story is different.
I have been trying to burn 47 songs on to one cd that can be played in any cd player.Can anyone tell me how to do it? I can make a MP3 cd but it will not play in my car.Can it be done and how?
Save your 47 tracks as low quality mp3, perhaps with the low bitrate of 90, certainly much less than 128.
When they are saved as a low bit rate, you can then rip them back to Audio, they will be the same length of track, but will only occupy a small ammount of space on your CD.
Hahahahaha! Nice theory, honest_me. But you are completely missing the point, which is, that an 80 minutes CD will only store 80 minutes of music. Doing what you suggest will only result in 80 minutes of music... rather poor quality music, that’s all!
Still, I HAVE actually done this.
I burned two albums onto CD (a total of 58 songs) and can play them in any CD player. These are the two albums:
The Residents - Goosebump (18 songs) 
The Residents - Commercial Album (40 songs) 
However, the total play time of these two very strange musical delights is only 76 minutes. Wonderful!
Seriously though--I highly recommend that you make the transition to a DVD-capable MP3/CD player in your car, with USB connectibility. No more need to carry around large numbers of CDs in your car when one DVD data disk can hold 60 albums!
To have as many songs on one disc:
Make sure your Disc player can play .mp3, and make sure your audio files are .mp3. If they aren’t make sure to either have a disc player that supports play-back of that file type or convert to .mp3.
Now, fire up your disc burning program and select data mode.
After that select the files to add and burn away.
The disc should be playable, it is on this end.
135 Rock songs on disc 1 and another 125 hip hop songs on Disc 2.