The exchange requirement is $5000/contract. If you have $9G your risk management techniques should give you the answer you seek.
However any suggestions with your $9G that you can trade up to 9 CL contracts with $1000 margin even if daytrading is foolhardy. Go ahead and try it you wont forget the lesson.
With $9K better you look at trading the the mini - CL at half the normal contract size. Ticker symbol is QM.
Your broker will give you the answer but most brokers will allow 50% day trade margin about $2500/contract.
But you dont really need a broker to tell you how many CL contracts can I day trade with $9G. The mere fact you are asking this question means you shouldn't be even thinking of trading. Do some homework and try a simulator to see what it means to hold 10 CL contracts with $9G margin.
take on 100 contracts and let it go outta control over night and then bust it out to see if you can bring it back. do this for a month strait.
The catch is the quality of the sim. if you use one that fills anything its useless. but if you use one thats close to 100% accurate with fills, you just might be on to something eh?