https://www.cmegroup.com/trading/en...CL§or=CRUDE+OIL&exchange=NYM&pageNumber=1
Front month crude is at $4000. They are currently at $4360 overnight with $6540 intraday and overnight initial.
Seems reasonable to me considering recent volatility (I only paid $600 in margin on my latest CL spread - consider spreading?)
https://www.interactivebrokers.com/en/index.php?f=26662
IB can set their margins to whatever they want iirc, as long as they dont go below CME mandate.
Crude has been very volatile since the Saudi oil field attack and so margins were likely pushed up (by CME) to compensate for the increased risk.
https://www.ampfutures.com/trading-info/margins/
Margins at AMP are around $4457.
https://www.cannontrading.com/services/futures-trading-margins
Overnight crude at cannon is $4400.
I don't know where you're getting "5x" from. Day trade margins are still relatively low across the board at futures-specific brokers.