For the OP: This page shows the initial and maintenance margin for the full size and mini contracts at IB. You might also run a quick calculation (margin/notional value) to see how much bang you're getting for your buck. https://www.interactivebrokers.com/en/index.php?f=margin&p=fut
Just because I've never quoted myself before , here's a table that shows relative leverage across full size, physical commodity contracts. The "initial" and "maint" margins are for trading that is speculative with positions held overnight. Of note: 1. There are large differences in the way IB and RJO view certain markets 2. Coffee, for the first time in a couple of years, now requires the greatest margin as a percent of notional contract value. Silver is still very close, which is odd because it's been so darn quiet recently and the price is nowhere near $30 or $40.