Oil (commodity) speculation provides a service to those who manage costs for business. When one speculates on a price for a commodity they "bet" (gamble or risk) the price will be higher in the future than their offer (contract) on that date of the speculation. If it is, they have product below market value and can make additional money on the good "bet".
Their goal is more generally to control the cost of product out into the future (thus the terms Futures) so that the other areas of business can then be managed on that future cost. They can negotiate wages, prices and other contracts based on the cost of the Futures product which they have fixed by buying the futures contract.
Dodge is offering $2.99/gal gas for 3 years if you purchase their vehicle. If you buy that vehicle you have in effect bought a futures contract negotiated with Dodge. If the price of gas goes to $5/gal you really make out. But what if the price of fuel goes down to $2.50/gal? Dodge will still give you credit for your fuel puchases but still at the $2.99 price so then you lose or at least you don't get the benifit.
Absolutely Dodge has bought enough oil futures contracts to cover the expected fuel usage of this promotion. They knew before the promotion exactly what the promotion is going to cost. Participating in the futures markets provides them that knowledge.
Futures traders are our friend as they take the wild swings out of the commodities market. They just bet on the prices based on all the variables they put into their computer models.
Oil is like air or water or any other compound element. We are not going to run out. How we capture it is the thing that will change.