They say that when you combine two things, there are in actuality three; each independent element and the interaction of them both. Such is the case with dual-fuel. Dual fuel is when you have both gas and electricity to feed your housing energy needs, but it can also denote a vehicle which runs on two types of gasoline. Hybrid vehicles can also be considered a type of dual-fuel vehicle even though you won't see them classified under Flex-Fuel automobiles (the common name used for cars running with a dual fuel engine). With such an advantage in fuel diversity, one would simply seek the cheapest dual fuel out there. However an important part is to examine dual-fuel prices against single fuel purchasing.

In housing, dual-fuel can be cheaper if an energy company sells you both. Some of them, but not all, may give you discounts on your energy bill, or lower the price of one or both fuel types as an incentive to bring you in as a customer. You can opt to sign up with two different companies, each one selling you one type of fuel; however the benefit of having one company is the lack of hassle when dealing with repairs, complaints and payments. In the end, to be rewarded the cheapest dual-fuel you will have to do some research into which companies offer what and their pricing. This will mainly depend on locality because there are various factors that affect energy pricing. The internet offers a quantity of companies where you can compare the costs among each.

When speaking of the cheapest dual-fuel in terms of Flex-Fuel vehicles things get trickier. The desire for cleaner, environmentally friendly vehicles is one of the healthier fads we have ever crazed. But a cleaner automobile doesn't make it any cheaper. Hybrid vehicles for instance are on average, given an $8,000 price tag over the original cost of a regular gas guzzling car. The reason for this is to compensate for the costs of all the gasoline you will not be buying. Question is who is benefiting here? Certainly not you. It doesn't sound fair, because it isn't. But that's oil lobbying for you.

Dual-fuel or Flex-Fuel vehicles trade this dilemma for another one; their miles per gallon. Dual-fuel cars can run on gasoline, ethanol or a mix of both. The problem with ethanol fuel is its lack of potency, thus it burns faster than regular gasoline. This means that you will have to make more regular stops at gas stations. And that itself is another problem. Unless you live in Brazil, you will find that there is a scarcity of ethanol fuel stations, especially in the United States. As of 2010 there are only 2,113 ethanol fueling stations in the country; in other words, they consist of 1 percent of all the fueling stations in the US. In the end, you will find the cheapest dual fuels in Brazil for the country has practically developed its automobile industry for it.

You will however find the cheapest dual-fuel during an oil crisis, as ethanol comes from sugar canes or maize; an energy field much easier to exploit. Hence the cheapest dual-fuel whether vehicular or for housing will truly depend on a great number of factors that must be scrutinized before one takes the leap towards the alternative energy.