HHO gas car kits seems to be all the rage on the internet for the best increase in gas mileage. Some people are claiming gains of 100% or more but typical claims are in around 15-40% increase.
You may have seen it on TV or in the news but one experimenter entrepreneur is running his car on HHO gas and he even uses this technology for high temperature welding you can find the videos online on popular video sharing sites. This gas is not meant to totally replace gasoline but is more like a diesel or fuel additive in the sense that it is a supplement so you end up burning less gas.
There are other benefits from this water fuel cell technology sometimes referred to as hydrogen-on-demand besides your best increase in gas mileage. You may see increases in horsepower, quieter engine and reduced emissions, think about that passing an emissions test!
HHO generator kits do not come cheap but are well worth it. You can use them on trucks, diesel engines and some people are even using them on motorcycles, tractors and riding mowers. They do not require much in the way of maintenance usually just adding a few ounces of water every month or so.
These fuel cells do not take up much room under the hood of a vehicle and if you are handy with your hands or feel comfortable working around vehicles these are easy to install. If you want to know how to make a HHO gas generator or construct a fuel cell then you can find bits and pieces of free information online to build a generator. If you want to know how to build a HHO gas car kit it is best to buy the plans and get step by step instructions.
HHO gas car kits can be better than oil or gasoline additives to increase gas mileage. When you build or do it yourself you could save money on gas but will save hundreds of dollars on the kit and replicate the system for other vehicles you own.