One such fuel is liquefied petroleum gas (LPG). LPG has been used as automotive fuel (or autogas) for more than four decades in progressive and developing countries (such as Italy and South Korea), with eight million vehicles worldwide currently tapping LPG as the automotive fuel of choice.
Unfortunately the number of Philippine vehicles using LPG as autogas is insignificant; but with the stringent vehicle emissions (and the mandatory rules and regulations enforcing the law) stemming from the 1999 Clean Air Act, it is forecast that the use of LPG as automotive fuel will increase.
Petron Corporation has realized this and recently launched Petron XTend Autogas. Basically an installation of an LPG tank in the trunk, an LPG bypass valve (sitting on top of the intake manifold) and a conversion kit that enables one's engine to run on LPG, XTend Autogas surpasses other conventional fuels in terms of emissions (for example, 0.09 hydrocarbons and nitrogen oxide are emitted by XTend, unlike 0.14 hydrocarbons and nitrogen oxide emitted when gasoline is used). It also does not contain lead and very minute amounts of sulfur, contains less ozone- and CO2- forming properties, and prolongs the life of the engine due to the lack of acids and carbon deposits present when burning gasoline (which results in less wear and tear on the engine).
For those who have doubts about the safe use of "cooking gas" as autogas, one may consider the following: 1) LPG tanks are made of the highest quality steel and are tested to high pressure, which do not puncture easily and are manufactured in accordance with standards set by the international governing associations in automotive use of LPG; 2) LPG tanks are equipped with a device that automatically shuts off LPG flow when filling reaches 80 percent of capacity, which allows for temperature changes and prevents the release of gas from the tank; 3) Autogas engine fuel systems are fitted with safety devices, vents, magnetically controlled fuel sensors, heavy duty copper pipings and electrically controlled shut-off valves that function automatically in case of fuel line ruptures, thus preventing uncontrolled flow of LPG from the tank; 4) Autogas has the least flammability range (two to ten percent) of any alternative fuel, does not soak clothing and easily dissipates in the air in case of minor leaks because of an added odorant within the product; 5) Even at cold starts, engine performance is similar, with little emissions, no smoke, no carbon exhaust "smell", little engine noise and smoother combustion, eliminating the need for costly fuel additives.
To wit, Autogas has a simpler chemical makeup (mostly hydrocarbons, with 60-70 percent propane and 30-40 percent butane) which leaves very little carbon residue. Although it is found in liquid (pressurized) form when it is in the fuel tank, Autogas becomes a gas when it enters the engine, leaving less carbon deposits than gasoline or diesel. And speaking of gasoline, Autogas has a higher octane content than super grade gasoline, with the former at a 100 octane rating and the latter at 98.
Autogas can be used on four-stroke spark ignition engines can be converted to bi-fuel (Autogas and standard gasoline), including turbocharged and fuel-injected engines. This is done by adding a second independent fuel system to the vehicle, with the tank fitted to the spare wheel well or the trunk (occupying roughly one-third of the boot). The conversion costs about P26,000 (for carburetor-based engines) and P32,000 (for EFI-based engines) and can be completed in one day.
If warranty is a problem, Petron claims that vehicle manufacturers can only void the warranty in respect of the parts affected by the conversion, and capable conversion kit installers can provide additional warranties to cover these areas. If insurance is a problem, Petron recommends notification of one's insurance company if the vehicle has been converted; otherwise the cover may be invalidated.