Convert LPG Vehicles To Run On Liquefied Methane Gas

Although Liquefied Petroleum Gas (LPG) was recognised as a fuel option in 1910, it wasn’t until the 1973 global oil crisis that it became a viable option for retail use.

As LPG became more widely available as a more affordable and environmentally friendly fuel for cars in the early 1990’s and 2000’s, hundreds of thousands of Australians converted their cars to run on LP Gas.  

However, the number of LPG cars has been falling for the past ten or so years; in 2013, there were about 500,000 LPG cars driving around on our roads.   Automotive LPG sales have decreased over the past decade and now it only makes just 2% of all automotive fuels sold in Australia.   This info was in a report that I think came out from the NRMA.

The report continued by stating that the government provided rebates to owners who installed LPG systems on their cars or bought new LPG-fueled models, and that the market for dual fuel and full-LPG aftermarket systems exploded in the 2000s. But in 2014, the rebate offer was dropped due to years of poor participation. An excise was imposed in 2011 with a starting price of 2.5 cents per litre; as of right now, it is 1.36 cents. This lessened the cost benefits of LPG at a time when newer gasoline and diesel cars were becoming more fuel-efficient.

The technical sophistication of vehicle design has also increased. Basic LPG installation kits, for example, relied on straightforward electronic interface systems to work with the electronics of the vehicle and plenty of boot space to store the tank underneath or in the back. The readily available “one size fits all” kits turned out not to fit very many cars.

So now, I’m thinking about all of those LPG vehicles and why couldn’t we run them on Liquefied Methane Gas.   Australia has a huge amount of Methane beneath our feet, especially in NSW.  

Vehicles with internal combustion engines can run on alternative fuels like liquefied petroleum gas (LPG) and that’s a proven fact.  I’m thinking that theoretically, liquefied methane gas (LMG) should be able to be run in an LPG Vehicle. There would surely be some compatibility and comparable performance with the two options?   The problem is though, they have much different qualities and attributes.

LMG is primarily made up of methane (CH4), whereas LPG is a blend of propane and butane.  Because LMG has a higher energy density than LPG, it can store more energy per unit volume. LMG has lower emissions than LPG because it emits less CO2 and only a trace amount of other pollutants when burned.

But when it comes to LMG, it’s not all beer and skittles.  LMG has certain drawbacks in comparison to LPG. Compared to LPG, LMG requires a higher pressure and a lower temperature to liquefy, requiring more sophisticated and costly delivery and storage systems.

In addition, LMG has a lower octane rating than LPG, making it more likely to cause engine knocking or detonation, which can harm the engine and decrease its efficiency.

As a result, we can’t go out and start filling up LPG vehicles with LMG.   Cars designed to run on LPG will need to run on LPG.   Getting an LPG vehicle to run on LMG would not be easy at all.

The get a vehicle with an LPG set-up to run on LMG, these cars would require modifications to its fuel system, engine, and emission control system in order to accommodate the special features and characteristics of LMG. Let’s be honest, none of that sounds cheap at all.

It would also depend on the cost and benefits to the environment of using LMG instead of LPG, as well as how readily available and easily accessible LMG is as a fuel source.

In conclusion, it might be possible to substitute LMG in vehicles that have been made for LPG, but it is not going to be practical from what I can see or advisable.   The cost of all of the proper modifications and considerations might not make this idea financial viable.

I’d still like to see every vehicle running around on unleaded petrol being converted to run on LMG though.  

One can only hope.