Can LPG be used as fuel for cars?

Question

I have a petrol engine car but I want to know that can I use LPG as a fuel for my petrol engine. I know I have to do customization for it but can I use LPG in a normal Petrol engine or does it affect my car engine if I use LPG fuel is it a good idea ?

Answer 1

LPG burns hotter than petroleum (gasoline) in an internal combustion engine.

The running temperature of the engine as a whole is regulated, but the hotter exhaust gas can reduce the life of the valve guides and seatings.

You might need to adjust the ignition timing too, because the combustion propagates more slowly through the LPG fuel-air mixture.

Various discussions can be found, such as on this Lexus Owners Club Q&A site.

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Another potential disadvantage is that some ferry or road tunnel operators may have special requirements for LPG powered cars. Certainly at UK's Dartford tunnel vehicles with a dangerous cargo are directed to a layby, and periodically the tunnel is closed to general traffic while the convoy is escorted through. I'm not sure if this applies to LPG powered cars.

Brittany Ferries says:

Can I take my LPG / LNG vehicle on your ferry?
We carry both Liquefied Petroleum Gas (LPG) and Liquefied Natural Gas (LNG) vehicles on board all our vessels providing the vehicle is a recognised manufactured model with standard specification. The gas cylinder MUST be switched off prior to embarkation.

Which seems to exclude kit conversions, and how would you drive the vehicle on board if the gas is switched off? You would need the ability to run on dual fuel, which also means your LPG tank will take up a good proportion of the boot/trunk space.

You may also find that Eurotunnel does not permit LPG powered cars on the Channel Tunnel train crossing. Their website about The Carriage of Dangerous and Hazardous Goods and Hazardous Articles says

Hazardous goods
“Hazardous Goods” means any goods for personal use described as hazardous by ADR, and/or which by their nature or the method by which they are transported are, in Eurotunnel's sole opinion, liable to present a threat or hazard to the security and/or safety of Shuttle operations.
. . .
2.4 Carriage of the following Hazardous Goods is PROHIBITED:
. . .
2.4.2 Vehicles powered by or which run on Hazardous Goods including Liquid Petroleum Gas (LPG) (Butane or Propane), Liquid Natural Gas (LNG), Compressed Natural Gas (CNG) or any other flammable gas.

Answer 2

You can purchase LPG conversion kits for automobiles. Do a Google search and you'll see many available to you. It is a lot easier to do it for carbureted vehicles rather than fuel injected, but it's still possible. So, yes, you can use LPG in gasoline (petrol) powered engines.

LPG runs cleaner than gas, so there's that. According to this website, while LPG is about 20-25% less efficient than gas, it costs about 50% less, so overall it would be a savings to run. To answer the "is it a good idea" question would only be an opinion. That is completely up to you to answer for yourself.