Author Options:

What effects does running a gasoline engine with propane have? Answered

I know that propane will run a gasoline engine, but besides the hoses and seals drying out is there any massive loss in output or any other kind of wear on the inner workings?


I run a 3.5 litre V8 on LPG inside my Landrover 101FC, when it was professionally tested and tuned, we got slightly more power out of it than on petrol/gasoline !!

My high performance system runs, using a lambda probe in the exhaust to control the mixture via an electronic valve and microcontroller. I added a lambda meter to the dash too.

There is a slight problem with propane in some older engines, where the lack of lead or other lubricants in the incoming mixture causes valve seat recession. This can be fixed with a special dripper that adds a lubricant whent the engine is running. Modern engines don't need it though.

Propane for vehicles in the UK is 1/2 price or less than petrol/gasoline


> the lack of lead or other lubricants in the incoming mixture causes valve seat recession
.  IMNSHO, the best fix is to replace the valves and seats with modern, no-lead-needed components.


7 years ago

Assuming the engine is properly tuned and carbureted, there may be a slight loss in horsepower but propane burns cleaner and with less chance of pre-ignition and detonation than with gasoline. There is less CO, CO2 and unburned fuel emitted and less harm to the environment.
Generally, there is a not much difference in wear and tear on the engine, under normal usage, between the two fuels.

.  +1.
.  I've heard (but can't seem to locate any web pages to verify) that because the LPG burns slower and cleaner than gasoline, motors will last longer. YMMV

PS to OP: Since most of the fuel system is replaced when using LPG, I don't see where "hoses and seals drying out" would be a problem.

Agreed. without pressurized injection, you can't get as many joules of chemical energy into the cylinder because as a gas it is less dense and the fuel-air mix has less overall power than gasoline, BUT, being a gas already mixed with air its much better at combusting than misted liquid fuel. Less other chemicals also, its 'just' C3H8 and air, instead of all the stuff that makes up petroleum distillate (gasoline).

Back during the 1975 gas crisis, my brother converted his ford truck to run on propane. It worked fine but he didn't save any money. Propane was slightly cheaper at the time, but he got fewer miles per gallon. so it was an even swap. After the oil crisis was over, he got tired of hauling the big propane tank on his truck so he went back to regular gas. It costed him several hundred dollars to do the conversion. That's all i remember about it.