Anyone tried LNG or CNG in a BMW yet?

[DKJimmy]

My father runs an indy shop in jax beach and he's currently waiting on a terroidal propane tank to put in the spare tire well of an e36 318i, he's got all the engine internals sorted out, and I'm pretty excited to see it running on clean fuel.

Anyone else done something like this on the forums?

[jc43089]

This would be cool to see, I plan to convert my Toyota LandCruiser to CNG at some point to make it more economical to drive.

[LebanonBavarian]

Problem is it won't make the same power as gas

[Cheeseburger]

I've got a Suzuki Sierra/Samurai which runs straight LPG/propane... it's an absolutely fantastic fuel with very few downsides.

The power curve is slightly different to regular petrol/gasoline; it's got FAR more low-down torque than a regular petrol engine, and maybe doesn't throw down as much top end power, but that's never proven to be a limitation in the Samurai which has a very revvy engine. Also, my fuel consumption is 1:1 as i've had the engine rebuilt to specifically run straight LPG. I'm only using an 8-valve motor design too, which theoretically aids the torque throwdown. And the engine should last MUCH longer due to the fact it's a dry fuel with limited abrasive qualities. And I think I have two moving parts in the whole intake side which vastly simplifies any need for troubleshooting.

The only mods included a slight recurve of the distributor timing and a bump up of the compression, and spark plugs that are one heat range colder.

I think most people who complain about the performance quality of LPG do so because they've got it installed as a dual fuel setup in which a car is primarily designed to perform on petrol/gasoline. Each fuel has its own combustion characteristic, and unless you design an engine to specifically take advantage of a singular set of properties it'll always be a performance compromise. For example, you can't just throw diesel in a M3 and expect no difference in performance. The same is true when running a petrol engine on LPG - it's compromised performance.

I'd be all for trialling it in a BMW, but the problem is the price of LPG/CNG is rising, and engine conversion (at least in Australia) is of little benefit anymore. You've just gotta be in it for the sheer science of experimentation.