natural gas

i remember a few years ago in the diesel power challenge i read of a duramax making close to 800 hp and getting almost 40 mpg running a natural gas injection system has anyone heard of or done this? if i can make my 24 valve get 400 mpg id be a very happy camper, haha

Here's the most recent thread with some info. Just be careful what you believe when people are posting up "unbelievable" fuel mileage numbers.

http://www.competitiondiesel.com/forums/showthread.php?t=164022

people seem to overlook the amount of natural gas, methanol, etc. they burn when they calculate fuel mileage

12v power !!!! said:

getting almost 40 mpg running a natural gas injection system

Click to expand...

Thats with natural gas supplementing diesel. Actual total economy is significantly less than diesel alone because methane is both less dense and less efficient burning in engines than diesel. Ditto with W/M injection and LPG.

That's 40 DIESEL mpgs. Did they say how much gas they burned?

I could see it -maybe- being cheaper since youre supplementing with a non-taxed fuel.
Look at the BTU content versus price on diesel then propane and natural gas. Also consider that natural gas needs to be compressed to very high pressure for max density versus propane which liquefies at a lower pressure (but needs heating when its depressurized). Not 100% sure if its ok if its legally considered a power additive or a road fuel by the revenue folks. Maybe?
It burns cleaner... not really a big deal with a common rail theyre pretty clean already.
If its going into the intake plenum at just the right amount it may burn before the injection event and cause pre-detonation.