Worldwide, there were 14.8 million natural gas vehicles by 2011,

[island911]

per wikipedia Compressed natural gas - Wikipedia, the free encyclopedia

If you don't know about these, you should. The US just getting to massive reserves of this fuel.

it's an interesting read, IMO.

[porsche4life]

My folks have 2 pickups. They run awesome,cheap fuel, what's not to love?

[cashflyer]

And there's a CNG filling station on every corner!

[fastfredracing]

I don't know about filling stations, but around here, there is a drilling rig on nearly every corner.

[GH85Carrera]

There are at least 6 stations on this side of town within a few miles of my regular driving area. The biggest problem I still see is each station has just one CNG pump. If there is someone (or two) people in line to use it you just get to wait.

I know of at least one company working on an affordable home compressor unit. When that is available I might do a conversion. I just park in the garage like normal, hook up the compressor and forget it. It fills up the tank and turns off when the tank is full. I leave every morning with a full tank.

Right now the home compressor units are over 10 grand. When that is 2 grand or less it is a great deal.

[matt711]

All the cop cars where I grew up were running on LPG and that was 20 years ago.

[1990C4S]

Natural gas needs extremely high pressures to liquify. As a result the range is not good.

Propane is a much better option, NG would drive you crazy with refills.

[GH85Carrera]

Many of the cars I see running around on NG are dual fuel cars. They run fine on either fuel. Some are NG only and would never work for a road trip. My across the street neighbor had a dual fuel SUV. For all of his around town driving he always ran NG and when he drove up to Nebraska to visit relatives he would run to the end of the NG and switch to gasoline.

There are many Hondas that came from the factory as NG only cars. I know one guy that has one. He loves it for local driving. If he has to go see his parents in Arkansas he rents a gasoline car.

[onewhippedpuppy]

This is super common in the midwest, where natural gas is plentiful. Lots of stuff runs on either natural gas or propane. You guys on the coasts are just behind on the times.

[island911]

Originally Posted by 1990C4S

Natural gas needs extremely high pressures to liquify. As a result the range is not good.

Propane is a much better option, NG would drive you crazy with refills.

Yep. ...and yet CNG (not even liquified) has multitudes higher energy density than batteries. ...by both volume and weight. And better than even propane is octane. The question is, what will the relative cost be? ...will people be willing to fill up twice as often if the cost per mile is cut in half? (or whatever) Certainly people have been going crazy for the electrics (horrible range and fill-up that take forever)

refnc File:Energy density.svg - Wikipedia, the free encyclopedia (a really useful graph)

Isn't natural gas really dangerous and explosive?

[island911]

Only when it has a really good mix of oxygen.

[GH85Carrera]

Originally Posted by Mark Wilson

Isn't natural gas really dangerous and explosive?

You mean like sorta like gasoline?

[matt711]

Can a diesel be made to run on either propane or NG?

[john70t]

Originally Posted by matt711

All the cop cars where I grew up were running on LPG and that was 20 years ago.

I thought that was reserved for on-scene sargents, and light-duty duties.
(Perhaps dual-fuel certified?)

In our northern snow belt:
Police vehicles usually require extended idling, often in sub-zero conditions with heaters/engine going, and such, then always being able to engage in high speed pursuit at the drop of a hat.

[island911]

Originally Posted by matt711

Can a diesel be made to run on either propane or NG?

wrong flame speed (iirc) and no spark plugs in Diesels.

but htere's this (per wiki)

CNG use, either alone ('dedicated'), with a segregated gasoline system to extend range (dual fuel) or in conjunction with another fuel such as diesel (bi-fuel).

[john70t]

Originally Posted by matt711

Can a diesel be made to run on either propane or NG?

At this time, no.
(AFAIK)
Diesel engines require specific air/fuel compression to create an exact ignition temperature within the combustion chamber, and at the exact time.

There are innovative variable-valve, variable-compression, etc. designs that are 'out there', however, they'd probably require way too much uncertainty and engineering and manufacturing money to be of viable use to most companies.

[1990C4S]

Originally Posted by Mark Wilson

Isn't natural gas really dangerous and explosive?

Pretty sure that's required for a fuel. Otherwise we'd use water.

Ya'll got me good!

[1990C4S]

Originally Posted by matt711

Can a diesel be made to run on either propane or NG?

NG can be used on a Diesel the way nitrous oxide is used on gasoline engine.