What happened to Propane?

Propane used to be a popular conversion back in the 80's and 90's around here.

I also understand it is pretty much the same as 120 octane.

And I know there's pretty much zeros coming out the tailpipe.

So why has Propane fallen out of favour as a motor fuel?

I think it's probably due to the cost of converting a vehicle, roughly 6 to 12 grand from what I read and will get 5 to 10 percent less mpg then gasoline.

I swear propane is also a lower volumetric density than gasoline too.

https://www.lpgasmagazine.com/cummins-fuel-agnostic-engine-platforms-to-feature-propane/

There is some renewed interest for propane / natural gas in the medium and heavy duty world. There has always been a small fleet of natural gas vehicles for specific tasks / customers. With emissions and fuel supply factors there is a push for more options beyond gasoline and diesel. As always a lot of it comes down to fuel station infrastructure. Options are increasing for natural gas and maybe hydrogen in the future.

In reply to GhiaMonster :

Very heavy duty- there are quite a few new cruise ships powered with LNG. 

In my area a significant percentage of garbage trucks are powered by natural gas. 

We bought a ten year old Roush propane converted E350 as our shop tow/parts chaser rig. 

It's..... fine. It works like any other vehicle.  There is an unfamiliar 5 second delay when you turn the key before the starter cranks.  

If it wasn't for filling it, you wouldn't know. Filling it on the other hand isn't as easy as you'd think.  Most propane filling stations can't connect to it. There are 4 places in town that can do it and the one closest to our shop can't fill it past 3/4 tank. Because of this there is a bit of range anxiety and it never leaves town.

When we bought it 18 months ago it was about half the price of similar year, mileage, conventional fueled versions.  The propane bit scared a lot of folks off. 

Trying to get an idea of what the fuel availability actually looks like I came across this map from the .Gov.  You can select between different fuels and plot out routes.  Still a long way to go for any long haul action beyond diesel. Shorter routes can certainly make sense depending on your region.

https://afdc.energy.gov/fuels/natural_gas_locations.html#/find/nearest?fuel=LPG

It is an infrastructure issue.  The infrastructure was built to distribute gasoline.  There is little to no profit in building infrastructure.  

The company where I worked ran nearly all of their truck fleet on propane for many years.  Starting in the 80s, innovations like electronic fuel injection made new light-duty trucks more efficient, and at the same time increased the cost of a potential propane conversion, making it a lot harder to justify.  Meanwhile, on the medium/heavy trucks, International and others dropped their old gasoline engine offerings and committed to diesel, which provided much better fuel economy.  

School buses around here are often propane powered.

I think it's an infrastructure issue for the most part. That and things are so similar to gasoline. Similar range, similar performance, similar repair bills. It makes it unattractive for the individual. Most propane and natural gas conversions I have seen are fleet or limited use vehicles. Like Zamboni's are propane a lot. Maybe back in the day that was important for emissions but with the state of EFI I don't know that running a car in an arena for 13 minutes to resurface would matter. 
 

I converted this car to natural gas almost 30 years ago using take off parts from the local gas company. They had converted a lot of their fleet and took the parts off before they sold the trucks at auction. The difference between running on gas or natural gas was nearly transparent. It ran a little better on natural gas (cleaner by testing I think it had a little more power but that wasn't tested). 
Range anxiety was real there was one place within 60 miles to fill it up. This car was dual fuel so that was alright but it would have been a huge barrier. 

They converted the pickup trucks at work to propane, only refill station was 15 miles away and in the winter the propane shrunk down like, well, ever try to use your propane BBQ in the winter?

Everybody was converted back in less than a year.

In Atlantic City we have a large number of Short Buses called "jitneys" that travel across the island. Usually up and down Pacific Ave where most of the Casinos are, but also to the Train Station and to the Marina District where the other three Casinos are located.

They are all Natural Gas Powered.

The ACUA, the Atlantic County Utilities Authority, which collects out trash, supplies our water, and processes our sewer, has a couple of huge fields of solar panels and a refueling station for these and any other CNG powered Vehicles in the area.  Waste Management's garbage trucks also are CNG powered.

The taxi fleet in Ottawa used to be CNG. Now that I think about it, I haven't smelled CNG coming from a taxi in a long time. Obviously that wasn't an infrastructure issue as they had it solved for the regional taxi system.

Holland and Belgium had a lot of  Propane powered cars years ago , 

it was much cheaper to run than gasoline as there was less road tax , 

My buddy shipped a full size Dodge conversion van to Holland and had it converted to Gasoline/ propane , 

It ran fine on Propane with only a little power lose.

I seem to recall the offroad guys running propane years ago because it would work at extreme angles where a carb would not. But with EFI that seems to be no longer an issue.

They converted a Land Rover or Range Rover to propane on Wheeler Dealers.

Seems like if you had a limitless source of free propane, ran in moderate climates only, and only travelled less than 1/3 of a tank away from your home base, it would be a decent option.  

Cousin_Eddie (Forum Supporter) said:

In my area a significant percentage of garbage trucks are powered by natural gas. 

Now if you could come up with a way to power it off the rotting garbage in real time you'd be bringing the awesome.  And then instead of dumping the load you could just decompose it by driving the truck around.  

Mothers built a Chevelle with a gnarly blown 454 LSX on propane. They said it took absolutely massive injectors to feed it. They also said that the oil they drained out after 3000 miles was as clean as it was when it went in and that the rocker panels above the exhaust were always clean.

I considered it years ago, and even though I would have been able to do the conversion myself with mostly free parts, between the fuel cost, power loss, and inconvenience, I just couldn't make a case for it.

When I worked in the composite industry in the 80's, I worked for the R&D division, and we spent a lot of time filament winding large aluminum tanks to convert highway trucks and buses to CNG. If I recall the buses happened but the highway trucks didn't.

I went to an SAE convention a few years back on the topic of LPG/CNG fueled vehicles.  Most of the presentations were the distribution folks talking about all the cool distribution plans they had that were waiting for OEMs to build vehicles and the OEMs talking about all the cool vehicles they had ready to go when there was a distribution system.  There's also no consensus about whether LPG or CNG should be adopted there are pros and cons to each.

In reply to APEowner :

There ya go.  No one wants to build the infrastructure.  While there are issues, LNG, CNG, and propane offer way low emissions and lower costs.  The notes above about low oil contamination and lack of soot are also true.  The US has enough NG to do this a long time until innovation can arrive at better solutions too.  It didn't materialize in the past over infrastructure costs and who would pay for them.  

LNG is cryogenic.  The fuel tank needs to be insulated to keep it from boiling off and even with that you still need to vent it.  Apparently it's not recommended to park one indoors due to explosion hazards.  Also, natural gas is mostly methane which has a very strong effect as a greenhouse gas (far more so than CO2), so intentionally venting it seems counter-productive.

CNG is compressed at room temperature, but the density is a lot lower so you can't fit anywhere close to as much range in the same volume as the fuel tank. 

Propane liquifies at room temperature under pressure so avoids the venting problem and has almost as much range per unit volume (it's got lower energy density so you lose about 10%).  The big issue with converting vehicles is that gas tanks don't have many constraints on their shapes, so they are usually designed to fit around other components in the vehicle.  That's a lot harder to do with pressurized storage, so you can't use the existing fuel tank space very efficiently.  So either you lose a lot of range or you fill the cargo space of the vehicle with propane tanks.  That's may be OK for a pickup in light duty corporate fleet use, but it kills the potential for cars.

So it's not JUST infrastructure.  Gasoline and diesel got to where they are because they're the most convenient and practical way to store and handle fuel for an internal combustion engine.