LPG / Autogas T-DI

[Overfill]

Any reason there is a lack of interest in the states for Autogas? It seems like it would go well with turbocharged direct injection given the octane advantage (and lack of fuel entrainment.) I'd be surprised if it was simply storage qualms.. May be at the top of my pie-in-the-sky wishlist.

 

[JohnnyJohnson]

LPG has lower octane than gas.

 

[skyactiv]

I'm not a fan of it. I remember seeing it in Poland. Start the video at 1:02. 2:25 shows oil in the gas station and is rated T for thick. Need go fullscreen to make out viscosites.

 

[Overfill]

LPG has lower octane than gas.

You sure about that?

 

[daniel327]

LPG has lower octane than gas.

No, it doesn't. It does have a lower energy density though.

 

[JohnnyJohnson]

No, it doesn't. It does have a lower energy density though.

Yes roughly 10%

 

[Danno]

Used to run LPG on our fleet of delivery trucks in the 80's. Less power than gasoline, would burn valves, annoying to fill. Poor range with some pretty massive tanks strapped on the trucks. It was hard to find knowledgeable garages that could service the system.
It would also freeze in cold weather going through the convertor, liquid to gas. I wrapped a battery blanket around mine on overnight -25F nights to ensure a start in the morning.
Funny story. We had a driver meeting and a driver piped up with his solution. He used a soldering propane torch to thaw out the convertor most mornings. The meeting stopped, and we all said, you do what? Just NO! and STOP! before you blow yourself up.
That was the end of that fuelling system. We converted back to gasoline as truck replacements made it to the field.

 

[Overfill]

I'm not a fan of it.

Why's that?

Used to run LPG on our fleet of delivery trucks in the 80's. Less power than gasoline, would burn valves, annoying to fill. Poor range with some pretty massive tanks strapped on the trucks. It was hard to find knowledgeable garages that could service the system.
It would also freeze in cold weather going through the convertor, liquid to gas. I wrapped a battery blanket around mine on overnight -25F nights to ensure a start in the morning.
Funny story. We had a driver meeting and a driver piped up with his solution. He used a soldering propane torch to thaw out the convertor most mornings. The meeting stopped, and we all said, you do what? Just NO! and STOP! before you blow yourself up.
That was the end of that fuelling system. We converted back to gasoline as truck replacements made it to the field.

Yeah the dependency on vapor fueling is something I could see as problematic in cold weather-- must've been frustrating... That's why I like the idea of leveraging liquid DI and it's high fuel line pressure. Unless LPG was really cheap, the only advantage without high boost is the clean burn alone.

 

[DemoFly]

Economics, storage, hazmat classification. LPG is comprised of byproducts of natural gas and petroleum refining. It is only economically feasible as an alternative fuel.

 

[Number_35]

In the early 1980s the feds here pushed LPG as a gasoline alternative, even offering significant rebates on a conversion. It was touted as having all of the advantages of propane (cheaper than gasoline, and much cleaner-burning, so good for both air quality and engine life) without any of the disadvantages (propane was unsafe due to being heavier than air, and contained less energy per unit volume).

It never really caught on though, particularly here with our cold winters.

 

[michaelluscher]

LPG was never big in my area
Kinda like Propane and Methanol, it never really took off

CNG was marginally more successful in my area
I work for the local (natural) gas company, and even we're pivoting away from it
CNG Civic was no fun, sad VTEC noises

 

[BMWTurboDzl]

Any reason there is a lack of interest in the states for Autogas? It seems like it would go well with turbocharged direct injection given the octane advantage (and lack of fuel entrainment.) I'd be surprised if it was simply storage qualms.. May be at the top of my pie-in-the-sky wishlist.

You gotta hack the body to fit the tanks.

Exhibit A.

 

[Overfill]

https://patentimages.storage.googleapis.com/ff/34/08/04f82ed841dfec/US20170030299A1.pdf

One of the problems in the technology of gasoline direct injection is the formation of particles during combustion. These particles come from fuel droplets that have not been completely evaporated when combustion occurs.0004. In order to avoid this problem, it is necessary to optimize the injection timing for lowest particle emissions which represents usually not the optimum in efficiency, thereby losing part of the attractiveness of direct injection. Also, with gasoline as fuel, a very high fuel injection pressure (up to 250 bar in modern systems) is needed to produce small droplets and to enable this way sufficient primary mixture formation. Although an optimization of the gasoline direct injection parameters (pressure and timing)can reduce particle formation, it cannot be fully avoided, which makes it challenging to meet future emission legislation limits, especially with Small downsized engines in big vehicles and therefore high loads. In particular, in cold startand during warm up conditions particle emissions withgasoline are a problem to comply with future emissionstandards. In light of this, the introduction of a particle filtermight be necessary.

[on to the lpg injection system:] Alternatively, if the engine reaches its maximum combustion pressure or knocking combustion condition, ignition timing for LPG may be retarded similar to gasoline operation. Nevertheless the resulting ignition timing can be kept some degrees crank angle earlier compared to gasoline, preferably between 5 to 8 crank angle degrees earlier, and so at significantly better engine efficiency at high loads. Based on the natural characteristics of LPG (high octane number), it is possible to operate the spark plug throughout a significantly bigger area of operating points of the engine without incurring in abnormal combustion (knocking) despite the use of optimal settings to minimize fuel consumption and without the need to enrich the air/fuel mixture for component protection. This enables a minimization of fuel usage, particularly in the range of high loads where engines are more prone to knocking.