I owned an LPG-fueled car and it was really no different than gas-fueled one, other than more frequent need for refuel (I had a small tank installed where the spare tire used to be, and it only had around 100 miles of range).
In the 90's (!) much of the taxi fleet (and a good number of trucks) in Moscow, Russia was powered by CNG. Everything worked fine, in spite of a much lower level of technological advancement. If gasoline were to permanently go to $6+/gal, and the industry was deregulated a little, you'd see CNG retrofits that cost sub $1K and last for the lifetime of the car in basically no time at all. All the tech has been in place for decades, it's just a matter of demand now.
> tanks are supposed to be inspected every 3 years, and they expire 20-30 years after manufacture (and the tanks may have been manufactured much earlier than your vehicle). Some fuel stations (notably, PG&E's) require proof of recent inspection. And, replacing the tanks when they expire isn't economically feasible, leaving you with a lump of coal.
wouldn't all of these problems be addressed more adequately by a larger potential customer base & supporting infrastructure? (e.g. annual car inspection==tank inspection, cost decreasing due to bigger market, etc)
broader point still stands I think - if this was required of everyone every year, a secondary market like propane tanks for backyard grills, etc would probably emerge or it would be part of mfg warranties.
side note: no, I don't think market solves everything.
Non-obviously, only about half of the price of filling up is for the natural gas, the other half is electricity cost to compress it to pressures way beyond the pipeline pressure. This makes home based filling impractical, and CNG filling stations are fairly sparse.
Source: In 2017, I _really_ wanted to get a CNG Crown Vic/Town Car for HOV access, part of which was planning for a purchase in Los Angeles and driving to the Bay Area, refueling on the way; with the limited range, and without access to PG&E stations, I'd need to go up the coast, because I wouldn't make it on the 5.