To me those number you quote seem ridiculous. I was partt owner and ran a propane distrinution company for a while and the conversion process for all of our trucks and automobiles was simple and cheap and took less then an hour. I am certain that it is nor more complicated or expensive to convert to NG. I think the parts were about $200.00. The real cost is the tank, however, when we converted our trucks we just put the tank in the bed.
Yea welcome to Calif.
http://www.greencar.com/articles/can-convert-natural-gas.php
The cost to convert to CNG can range from about $12,500 to $22,500 depending on the vehicle, engine, size of CNG tanks needed, and who does the converting. The greatest expense is for the CNG tanks, and the more capacity and number of tanks, the more expensive the conversion. While this may be daunting for many consumers, fleet users - like taxi companies and delivery services - can often justify the expense because of the fuel savings amortized over many miles. The FuelMaker 'Q' refueling appliance costs just under $10,000 plus installation and the Phill is priced at about $4500 plus installation.
