Feedback from Compressed Natural Gas or Propane Vehicle Users

After getting the optimum adjustments on a Ford F100 pic-up I got 22miles per gallon. [Factory settings gave 18mpg]

A propane feul system was fitted and money-wise there was absolutely no differance.

jurie sa, that doesn't sound too good at all.

And this is the concept that T Boone Pickens wants us all to sign up to?

I don't think so.

I can only speak for Germany, not for anwhere else, but Auto Gas is about half the price of Super.......so even if the MPG is the same (I hear its actually usually slightly worse), then price wise and cleanliness wise its still much better....

I have done some research into conversions for my own use and find the offerings pretty slim. It looks like Honda is the only manufacturer that actually produces for the public in the form of a Civic sold only in California. The GSA will auction bi-fuel and dedicated LPG trucks and some cars occasionally. I don't know if Average Joe can buy or order these vehicles new from a dealer.

For a conversion to be really cost effective it seems like the real recovery would come from the gasoline price v LPG price per mile driven. I don't want to discount the reported savings in wear and tear but the cost of a set of spark plugs and an oil change really don't sway me over. The same reason I bought my V-10 vs diesel sure I have a trailer and I tow it around on vacation but I could never drive it enough to offset the initial cost of the power-stroke in fuel savings alone.

I'll give Pickens this much it we are going to spend $5.00+ a gallon for transportation fuel I would rather have it all spent inside our own border than line the pockets of fanatics, dictators, and terrorist.

I knew a lot of people who converted vans or pick-up trucks to propane and they were quite satisfied. I considered it but I had a problem finding a place that would do a dual fuel conversion. Up here it can hit -40C (which is the same as -40F) at this temperature propane can be hard to start. At the time the cost of the conversion plus the propane tanks was well over $1,000. They would quote a price for a propane conversion that retained the ability to use regular gasoline when required or when you couldn't find a service station that dispensed propane, but they wouldn't perform the dual fuel conversion..

There were anecdotal stories of people who filled their cars in the southern US where the fuel was not propane but butane which apparently has poorer cold weather starting performance.

You can get propane kits for diesel engines. The still require some diesel fuel for ignition but the inject vapourized propane into the air intake. When natural gas came to the small city where I grew up the HUGE diesel engines in the power plant were converted to inject natural gas into the air intake and enough diesel was injected into the cylinders to get ignition. I have heard of a similar trick being used on LNG tankers, the boil-off from the LNG tanks is fed into the air intakes for the diesels.

I was in Vancouver British Columbia once and the Taxi was using compressed natural gas. The driver had nothing nice to say about it, the car was quite obviously gutless. Whether this is typical of CNG or just the particular installation and engine tuning, I could not say. The taxi driver said that there was intense competition among the drivers to get assigned a regular gas or propane car because they performed so much better.

Thanks for the reply! I will be installing a CNG conversion system in my Chevy Truck in two weeks and look forward to reporting the progress. Because there are not many CNG fueling stations in my area I will be trying Propane first and then later switching to CNG after a local filling station is operational. The system that I am installing has the ability to operate on the original fuel or the alternative fuel at the push of a button and assures no loss in power or performance. I will gladly share the results with everyone.

Natural gas here in Brazil is being used successfully by people that have high distances travelled day by day and taxi drivers. Indeed, some problems occur and all can be attributed to poor engine conditions, bad adjustment and home made adapt kits... some smart guys still insist in adapting a domestic kitchen LPG cylinder to a car that has been installed a CNG kit and going to a refueling station and... well, they are luck all the safety protocol around here is mandatory about keeping no people around the car. They are a little expensive. Around here, you should drive more than 60 km per day so the kit can pay for itself in a reasonable time. And you must install it in a reasonably new car, because its installation in an older, lower priced car makes no sense at all. In some states, you have a significant discount in car anual property fee, what really makes difference in the payback time. Unfortunately, this is not my case... Regarding problems, starting the engine is always done with gasoline. Change is automatically accomplished after start if there's enough CNG in the reservoir. The car may be fuelled by the original fuel (currently most of cars use methanol or gasoline mixed in any proportion). Some tricks include to keep your air filter always new, replaced in a hard time regimen and not controlled by engine performance, or even installing a competition type high flow one. This because the gas is injected in the intake manifold and, if any back pressure or reverse flow is sensed in the engine feeding, detonation in the intake duct may occur with damage to the inlet air path hardware.

I converted a 1985 GMC 1 ton cube van to propane in 1989 and ran it to 2004. The conversion paid for itself the first year when propane prices were 8.3 cents per litre and gasoline was 44 cents per liter. Efficiency in fuel cosumption was 60% of gasoline on a volume basis. It would not start below -20C. Acceleration was poor. I did not regret conversion for 13 years until the price gap between propane and gasoline narrowed.

Don

CNG does not produce as much power as propane. As an example. A 15KW generator is only rated at 13KW on CNG. Take that into consideration when doing your comparisons.

I voted for this as a good thread.

I had two reasons.

One I hadn't much thought about it as an option.

Two I learned a good deal.

3) it's a small step to biogas....[we have to stop for burritos or we'll never make it home!]

the new avatar makes you look like Larry King [suspenders] minus the heart attacks & wives

Thank you for the informative response. The system I will be installing on my truck has its own computer ECU that works in place of the OEM ECU when running on aternate fuel. I will know very soon how well it works as the manufacturer states there is no power loss and the system self adjusts on the fly. I have also heard that not all propane is he same quality, we have one dealer in our area I will not seek propane from. Are you a certified mechanic or just one who does his one work/repairs? I would like to hear more about the system you have used.

Thanks,

Randy

filkinsr@ajsresearch.com

I am just a self taught lover of all things mechanical and electrical. Everything I have done for myself and others is custom designed and set up per their vehicles needs.

I have a load of NOS high output vapor carburetors and vaporizers that were designed for the big block high horsepower engines that were used in the RVs back in the 1980's. They work great on the 400 Plus Cubic inch engines! The smaller sized vehicles get the Impco units from eBay that best match their size.

My old 1974 Ford with the 390 engine used the RV system and so does the built up 460. The V10 has an Impco 425 unit set up between the air filter box and the throttle body. All the systems I set up have an on the go switchover capability that uses a simple dash mounted switch to do the fuel change over. Its as user friendly as I can get.

I have also used the Impco 300 type carburetors on the mid 1990's Chevy 350 engines with the throttle body injection system with good over all results. My moms Husband has one and loves it! Especially when propane was $1.40 a gallon while gas was near $4.00 a gallon not to long ago!

I also have done service work on propane powered forklifts and assorted machinery as well as a few older propane vehicles for others. Once you know the basics of how they work and how they are sized its really an easy system to work with regardless of what type of vehicle or machine its on.

As far as the internals of the engine being converted... I would suggest hardening the valves. Add a larger radiator (because you can never have a radiator that's too large)... Maybe a high output ignition with hotter, slick orange or blue plug wires and better plugs.

JL Mealer
Mealer Companies LLC
http://mealercompanies.com