a few beginner questions

[bob.loblaw]

Hello all,

I am happy to have come across this site as I am close to being ready to purchase a used CNG (bi-fuel) vehicle but still have some lingering questions. Perhaps someone can help with my questions:

1. How long does it take to refuel? Of course I know tank size is a factor but just for example, how long would it take to refuel a factory bi-fuel ford f-150 (which is a 12 or 15 gal cng tank, I think)?
2. Pressure. Can you refuel a 3000 psi tank at a 3600 psi station?
3. Tank expiration. I know the tanks have an expiration date - is this enforced somehow in the inspection process in Utah?
4. Annual inspections and emissions. Is it any different for a cng vehicle in Utah (SL county)?
5. Is it more difficult to start an engine on cng, especially in cold weather?

Thanks!
Bob

[John Mitton]

Hello Bob, and welcome to CNGchat!

1. How long does it take to refuel? Of course I know tank size is a factor but just for example, how long would it take to refuel a factory bi-fuel ford f-150 (which is a 12 or 15 gal cng tank, I think)?

You will be able to fast-fill the F-150 from bone-dry in about three or four minutes. Fast-fill stations compress huge storage tanks to 3000 or 3600 psi (you will see them alongside the compressors when you visit a station). Once you open the valve on the pump nozzle to your vehicle, the higher pressure at the station rushes into your lower pressure tank and quickly equializes -- while, of course, the pump meters what is flowing past it.

If you install a home vehicle refueling appliance ("VRA") the process is different. A VRA has no storage tank so it slowly compresses the natural gas into your vehicle tank. The rate varies from one gasoline gallon equivalent ("GGE") per hour for the Fuelmaker FM2 and FM4 down to half a GGE per hour if you install the in-garage Fuelmaker Phill appliance. Check out the Photo Gallery and Home Refueling forums for details.

2. Pressure. Can you refuel a 3000 psi tank at a 3600 psi station?

No. But a 3600psi vehicle can fill anywhere.

Vehicles with 3000 psi tanks have a larger diameter connection stem than those with 3600 psi tanks. Fueling hoses dispensing 3600 psi have the smaller diameter connector to ensure they cannot connect to a 3000 psi vehicle. Conversely, this provides that larger diameter 3000 psi hoses can connect to all vehicles.

There is much debate if all of this really matters, since 3000 psi tanks are engineered to handle much higher pressures, and some people have been known to shave down the vehicle's connector stem to go ahead and connect to the 3600 fueling systems (note that we do NOT condone this!).

In California, Nevada, Arizona, most pumps have two hoses - on one side you can fill at 3000 while on the other you can fill at 3600.

In Utah, Questar splits the baby down the middle by dispensing 3300 psi with the larger diameter 3000 psi hoses, thus any vehicle can fuel from any hose no matter what pressure the vehicle tanks are rated for.

3. Tank expiration. I know the tanks have an expiration date - is this enforced somehow in the inspection process in Utah?

Another hotly debated topic. It is my understanding that the USA is the only country in the world to put expiration dates on CNG tanks (I suppose this might have something to do with our penchant for litigation), but I digress... I would be surprised if your typical quick-lube shop would even know to look at tank expiration when you do your annual safety inspection. I do know, however, that most alternative fuel conversion shops make it a point to check tank expiration dates and will remove and destroy any old ones they encounter.

4. Annual inspections and emissions. Is it any different for a cng vehicle in Utah (SL county)?

It is the same, excepting if you have a bi-fuel vehicle the emissions must pass using both fuel sources.

5. Is it more difficult to start an engine on cng, especially in cold weather?

Yes. My Civic GX takes a few extra cranks when it gets cold, and the manual warns that at -5F it might not start at all. Since I have it in a garage I am not too worried. Perhaps others can chime in on their experiences?

[annam]

Re: a few beginner questions

You don't happen to be a fellow Arrested Development fan?!

I LOVE My CNG Civic, I bought it 3-4 weeks ago and so far I have not once regretted it. It fills just as fast as it would at a regular gas station, but its way cheaper. The only downside is since its not bi-fuel I have to watch my gas and plan when to fill. Also, the different psi fills really make a difference on how far I can drive, especially since I do mostly city driving. But, I drove from SLC to Lehi then Provo and back (130 miles) and filled (even though I had a 1/2 tank left, I was curious) for $2.50! way cheaper than my gasoline civic which would have cost $10-15!

[mostlyharmless22]

a few beginner questions

We've had our 2001 Cavalier for about 6 months. Best purchase we ever made! We get about 25 mpg and an equivalent gallon of CNG is about 95 cents here. The only issue is getting a good fill. It's a 5.9 gallon tank but a really good fill at our 3000-3200psi ONG Service Center is only about 4.3 gallons. We still get about 125 miles but I would love to have it really full just once. We may get a FMQ36 some time next year, if we can find a good price. Since I found a listing of all the conversion kits available and for which models, I am hoping to eventually find a converted Astro van.

[Royger]

Re: a few beginner questions

HELP, I'm a newbe...Looking at a natural gas vehicle. I'm wondering if 1 gallon of natural gas is measured the same a 1 gallon of unleaded gas? Does natural gas improve your gas milage or decrease it? If a natural gas system goes out where do you go for parts and are they expensive? Thanks guys.

[bob.loblaw]

Re: a few beginner questions

to annam - arrested development - cracks me up - too bad it was cancelled.

to all - thanks for your replies. I've pretty much decided to buy a bi-fuel pickup - just have to sell my diesel first.

The pressure issue concerns me. If CNG is ever going to be a viable alternative this will have to be resolved. For now, since I'm in Utah, I'll just have to make sure the vehicle I buy has the 3000psi connector.

Thanks!

[John Mitton]

Re: a few beginner questions

Bob: The Questar pumps all have the wider hose connector so they fit on both 3000 and 3600 psi vehicles. So buy whatever you find is best for you without worrying about refueling pressure.

Royger: Welcome to CNGchat!
Natural gas for vehicles is dispensed as a compressed gas, not liquid. So as with other alternative fuels, it is measured in Gasoline Gallon Equivalents. There is a document in the Downloads section of this web site under Various Documents that provides some detail on how this is measured (you may need to log in to the left side bar to get to the Downloads).

Natural gas is also 130 octane, so most find that their gas mileage is at least as good as with gasoline, with pretty good pep to the drive too.

As for getting service for your natural gas vehicle, when it comes to anything outside of the fueling system and engine you can take the vehicle anywhere you would normally take a gasoline model (transmission, brakes, shocks, exhaust/mufflers, tires, etc.). For the natural gas specific service check out the list of shops in the CNG Service & Conversions forum on this site.

Fixing the CNG system depends on the vehicle, nature of the problem, etc. I understand the Ford Contour CNG is quite expensive to fix... might want to steer clear of that model. Some of the older model Chev. Cavalier CNG/bi-fuel can sometimes require a $1,000+ master valve job -- if you get one of these try for a newer one such as 2002 to 2004.

[Curtis]

Re: a few beginner questions

HELP, I'm a newbe...Looking at a natural gas vehicle. I'm wondering if 1 gallon of natural gas is measured the same a 1 gallon of unleaded gas? Does natural gas improve your gas milage or decrease it? If a natural gas system goes out where do you go for parts and are they expensive? Thanks guys.

All fuels have a Gasoline Gallon Equivelent, even electricity. What they measure is the energy content of each fuel. When there is the same energy content as 1 gallon of gasoline, you have an equivelent gallon. Energy can be measured a number of ways; British Thermal Units (BTU's), Therms (1.25 therms = 1 gge, although this too can vary slightly, depending on the quality of the methane in use), and so on.

Your gas mileage will be virtually the same with CNG. You are running a much higher octane fuel (130 octane). Seems like you should make more power, right? Well, actually the natural gas displaces the air (your fuel oxidizer) and you normally have only a very slight reduction in power over a conventionally powered version.

As for repairs, there are a number of places that repair CNG vehicles. Anyplace listed in the files section of this site that does conversions, and any dealership that is certified to sell and service ngv's. My Honda dealership is negotiating with the GSA to service their cng fleet. That means that there are Chevy, Ford and Honda dealerships that can work on your car. As for costs of repair... It's like the rest of the car, there are some inexpensive parts, and there are some expensive parts. Some of the more expensive items can be purchased aftermarket at a substantial savings. It's the same as any car you've ever had...
only different.

[Curtis]

Re: a few beginner questions

to annam - arrested development - cracks me up - too bad it was cancelled.

to all - thanks for your replies. I've pretty much decided to buy a bi-fuel pickup - just have to sell my diesel first.

The pressure issue concerns me. If CNG is ever going to be a viable alternative this will have to be resolved. For now, since I'm in Utah, I'll just have to make sure the vehicle I buy has the 3000psi connector.

Thanks!

You'll find that 3600 psi is the standard for all vehicles produced after 2002. Ford used the 3000 psi for a number of years but adopted the new standard as of 2003. You are much better off finding a post '02 vehicle. When I put my station in, I didn't even bother putting in a 3000 psi side. It would have been another $50,000 so that I could fuel only a handful of cars... it wasn't worth it.

[utahisc]

Re: a few beginner questions

How much smaller is the 3600 psi connector than the 3000 connector and can you replace the 3000 connector with the 3600 lb connector?(if questar-utah is filling at 3300 lbs already on the 3000 lb systems- how dangerous is 300 additional lbs?
Thanks in advance

[Highmarker]

Re: a few beginner questions

How much smaller is the 3600 psi connector than the 3000 connector and can you replace the 3000 connector with the 3600 lb connector?(if questar-utah is filling at 3300 lbs already on the 3000 lb systems- how dangerous is 300 additional lbs?
Thanks in advance

One thing you have to know about these tanks is that these tanks are rated for 3,600 psi (or 3,000 psi - depending on the tank) at 70°F. Temperature has an effect on the pressure, as I sure you notice you get more GGEs in the winter than in the summer. NGV2 tank specification states that the maximum pressure a container may be filled to can not exceed 1.25 times the nominal service pressure (3,600 or 3,000) immediately after filling, regardless of temperature. This says that you can fill a 3,600 psi tank up to 4,500 psi and a 3,000 psi tank up to 3,750 psi.

[John Mitton]

Re: a few beginner questions

Just be careful not to slow-fill a 3000 psi system to 3600 psi on a regular basis. Fast-filling at the public stations to 3600 psi is probably no risk, as once the tank cools down after the fill you are back to a lower pressure.

[gregmd]

Re: a few beginner questions

I picked up my new Black Civic GX from Curtis yesterday out in Palmdale (I live in Utah). Curtis gave me a good fill and I took posession of the car in Primm. Made it all the way home topping it off along the way. Last top off was in Orem and total cost was $8.00!! At the station in Fillmore Utah it was weird because I started to refill it and she did not reset the pump until I was almost done. I tried to be honest and give her more than the $1.30 she was asking for and she refused!

Thanks for your help Curtis!
This was definately the right move.
p.s. Give you finance manager my love!

[gregmd]

Re: a few beginner questions

P.S. total trip was 476 miles!

[daysailor]

Re: a few beginner questions

We've had our 2001 Cavalier for about 6 months. Best purchase we ever made! We get about 25 mpg and an equivalent gallon of CNG is about 95 cents here. The only issue is getting a good fill. It's a 5.9 gallon tank but a really good fill at our 3000-3200psi ONG Service Center is only about 4.3 gallons. We still get about 125 miles but I would love to have it really full just once. We may get a FMQ36 some time next year, if we can find a good price. Since I found a listing of all the conversion kits available and for which models, I am hoping to eventually find a converted Astro van.

i have been looking for conversion kits and cant seem to find any. where did u find them. i want to convert my 94 accord to cng and my 83 nisson diesel. thanks for any info. al