Just bought my first CNG vehicle and need some advice

[David Burklin]

I won an auction on eBay for an F150 factory bifuel. I think I got a fair deal on it, considering what I've seen CNG vehicles doing over the last month. The truck has the standard 12gge tank. Anyway, I fly out to Phoenix in early July to take delivery.

We are planning to make a vacation trip out of the pickup, with a jump over to Disney, Vegas, Grand Canyon, and then back home to Oklahoma. I have some questions that have come to mind.

1. I would assume at some point driving across to Cali, I'm going to run out of CNG and have to make part of the leg on gasoline. When I'm on CNG, will the gas gauge indicate actual tank capacity, or is there another gauge somewhere? Or what is the indication of low fuel? Once it does run out, do I just flip the on dash switch while in motion, or can the switch only be made while the vehicle is off?

2. I would assume that as the PSI in the tank declines, I will reach a point where there isn't sufficient pressure in the tank, before I'm actually out of gas. At what PSI does this occur? Is there a performance degradation at this point? Does this mean that even though I've got 12GGE, I actually don't have 12 gallons range, or is the low pressure taken into account so that 12 GGE is the effective capacity of the tank?

3. Any other pointers, suggestions, or other for a newbie? The guy I'm buying the truck from is just re-selling it, so I don't expect a lot of instructional value added from him.

[CNGfamily]

Re: Just bought my first CNG vehicle and need some advice

1. I would assume at some point driving across to Cali, I'm going to run out of CNG and have to make part of the leg on gasoline. When I'm on CNG, will the gas gauge indicate actual tank capacity, or is there another gauge somewhere? Or what is the indication of low fuel? Once it does run out, do I just flip the on dash switch while in motion, or can the switch only be made while the vehicle is off?

The F150 uses the same gauge for both fuels. There's a switch on the dash to the left of the steering wheel that sets your fuel useage to gas or CNG. the switch position set before you start the car is what you'll get (as long as everything is working and you have fuel). The fuel selected is shown on the gauge. When your run out of CNG, the vehicle will switchover to gasoline while you drive. You cannot force a switchover from on fuel to the other while the engine is running (except by running low on CNG)

2. I would assume that as the PSI in the tank declines, I will reach a point where there isn't sufficient pressure in the tank, before I'm actually out of gas. At what PSI does this occur?

No way to tell on a stock bi-fuel. I've had two other coverted vehicles that also include an analog gauge somewhere on the vehicle (neither case was readable while driving). The switchover depends upon the system and the sensors... I'm guessing the best you could hope for would be something that would switchover somewhere around 200 PSI.

Good luck and enjoy your vacation!

[cngbuck]

Re: Just bought my first CNG vehicle and need some advice

Factory bi-fuel systems have a seloctor toggle switch that when CNG or GFI ALT is selected and burning green means you are running on CNG. When you have a full tank of CNG the gas gauge for gasoline is the same for CNG. When it runs low it will display a low fuel check gauges light when the needle approaches empty. Just keep driving until you feel a slight bump, that means you have just automatically switched back to Gasoline. Leave the switch where it is, and when you fuel back up with CNG it will be ready to go for you.

[David Burklin]

Re: Just bought my first CNG vehicle and need some advice

Thanks for the responses. Good information. The auto-switching thing is really good to know. I'm really excited to get it.

[Bender]

Re: Just bought my first CNG vehicle and need some advice

Does this mean that even though I've got 12GGE, I actually don't have 12 gallons range, or is the low pressure taken into account so that 12 GGE is the effective capacity of the tank?

There are lots of factors affecting how many gallons you can get in your 12 gallon tank. With my F-150 bi-fuel I typically get around a 10 gallon fill if I run the tank completely out before filling. I average around 150 miles per tank doing city driving and 180 on a good fill on the highway (at 75+mph). Rarely I'll get over 11 gallons in. Though once I actually got 13, go figure.

Good luck with your purchase.

[maxman]

Re: Just bought my first CNG vehicle and need some advice

Be sure you have fuel in both tanks. It switches automatically to gasoline from CNG. You'll get sort of a clunk/surge. However, it doesn't switch automatically from gasoline to CNG, so when you are running on CNG, make sure you have gasoline in the gasoline tank.

The Ford CNG service manual shows the 3600psi is dropped to 105psi by the regulator and switches to gasoline at 75psi. My sons 2 F150's and mine both switch over around 150-160 miles. When you fill the CNG tank, reset the trip odometer.
Also, when you fill the CNG tank, depending on the outside temperature, you should only expect about 10-12 gallon fill due to the temperature rise from compressing the gas. The last time I filled, I only got 10 gallons in the F150 tank and it had run out and switched over at 157 miles.
My son filled my tank on a hot day and I noticed it was only showing half full. The fuel gauge switches automatically with the fuel used. Don't be too surprised when you fill the CNG tank and it shows full. Then just a little later it might show a little as half a tank. The gauge measures pressure I think and after the CNG cools after filling, the pressure will drop from the cooling of the gas.
When you first get the truck, and first turn the key on, you should have the indicator light on the fuel change switch flash green at the time all the other warning lights flash before you start it. If it's out of CNG, it should still flash green at first, then go out. If it doesn't flash green right at first, your CNG system is probably not working. If it's in the CNG position and you have CNG, it'll stay green.

Good Luck
Max

Good Luck

[cng_john]

Re: Just bought my first CNG vehicle and need some advice

Since you are making a long trip, I would suggest that you also plan your fuel stops ahead of time, and if possible call the stations a couple of days in advance to see if their CNG pumps are operational.

I know this is not such a big deal since you have a bi-fuel vehicle, but it is nice to know what is actually working if you are driving out of your way at all, hoping to get CNG.

http://www.eere.energy.gov/afdc/stat...nd_station.php might help in locating stations. It helped me on a recent trip to So. Cal.

[David Burklin]

Re: Just bought my first CNG vehicle and need some advice

Thanks everyone. Some great information here for the novice.

The truck has a clean bill of heath from a ford "buyers inspection" that was performed early June, so I'm reasonably confident in the CNG system is in good order, but nice to know the tell-tale signs, and to know what to expect.

I have a good plan laid out with stations all along the way, expect for that danged-ol' desert run, where nothing exists except tumbleweeds and dust.

I'll be posting on the CNGPRICES site with current prices/etc once I return.

One last question that comes to mind, does anybody know what the capacity is on the conventional gas tank on the F150s?

[CNGfamily]

Re: Just bought my first CNG vehicle and need some advice

One last question that comes to mind, does anybody know what the capacity is on the conventional gas tank on the F150s?

I'm pretty sure that my daughter's 2000 F150 bi fuel has the large gas tank (30gal); I don't know whether or not all the long beds would have the large tank.

[Curtis]

Re: Just bought my first CNG vehicle and need some advice

One last question that comes to mind, does anybody know what the capacity is on the conventional gas tank on the F150s?

Capacity is probably around $150-$200.

[David Burklin]

Re: Just bought my first CNG vehicle and need some advice

Picked up my truck and made a nice road trip to get aquainted with it. I have to say I love CNG even more than I thought I would. Saved a bundle on the trip, except for the long I40 stretch with no CNG available.

Once I hit Oklahoma and made it to Elk City, I was tickled to death to pump $8 at the pump. I've watched my daily work commute got from >$15/day to ~$6/day. Nice little savings in the pocket at the end of a week!

Just over a week having it and I recommend everybody gets a NGV.

Anyway, to be prepared for the inevitable, who in the Tulsa area is qualified to work on my CNG system? Can a non-CNG certified mechanic work on the rest of the power train, or do I need a CNG guy for everything now? I'm not expecting a problem tomorrow, but would like to know who to call on when the time comes.

Thanks!

[cngbuck]

Re: Just bought my first CNG vehicle and need some advice

Only the CNG system requires a CNG/Alt fuel certified mechanic. You can have Tom at Tulsa Gas Technology look at the CNG system in Tulsa, and I know David Stanley Ford in OKC has a certified mechanic.