Altitude, Cold temps, and issues as a result with dedicated CNG

[SkiGreen]

Hello folks,

I plan on running a dedicated CNG passenger van at altitudes ranging from 7500 - 9200 feet in Colorado during both the Winter and Summer, and was curious about problems that could arise as a result. I have heard that above altitudes of 8000 feet in the dead of winter I may have issues with cold starts. I would fit the van with a spare tank as to give it a range of 300 miles to 350 miles so that I would not have to refuel while up in the mountains. Anyone know if I would encounter any significant problems? Any ideas as to what type of passenger van would be suited best for this environment/situation? I would like to fly out to CA and purchase a dedicated passenger van from an auction as I can not afford a brand new van + the conversion, or a brand new dedicated van either.

Any suggestions/ideas would be greatly appreciated!

Thanks everyone!

Walt

[Clean Energy - CO]

Re: Altitude, Cold temps, and issues as a result with dedicated CNG

We have some vans I have run up to Summit County a few times and my civic takes regular trips via I-70. I havent had any major problems, but have noticed some power loss at really high altitudes, which is consistent with what I have heard in the past.

I have some converted vans Fueltek here in Denver did for us and have not had any problems with them in extreme cold. They made it through the last blizzard with flying colors.

Our entire operations team in Denver runs a fleet of vans year round and has been doing so for years.

[SkiGreen]

Re: Altitude, Cold temps, and issues as a result with dedicated CNG

How serious is the power loss? Would the vans still be able to drive over 50-60 MPH and make it up Vail and Loveland passes? Are there any refueling stations up in Summit County any more?

[larrycng]

Re: Altitude, Cold temps, and issues as a result with dedicated CNG

Basic engine design theory will tell you that you will loose about 3% of your horsepower per 1,000 ft of altitude increase (actually 3-1/4%). But on the good side you should pick up a slight increase in hp as the air intake temperature decreases, but not much.

larrycng

[Clean Energy - CO]

Re: Altitude, Cold temps, and issues as a result with dedicated CNG

The only studies have seen are consitent with what Larry said above, a 3% decrease for every 1000ft beginning at about 7,000 ft. This is true of most vehicles, not just CNG.

I think you should be fine on Vail and loveland, however if you are going 60mph on loveland pass you will probably not be around long anyway.

I have taken our van with six passangers over loveland a few times without major issue.

No stations in Summit county right now, but we are working on one, however my guess is at best it is still a year away.