Comments on: Century Joins Other Local Governments In Natural Gas Vehicle Push

By: Nathalie Bowers, ECUA Public Information Officer

Nathalie Bowers, ECUA Public Information Officer — Wed, 30 Oct 2013 19:05:21 +0000

David,
Yes, I believe that is the explanation I was given several months ago about why the wear on the brakes is so dimished. Thank you for contributing that.

CNG User,
Yes, there is less power with the CNG– however, that is why it is so well suited to our fleet of sanitation trucks. They do not need to get up to very high speeds between pick-ups from house to house, especially in the more densely populated portions of our service area, where the distances between homes are so small.

By: CNG user

CNG user — Wed, 30 Oct 2013 08:49:02 +0000

Cost will definitely reduce to half or even less. e.g. if you cover a distance in 6 bucks on Diesel then you’ll cover same distance in 3 bucks on CNG.

But CNG will not provide as much power as Diesel or Petrol, but still its cheap and environment friendly.

By: David Huie Green

David Huie Green — Tue, 29 Oct 2013 22:21:57 +0000

Nathalie,
Most likely the brake life improvement is tied to the system which captures energy of motion while stopping and uses it when starting to move again. That would reduce brake wear because the brakes wouldn’t be doing as much work as well as improve fuel economy because kinetic energy would be conserved.

Just a guess, though.

David for useful energy conservation

By: Nathalie Bowers, ECUA Public Information

Nathalie Bowers, ECUA Public Information — Tue, 29 Oct 2013 15:05:06 +0000

Mr. Jeeperman,
Our results indicate average mpg of 1.8mpg on diesel; 3.3 mpg with CNG. I’ll be glad to get more info on that from our fleet manager if you’d like.

Thank you, David Huie Green, for the more detailed explanation of the gallon equivalent. Yes, you are correct.

For I Drive One,
The trucks were not retrofitted diesel vehicles. They are original CNG. I will have to get more details on the brake systems that our CNG vehicles have from our fleet manager. That might take a day or so as I am not in the office today. I will send the info to William and perhaps he can forward that to you if you wish.

By: I Drive One

I Drive One — Tue, 29 Oct 2013 00:28:59 +0000

The mileage for gas or CNG is nearly identical on a Ford F150. While gas prices are coming down slightly the price we pay for CNG has not. Still at $1.96(much more than centurys $1.00)a gallon it provides quite a savings.

But a question for Ms. Bowers,
How does fuel type help save the brakes on what was a diesel vehicle?

By: David Huie Green

David Huie Green — Mon, 28 Oct 2013 22:56:03 +0000

c. w.,
They are saying gallon-equivalent, not gallon. The energy released by burning one gallon of gasoline or diesel is the amount of energy released by burning the gallon-equivalent amount of natural gas. Since they both heat the compressed air-fuel mixture in the engine, the power output should be comparable, fuel economy comparable but natural gas combustion more complete.

David for better methane use

By: jeeperman

jeeperman — Mon, 28 Oct 2013 20:51:22 +0000

Nathalie Bowers,
Please review your mpg numbers again. If your fleet mileage is about double that of diesel fuel, or better your some how breaking the rules of physics.
The universal formula is that you will get about 90% of the MPG you got on diesel.
i.e if the trucks were getting 5mpg on diesel, they will get 4.5mpg on CNG.
There is no way around it.
Of course if the old trucks had 12 liter diesels and the cng trucks have 4 liter engines…………………..

By: fred

fred — Mon, 28 Oct 2013 19:01:53 +0000

@c.w. – your question is well put. But, don’t think you’ll find an objective truthful comparison anywhere. The only data I have found on the web is sponsored by natural gas companies, and that data is, of course, suspicious. We’ll have to rely on real life experience from users to see what the mileage truly is. Remember how we were (and still are) told how great Ethanol is, but we also know that mileage suffers, it attracts and holds water (ever see the mildew around gas caps on light color cars?), and dissolves rubber components. CNG won’t do those things, but it is a high pressure fuel, and we’ve all seen what gas leaks can do. This will be interesting to say the least.

By: Nathalie Bowers, ECUA Public Information

Nathalie Bowers, ECUA Public Information — Mon, 28 Oct 2013 18:50:01 +0000

Response to c.w.:
The mileage is about double that of diesel fuel, or better. Since July 2012, we have seen savings not only in the price per gallon and in mileage efficiency, but also in the operating costs and maintenance– we’ve seen considerably less wear on the brakes and have eliminated the need for diesel particulate filters (DPF) the the vehicles’ exhaust systems. We estimate a saving of $16,000 per vehicle considering the changes with the brakes and DP filters. We have 50 trucks in our Sanitation fleet, and 72 vehicles in all now have CNG capability. We expect that over the life of the vehicles, each will save about $56,000.

for Shiloh:
CNG is particularly well suited to a fleet such as ours because the vehicles are refueled at night (we have 90 slow-fill bays at the Pine Forest station) and the tanks are sized appropriately for the mileage each covers daily. I think a lot has changed in the CNG industry in the last few years.

By: just listening

just listening — Mon, 28 Oct 2013 13:43:27 +0000

Congratulations to Mayor McCall and the entire Century Town Council for making the decision to go to natural gas. Maybe soon all the city vehicles will be running on natural gas. A dollar saved is a dollar earned is what my Dad taught me. In order to give our future generations a cleaner environment we all need to go “Greener”. I look forward to the day when all New vehicles come with the equipment to run Natural gas.