gas mileage = WOW

[futuregx]

hey guys,

I got incredible #'s on my last fill. I was approaching 200miles and I still had 4 bars left to go. I've been reading on the forum that someone got 300+miles on the tank and now I know that's possible.

This was with 90% fwy driving at around 75mph with no ac.

[topaz420]

Re: gas mileage = WOW

I've had wildly varying ranges with stations that all claim 3600psi and 100% fills.

At San Fernando City Station, I get about 140-150 miles :O

At Clean Energy Burbank, I get about 230

I have no idea how someone could get 300, but I do know a station near Curtis in Lancaster gives like a 4000psi fill.

[Linda]

Re: gas mileage = WOW

The best I have done: Hillsboro to Medford 282 mi, all I-5, 55mph cruise, ambient air about 25f. Warning light was on for the last 28 miles. Dont try this in hot weather unless you have AAA+.
Linda

[mecklen]

Re: gas mileage = WOW

Don't try this in hot weather unless you have AAA+.

Just curious, why do you believe the ambient temperature should affect the mileage?

[futuregx]

Re: gas mileage = WOW

Just curious, why do you believe the ambient temperature should affect the mileage?

cooler air has more density... more air = more power = more efficiency

[CNGfamily]

Re: gas mileage = WOW

Just curious, why do you believe the ambient temperature should affect the mileage?

It might be that the CNG fill was better at the cooler temp (if the fill wasn't "properly" temperature compensated and something close to 3600 psi was filled, then that's a LOT more fuel than you get at 70 F!)

[freedml]

Re: gas mileage = WOW

Sometimes you just get a higher fill than usual. I think I've gotten as high as 4000.

[Green GX]

Re: gas mileage = WOW

I've done 290.6 miles with 2 bars still lit and no bingo light. As I recall it worked out to around 46 mpg.

Unfortunately, the pump I use, CE in Santa Clarita, doesn't have any pressure gauges. (I e-mailed the ScanGuage people to see if their gizmo can read GX tank pressure, but no reply.)

Someone else said the record is held by an American Honda employee, but he had to admit that the last few miles were with the GX hooked up behind a tow truck.

Bill

[ch4]

Re: gas mileage = WOW

The best I have done: Hillsboro to Medford 282 mi, all I-5, 55mph cruise, ambient air about 25f. Warning light was on for the last 28 miles. Dont try this in hot weather unless you have AAA+.
Linda

So, Portland to SLC is done. Running on empty. With a beer stop in Chico. Not recommended but done.
Linda, what year is your GX?

[Cal]

Re: gas mileage = WOW

I've done 290.6 miles with 2 bars still lit and no bingo light. As I recall it worked out to around 46 mpg.

Unfortunately, the pump I use, CE in Santa Clarita, doesn't have any pressure gauges. (I e-mailed the ScanGuage people to see if their gizmo can read GX tank pressure, but no reply.)

Someone else said the record is held by an American Honda employee, but he had to admit that the last few miles were with the GX hooked up behind a tow truck.

Bill

I also fill sometimes at the Santa Clarita CE station. I've had 160 miles with 7 or 8 bars left. I refueled with a 60 mile RT drive ahead of me because I thought that the trip mile counter on my GX was faulty. Perhaps not. After I topped off the tank I noticed that I had only used 3.5 gallons. That equals nearly 50 MPG. Even though the Santa Clarita CE station is more expensive ($2.80 as of 10/17/08) I do get more miles per tank. I'll take that.

[TheBundo]

Re: gas mileage = WOW

hey guys,

I got incredible #'s on my last fill. I was approaching 200miles and I still had 4 bars left to go. I've been reading on the forum that someone got 300+miles on the tank and now I know that's possible.

This was with 90% fwy driving at around 75mph with no ac.

Try 100% freeway at 50 mph. You can do it. 75 mph is not very efficient

[RaulLasVegas]

Re: gas mileage = WOW

A 3600# fill will always take me > 250 miles unless I use the AC. I have been above 290 miles twice this year. Thats driving 70. If I drive 65, I will get 44MPG concistantly (using the data for 3 fillups)

Tempurature compensation. I still dont get this. The pump is calibrated, and certified. The pumps I use say that a GGE is 5.66 pounds. Weight is weight no matter how cold it is. It takes up more volume warm, but its still weights the same. A 3600# fill at 4 degrees will take me no farther than a 3600# fill at 80 degrees. My records just dont show that.

I have noticed that the old school method of using the current fill to figure out how much gas you used in the last tank is not accurate at all. Fills vary way too much for that to be of any value. MPG has to be figured over 3 tanks with those three fills.

I only fast fill, and I have an 07.

[Cal]

Re: gas mileage = WOW

250 miles with three bars left! I filled up at the CE Santa Clarita station. OH, WOW!

[BRodri]

Re: gas mileage = WOW

that is strange on one of the pumps i use in oklahoma it says like 102 cu. ft is a gge. i think that would change with the temp wouldn't it?

[Franz]

Re: gas mileage = WOW

The GGE (gasoline gallon equivalency) is as controversial now as ever. Take a raw BTU value for gasoline, somewhere around 120,000 (and that number varies everywhere), and the raw heat value for a cubic foot of natural gas, from 950 to 1075, but 1025 seems to be the average, and divide the NG in to the gasoline number and we get somewhere around 117 cubic feet equals one gallon in energy equivalency. Some people insist on using high heat values for one and low heat values for the other, but we need to keep apples with apples, keep the heat values the same.

As for the pressure and temperatures, when gas is transferred from the dispenser to the tank, the pressure in the tank increases as does the temperature. The dispenser senses the pressure and when it reaches the intended maximum limit, it turns off, irregardless of what the temperature is. If the tank pressure is increased to overcome the pressure settling, it over-pressures the tank by as much as 20%. Some systems have tried to cool the fuel before it passes through the dispenser but that is only partially successful.

The best method of filling is still the slow or time fill and let the temperature dissipate normally.

Franz