2008 GX Tank Range

[borckm]

I picked up my 2008 GX about 2 weeks ago, and am struggling with the range. I'm getting about 160 miles in the city, 180 miles on fwy. I've never gotten a fill that registered all the way to the top on the gauge (Last block is always unlit). Also, the most I've ever filled is about 5 GGE's - making me think that although the fuel light is on, there's plenty of fuel left.

Am I doing something wrong, or is this normal?

[Curtis]

Re: 2008 GX Tank Range

There may be a number of factors behind the "reason" for the mileage you're getting.
1) are you running the A/C, if so... there's your answer. A/C has a big impact on your range. There's a thread that address' this question at http://www.cngchat.com/forum/showthr...=1118#post1118
2) Mileage may increase as your engine breaks in. There are additives in your oil right now that help it break-in. Do not do your first oil change until the maintenance minder tells you to.
3) Driving style... You can drive to get there, or drive for efficiency and mileage... but not both. Experiment with the way you drive and see what yields the best results. Many of the members of cngchat play with hyper-mileage techniques to maximize their range.
4) Terrain: Mountain driving, stop and go grid-lock and city driving are all mileage killers.

Some of our members report 45mpg on the hiway. I get around 40 in my '04. I can drop it significantly with the A/c on... so I only use it on downhill stretches. I don't know that it helps, but I pretend it does. And I hope this helps answer your question.

[borckm]

Re: 2008 GX Tank Range

Thanks Curtis! It seems lots of folks have seen A/C affect their mileage.

How many GGE's should I expect the GX to take once the low fuel light is on? The most I've ever filled is about 4.5 GGEs

[Beej]

Re: 2008 GX Tank Range

I think the link Curtis has above talks about it, but you can't really get a "full" tank at a fast fill station. It has to do w/ the heat that is created in the process and the extra pressure that puts into the system. I've heard you can even fill up, let the car sit over night to "cool down" and then get more in the tank the next morning. People also recommend filling at a half tank to get a "fuller fill" but that takes more discipline than I've got.

My experience so far: I do a fair amount of city driving and am still averaging about 35 mpg or so. I fill up when there are only about 3 bars left, anywhere from 180 to 210 miles or so, and usually get just over 5 gallons if the pressure is over 3k. So I just make more trips to the pump than I planned on when I first bought my car. It may be a bit inconvenient at times but it's still one of the best cars I've ever owned. (Though I'm still trying to get used to rotating the tires more often than I change the oil )

[CNG MOTORS]

Re: 2008 GX Tank Range

2005 and older when the fuel light comes on you have 1 gge left. If nothing changed in the 06+ then there you go. Another rookie GX mistake, make sure the transmission is in D not 3. It will "slap" down to 3 if your not paying attention. Most other automatics will stop at the D

[Curtis]

Re: 2008 GX Tank Range

I've never figured out why Honda makes the shifter stop on D3. Every Honda automatic I've seen has had that feature. Even the new ones. I've trained myself to notice when the car feels too responsive/peppy to check the gear selector.

Borckm, there are a lot of variables that effect the number of gge's you can put in the car from empty. Such as, How empty are you, pressure at the pump you're using, outside temp, etc.

Most GX'rs run around with note pads, spreadsheets and calculators (some even have pocket-protectors) and tracking the mileage, gge's and fill pressures on a GX, or any cng vehicle, may come closer to giving them a nervous breakdown than anything else they'll ever encounter.

[freedml]

Re: 2008 GX Tank Range

All of the economy-minded efforts are correct, but I don't think all of them together could give you only 160 miles on a really full tank in an '08 GX. Either the tank isn't ever getting full or there's something wrong. Are you driving it until the low fuel light goes on? Where are you fueling?

[hondatech]

Re: 2008 GX Tank Range

Poor pressures at the pump can give you a bad fill...make sure you fill at a 3600psi pump.

[steven mcclenathan]

Re: 2008 GX Tank Range

I have been driving my GX for about 10 months now and have 28k miles on it.
08' When I first got it I was only getting about 160 miles before I got to 2 or 3 bars. Now I am getting about 200 at 2 or 3 bars. Give it a few miles to break in the engine.

Being in OK I never see anything above the 1st fill mark except for about 3-5 miles.

I will note the huge difference in milage when driving 65(45mpg) vs 80(30mpg) on the highway regardless of A/C being on. I drove a straight run from Tulsa to Joplin and back and got 50 mpg (same station, same pressure)

Again, Give it some time and welcome to cng.

[marlon]

Re: 2008 GX Tank Range

I have an 2006 GX with 38K miles and I have never put in more than 6.3gge and this was at 0 bars on the fuel gauge. Mostly, I put in about 5.8 gges, but this is because I happen to routinely fill up at about 190 miles. Has anyone put in more than this into their GX?

[jpulliam1]

Re: 2008 GX Tank Range

'08 GX with 5K, no bars filled with 6.1 gge

[CNGfamily]

Re: 2008 GX Tank Range

...
08' When I first got it I was only getting about 160 miles before I got to 2 or 3 bars. Now I am getting about 200 at 2 or 3 bars. Give it a few miles to break in the engine...

I had a salesman tell me that part of the "less mileage on a new GX" or any new tank can be explained by the original air that is in the tank prior to the first fill... "you're not starting out with 3600 psi of just CNG" he said.

I bought that arguement hook line and sinker, until thinking about it later... wait... that's only a few cubic feet of air at atmospheric pressures... it's not like you're going to start with a few hundred PSI of plain air in a tank... even if they did a static pressure test of every new tank with nitrogen, they'd clearly vent down to atmospheric pressure before filling it with natural gas for the first time... Such a small amount of nitrogen or air mixed in the CNG would have to be insignificant amount (say less then a half of a percent 16.7/3600 = .46%)

[Curtis]

Re: 2008 GX Tank Range

If you know the GGE's you're adding you must be using public infrasreucture (fast fill). With any fast fill there is heat expansion that will rob you of some of your capacity untill the tank cools, then you should be able to add around 1-1.5 GGE more. Range is also a function of the pressure you get at the station. It can vary significantly from station to station, and time of day if there are traffic demands at that station. Some locations handle trash trucks, school bus, and street sweepers.

Try filling up at night and then top off first thing in the morning. A good strategy if going on a trip where range is critical between fueling stops.

[topaz420]

Re: 2008 GX Tank Range

After averaging 220 or so from Los Angeles stations, I got a mega fill from Barstow the other day and got 300+!

[futuregx]

Re: 2008 GX Tank Range

I have an 2006 GX with 38K miles and I have never put in more than 6.3gge and this was at 0 bars on the fuel gauge. Mostly, I put in about 5.8 gges, but this is because I happen to routinely fill up at about 190 miles. Has anyone put in more than this into their GX?

I filled up at 6.7gge but taht's after driving about 30miles after i had no bars.