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Author	Topic: Last 1/4 in tank seems to go fast.	Topic is locked Back to Topics

Terzo All-Star Author Orange County Posts:653 Points:116,565 Joined:Mar 2012	Message Posted: Mar 22, 2012 4:07:06 PM Ignore Terzo Report Abuse Anybody else notice that the last 1/4 in their gas tank seems to burn up faster than at any other level? When I first bought my truck it seemed to be more consistent, but now I have to keep the tank at a higher level or I'll burn fuel too fast. You'd think with less weight to carry around that I'd be getting better gas mileage, but I'm experiencing just the opposite. Anybody got any ideas what's going on?

Terzo

All-Star Author
Orange County

Posts:653
Points:116,565
Joined:Mar 2012

Message Posted: Mar 22, 2012 4:07:06 PM

Ignore Terzo Report Abuse

Anybody else notice that the last 1/4 in their gas tank seems to burn up faster than at any other level? When I first bought my truck it seemed to be more consistent, but now I have to keep the tank at a higher level or I'll burn fuel too fast. You'd think with less weight to carry around that I'd be getting better gas mileage, but I'm experiencing just the opposite. Anybody got any ideas what's going on?

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sagnat Champion Author Riverside Posts:1,144 Points:306,310 Joined:Jun 2012	Message Posted: Jan 7, 2013 1:05:19 PM Ignore sagnat Report Abuse Probably because the fuel gauges aren't linear but rather a best guess on how uch is remaining.
hornet17 Champion Author Vancouver Posts:1,323 Points:440,865 Joined:Aug 2011	Message Posted: Jan 7, 2013 10:04:33 AM Ignore hornet17 Report Abuse inaccurate fuel gauge? Most of them are.
musicreporter All-Star Author San Antonio Posts:620 Points:132,265 Joined:Dec 2012	Message Posted: Jan 7, 2013 9:53:57 AM Ignore musicreporter Report Abuse yes
wlotocky All-Star Author Florida Posts:805 Points:203,185 Joined:May 2010	Message Posted: Jun 15, 2012 1:04:50 AM Ignore wlotocky Report Abuse yup
Seamus4513 Champion Author Orange County Posts:2,573 Points:384,630 Joined:Mar 2012	Message Posted: Jun 14, 2012 4:00:22 PM Ignore Seamus4513 Report Abuse I havent noticed. In my old ES, my avail fuel increased in hard right turns
minet Sophomore Author British Columbia Posts:150 Points:74,425 Joined:Jun 2012	Message Posted: Jun 11, 2012 9:16:51 PM Ignore minet Report Abuse yeah the lower the level of fuel, the faster it burn out. i always fill up when its 1/2 tank. i get more milleage everytime.
nordlead Veteran Author Syracuse Posts:295 Points:118,865 Joined:Jun 2011	Message Posted: Jun 11, 2012 1:09:56 PM Ignore nordlead Report Abuse when near empty, I can gain 1/8th of a tank just by driving up a hill :-D Until (as mentioned below) there is a system to measure input and output of the gas tank no gauge will be very close to correct. I just watch my trip meter and reset it at every fill-up.
Jude23 Rookie Author Vancouver Posts:36 Points:3,780 Joined:Jun 2012	Message Posted: Jun 10, 2012 10:12:49 PM Ignore Jude23 Report Abuse Yes! Drives me crazy too. I always gas up in the states and if I've not watched my amount of driving and am coming close to that 1/4 tank mark it's scary how fast it can plummet while I'm doing 110kph heading for the border! :)
prob52 Rookie Author California Posts:1 Points:20,170 Joined:Jun 2012	Message Posted: Jun 9, 2012 7:54:44 PM Ignore prob52 Report Abuse My gas light comes on when I have 50 miles left. I usually put gas in when the light comes on.
diesdown Champion Author North Carolina Posts:1,700 Points:510,000 Joined:May 2011	Message Posted: Jun 9, 2012 6:03:36 PM Ignore diesdown Report Abuse That's because it most likely is NOT a full 1/4 tank......instrument measurements vary greatly.
vikings80 All-Star Author South Dakota Posts:781 Points:110,065 Joined:Aug 2008	Message Posted: Jun 8, 2012 9:15:55 AM Ignore vikings80 Report Abuse quick
kxy4fw Champion Author Denver Posts:1,226 Points:275,255 Joined:Nov 2011	Message Posted: Apr 27, 2012 9:23:21 AM Ignore kxy4fw Report Abuse reallllll fast!
dontuknowOH Champion Author Ohio Posts:2,098 Points:36,565 Joined:Aug 2009	Message Posted: Apr 26, 2012 12:53:01 PM Ignore dontuknowOH Report Abuse The shape and angle of the fuel tank is different on some vehicles,plus where it is placed for safety sometimes determins the capacity at different fuel levels. Others have mentioned linear reading at the guage indicator may be designed a bit crude,that's often the case,same for sample readings by the ecu on more modern vehicles. It's not good to always rely on the low fuel light before adding fuel myop.The other reason may be you just watch the guage more when running close to empty,concerned about the nearest location for refueling.Gas cans are no longer a cheap ticket item,but having one on board,well.....they are hard to borrow from strangers! LOL
JCLNC All-Star Author Greensboro Posts:902 Points:218,460 Joined:Jun 2011	Message Posted: Apr 23, 2012 3:57:40 AM Ignore JCLNC Report Abuse I try not to let my tank go below a 1/4.
cheapmonkee Champion Author Portland Posts:30,300 Points:3,169,460 Joined:Jun 2004	Message Posted: Apr 23, 2012 1:23:43 AM Ignore cheapmonkee Report Abuse I keep mine fairly full. The largest fill this year was 7.75 gallons. My tank is a little more than 12 gallons.
Z12 Champion Author Toledo Posts:3,647 Points:756,760 Joined:Mar 2011	Message Posted: Apr 22, 2012 8:50:37 PM Ignore Z12 Report Abuse Yes, it does
Titanic1985 Champion Author South Carolina Posts:6,246 Points:356,370 Joined:Dec 2010	Message Posted: Apr 22, 2012 6:50:19 PM Ignore Titanic1985 Report Abuse Hello Terzo. I've read the posts on this thread and the conclusion of non-linear gas guages is correct. That said, there is another factor involved. Last year, I read an automotive article regarding gas guages and it is a no win situation for the manufactures. If a gas guage goes off full after just a few miles of driving, the driver feels the vehicle is getting poor gas mileage. If, on the other hand, the guage stays on full longer, that same individual thinks the vehicle gets great gas mileage. Since the guages are based on a float system in the tank connected to a variable resistor to the guage, the manufactures tend to keep the guage at full longer followed by a more rapid plunge to empty. It is, in reality, a marketing ploy and was well documented in this article using the same drivers and the same vehicles. I never thought of this issue until I read the article.
Tweak3D Rookie Author Tacoma Posts:34 Points:30,865 Joined:Jun 2011	Message Posted: Apr 20, 2012 9:42:27 AM Ignore Tweak3D Report Abuse A linear fuel gauge would be nice, but isn't so easy to design and maintian between multiple lines of vehciles. This is because of the shape of the fuel tank changes making each fuel take require a unique calculation. Newer cars are better because they use a combination of the feed back from the fuel tank sensor along with fuel flow #'s from the injectors and can give us a fairly accurate idea of how we are doing.
JimBlake56 Veteran Author Akron Posts:376 Points:75,060 Joined:Oct 2010	Message Posted: Apr 12, 2012 11:54:56 AM Ignore JimBlake56 Report Abuse Non-linear fuel gauge is pretty common. Sometimes the divisions on the gauge are skewed to reflect that, for example the space between empty & 1/4 is big, then the space between 1/4 & 1/2 is smaller, etc. Sometimes 3/4 is very close to the top. On some cars the gauge actually works that way, but the stylists have decided that it looks better if the gauge divisions are evenly spaced.
mnrick041 Champion Author Twin Cities Posts:14,291 Points:1,367,110 Joined:Jun 2009	Message Posted: Apr 10, 2012 1:13:27 AM Ignore mnrick041 Report Abuse I had a car once that seemed to stay at full for a long time, then it would drop, stay at about 3/4 for awhile and then it would drop like a rock. My car I have now shows me "miles to E" on a dash readout, that is a little more informative than the old gas gauges were.
13Octane Champion Author Tucson Posts:2,147 Points:332,165 Joined:Aug 2005	Message Posted: Apr 2, 2012 11:50:34 AM Ignore 13Octane Report Abuse nope
RacerGene Champion Author Alabama Posts:1,703 Points:366,225 Joined:Jan 2012	Message Posted: Apr 2, 2012 9:56:49 AM Ignore RacerGene Report Abuse just the meter that's not accurate
forresj Champion Author Wilmington Posts:2,772 Points:541,305 Joined:May 2005	Message Posted: Apr 2, 2012 9:10:01 AM Ignore forresj Report Abuse no i never let the tank drop below 1/4.
MertieMan Champion Author Lexington Posts:14,778 Points:2,893,660 Joined:May 2005	Message Posted: Apr 2, 2012 7:44:46 AM Ignore MertieMan Report Abuse You shouldn't let your tank get this low.
WEDDY Champion Author Phoenix Posts:3,234 Points:1,035,570 Joined:Oct 2009	Message Posted: Apr 1, 2012 8:03:32 PM Ignore WEDDY Report Abuse Yes.
Jescareno22 Veteran Author Toms River Posts:303 Points:58,070 Joined:Mar 2012	Message Posted: Apr 1, 2012 7:32:19 PM Ignore Jescareno22 Report Abuse no
KansasGunman Champion Author Kansas City Posts:21,434 Points:2,104,400 Joined:Oct 2005	Message Posted: Apr 1, 2012 6:09:43 PM Ignore KansasGunman Report Abuse Wouldn't know...can't remember the lat time we let the tank get below half on any of our vehicles.
jamieg2012 Veteran Author Sioux Falls Posts:286 Points:11,385 Joined:Jan 2012	Message Posted: Apr 1, 2012 1:43:34 PM Ignore jamieg2012 Report Abuse part of it is how much gas gets on the sensor for how full as it moves you will go back and forth from reading empty to about half that is what my car usually does and it is based of pressure caused by more fuel so the road grade changes to give you a hill that goes up some and it makes gravity pull all the gas back to the sensor and you read more than is there - only a level parking spot will give you the right reading since even driving changes how much pressure on the sensor since stopping and the gas will still keep going forward until it hits the front of the tank then settle back down
pacecar68 Champion Author Oakland Posts:4,656 Points:866,120 Joined:Jan 2007	Message Posted: Apr 1, 2012 12:53:25 PM Ignore pacecar68 Report Abuse you are gambling by letting your tank get below 1/4 a tank. the fuel is a coolant for the fuel pump. burn the pump up and you will be surprised at how expensive to replace.
DCD_Guy Rookie Author San Francisco Posts:68 Points:43,075 Joined:Jan 2012	Message Posted: Mar 27, 2012 3:05:45 AM Ignore DCD_Guy Report Abuse It's the fuel gauge designed like that, non-linear to emphasize the most concerned area. Try a digital fuel meter, you will get linear readout. The engine will not burn faster like you said. Let me know if you need help to do the test with a good linear meter.
sluggopyle Champion Author North Carolina Posts:23,608 Points:1,075,890 Joined:Dec 2005	Message Posted: Mar 25, 2012 12:51:44 AM Ignore sluggopyle Report Abuse => You get the best gas mileage on a full tank and the last quarter tank does have a lower MPG than the 1st quarter mile if you went by your meter. <= No. You don't. You're looking at a non-linear gauge; the "1/4" mark is not really 1/4; it's less. If the marks showed accurately how much gas was in there, they would not be evenly spaced. Conditions being equal, you get the same mileage with the first quarter as you do with the last-- it's just not telling you accurately where either one is.
Pucelle Rookie Author Rochester Posts:33 Points:72,240 Joined:Jun 2002	Message Posted: Mar 24, 2012 7:30:26 PM Ignore Pucelle Report Abuse You get the best gas mileage on a full tank and the last quarter tank does have a lower MPG than the 1st quarter mile if you went by your meter. But if you go on a long trip on the highway using a full tank you will see that you get the same MPG through out the trip so it's just the meter that's not accurate.
greydog13 Veteran Author Iowa Posts:263 Points:490,340 Joined:Feb 2011	Message Posted: Mar 24, 2012 7:09:13 PM Ignore greydog13 Report Abuse I don't generally let the tank get much below 1/2. I fill up more often but it does not hurt as much $$ when I do---
kxy4fw Champion Author Denver Posts:1,226 Points:275,255 Joined:Nov 2011	Message Posted: Mar 24, 2012 9:57:30 AM Ignore kxy4fw Report Abuse Yup.
OceanArcher Champion Author Mississippi Posts:5,693 Points:1,325,450 Joined:May 2004	Message Posted: Mar 24, 2012 9:02:40 AM Ignore OceanArcher Report Abuse Most gas tank metering systems are non-linear. They try to make it such that the gauge movement matches the shape of the tank, but darned few ever manage it. Until we get an integrated system that both measures how much fuel is pumped into the tank, and compares it with the fuel usage, then we will just have to accept there is a level of error in the gauge
gobux10 Champion Author Ohio Posts:3,164 Points:678,010 Joined:Mar 2010	Message Posted: Mar 23, 2012 9:07:25 PM Ignore gobux10 Report Abuse Appears 2
13Octane Champion Author Tucson Posts:2,147 Points:332,165 Joined:Aug 2005	Message Posted: Mar 23, 2012 6:34:30 PM Ignore 13Octane Report Abuse really?
jes Champion Author Pennsylvania Posts:16,155 Points:3,350,525 Joined:Jun 2003	Message Posted: Mar 23, 2012 5:06:40 PM Ignore jes Report Abuse Every vehicle I've owned has been like this. I just come to expect it.
Dennis783 Champion Author Des Moines Posts:13,584 Points:2,701,935 Joined:Sep 2005	Message Posted: Mar 23, 2012 9:27:55 AM Ignore Dennis783 Report Abuse I have noticed that on the fuel gauge. I ignore that and look at the fuel range display
gasmask78 Champion Author Virginia Posts:2,268 Points:443,640 Joined:Sep 2011	Message Posted: Mar 23, 2012 12:53:03 AM Ignore gasmask78 Report Abuse It's because most older cars have little weights in gas tanks.
gougedQC Champion Author Montreal Posts:5,130 Points:69,885 Joined:Apr 2008	Message Posted: Mar 22, 2012 7:30:30 PM Ignore gougedQC Report Abuse I've noticed this as well.. non linear measurement.. I think its a deliberate ploy by the car companies..all of them.. They know most people dont run to empty...but rather to perhaps a little under half..so they skew the readings to make you thing your going farther on your tank of gas..
rick_evans Champion Author Boston Posts:3,713 Points:1,031,760 Joined:Aug 2005	Message Posted: Mar 22, 2012 7:00:12 PM Ignore rick_evans Report Abuse Have you noticed that the first 1/4 tank takes much longer? Every car I've ever owned including my current 07 Corolla has had a non-linear reading fuel gauge which stays pegged at full for the first 50 to 80 miles while appearing to go fasted through the last 1/4 tank.