Hemingway Posted April 10, 2013 Share Posted April 10, 2013 QUIT DRIVING YOUR TANKS TO E... you clog the fuel filter much faster when you allow the fuel pump to suck up the debris at the bottom of your tank... Sure it allows easier calculation of MPG... but clogging the filter only lowers your MPG faster.. Ok, I'm confused. Help me understand. As I understand it, the fuel pump necessarily reaches to the bottom of your tank to pump out the gas ... otherwise it wouldn't use the full capacity of the tank. In addition, every time you fill up and the car is in motion, any particulate is stirred up anyway. Finally, I've seen into gas tanks that are decades old and most are very clean (as the constant circulation would cause the particulate to regularly pumped out) and the fuel filter is designed to help clean up the occasional 'dirty' gas pumped into the tank. Are my assumptions and experience wrong? I know the arguments for condensation buildup in a nearly empty tank and potential overheating of the fuel pump. But I am having a harder time understanding the dirt argument. Link to comment Share on other sites More sharing options...
Bassnectar Posted April 13, 2013 Share Posted April 13, 2013 It probably ends up in the filter regardless. But I will post update this with some of the links I have read when I get home so you can have more information to base the argument. But you are. Correct it all gets stirred while in motion, but gravity keeps the majority of it at the bottom, when the fuel level is very low or only a inch or so above the bottom all the rust / dirt is put in a motion towards and back from the fuel pump as you accelerate and decelerate s causing a higher crap:gas ratio. Also the fuel pump is cooled by fuel so running dry could potentially overheat it. More crap less gas = possibly lowered octane Sent from my Nexus 4 using Tapatalk 2 Link to comment Share on other sites More sharing options...
Hemingway Posted April 13, 2013 Share Posted April 13, 2013 Thanks ... and, for the record, I usually refill the tank at half empty ... I just like seeing the needle at 'Full.' Link to comment Share on other sites More sharing options...
spooln30 Posted April 13, 2013 Share Posted April 13, 2013 I agree running the tank low can cause the pump to prematurely due to the gas cooling the pump. With the garbage on the bottom getting sucked up when your low isn't entirely true. The pump will suck up anything that is within the reach of the suction of the pump regardless of how much gas is in the tank. Most will get caught by the first filter that is attached to the pump itself. Link to comment Share on other sites More sharing options...
twisty Posted April 16, 2013 Share Posted April 16, 2013 out of all the vehicles ive had with in-tank pumps, ive only had 2 need new fuel pumps. the civic lost the fuel pump when it was a full tank, at night in the winter. the suburban lost the fuel pump right after i filled the tank (42 friggin gallons) in the summer. i usually forget to fill the tanks on my vehicles until that little light goes on. not because i feel the need to wait that long, just because i procrastinate. a lot. Link to comment Share on other sites More sharing options...
Fire Away Posted May 1, 2013 Share Posted May 1, 2013 I finally did a complete fill up after a little over 1k miles since my last recorded reading of around 26.8mpg. I got 28.8mpg over those miles. That number, however, would have been higher had I gotten my tires balanced sooner and had I not been running late for work a few days. I think that I can probably get closer to 30mpg, if not break it, on my next tank. I also started doing a few of the more reasonable hypermiling techniques. Link to comment Share on other sites More sharing options...
twisty Posted May 5, 2013 Share Posted May 5, 2013 I ran the new ft until it sputtered this weekend. Low fuel light came on at 337 miles and it sputtered at 395. Filled it with 15.7 gallons. Did the same to my wagon when i got it and was 335 and 379 miles, but only took 13.5 to fill from empty. I was surprised to get almost 400 to a tank. I've been driving it normal and spirited during this tank Link to comment Share on other sites More sharing options...
charmzdub Posted May 9, 2013 Share Posted May 9, 2013 hey guys, haven't been on here in like a year now lol. Currently, my '99 LGT-L (5-spd) only has 80,500 miles on her and is getting great gas mileage. I drove it up here back in march for the last few months of college- (grand forks, ND) from madison, WI. the trip was about 600 miles and it was all highway. went 68mph to minneapolis and then 75mph all the way across MN and up to grand forks. got 29.3mpg on the first tank which went almost 400 miles i think. took another half tank to make it the rest of the way (another 200 miles). such a rare and awesome car. owned it for about 2.5 years now. unfortunately last week, i was running her on fumes for a few days and then she ran out when i started her one night ;( first time ever, but i was literally broke so I culdnt put in more than a gallon after a friend took me to the station to get some lol. ran a bit rougher too, probably because i put 87oct in and i always use 89. anyway the next day i got paid and filled her up with 89, running a lot more smoothly again now. had the original fuel filter replaced when i got the car a few years ago so I definitely don't need a new one. good to see people still post stuff here! woohoo! Link to comment Share on other sites More sharing options...
Fire Away Posted May 21, 2013 Share Posted May 21, 2013 30.5mpg on my last fill up. I got 395 miles out of that tank and the fuel level needle was about .5mm away from completely covering the E mark. The low fuel light never came on. I could have probably gotten the extra five miles just to hit 400. The current tank, I am less than half way between 3/4 and 1/2 and the trip odo shows 180 miles travelled. I'll get 400 miles out of this tank provided I don't hit any traffic (or run late for work). Dumb question since I haven't looked at the owners manual yet, but does my 98 L even have a low fuel light? Link to comment Share on other sites More sharing options...
cal71919 Posted May 22, 2013 Share Posted May 22, 2013 When I fill up, I usually only get 12 or so gallons into it. If I remember correctly, my manual says it has a 15.9 gallon tank. I only squeeze in another half gallon or so after the initial cutoff. Am I missing something? (Other than 4 gallons) Link to comment Share on other sites More sharing options...
Zues Marine Posted May 22, 2013 Share Posted May 22, 2013 there's probably the 4 gallons still in your tank, the gauges on these cars are so hit and miss when it comes to the 'fuel light' coming on and there's really no remedy for it aside from running your tank to E completely and filling up from there Link to comment Share on other sites More sharing options...
987687 Posted May 22, 2013 Share Posted May 22, 2013 When I fill up, I usually only get 12 or so gallons into it. If I remember correctly, my manual says it has a 15.9 gallon tank. I only squeeze in another half gallon or so after the initial cutoff. Am I missing something? (Other than 4 gallons) Then you're not using up all the gas... plain and simple. Is your low gas light coming on? On both my 96L and 98LGT if I filled it up right as soon as the light came on, they'd take about 14 or so gallons. At that time, the needle was usually below the E line. If I kept driving for another 50 or so miles it would start running really crappy up hills as the gas sloshed in the tank... You're not pushing it far enough. Link to comment Share on other sites More sharing options...
cal71919 Posted May 22, 2013 Share Posted May 22, 2013 I didn't realize I had a low fuel light. I'm gonna pack a gallon of gas at the end of the week and see just how much gas is in there. Link to comment Share on other sites More sharing options...
Fire Away Posted May 22, 2013 Share Posted May 22, 2013 In my case it was 12.95g and the low fuel light still wasn't on. Link to comment Share on other sites More sharing options...
987687 Posted May 23, 2013 Share Posted May 23, 2013 In my case it was 12.95g and the low fuel light still wasn't on. Well I said it comes on at about 2 to 2.5 gallons. You said you put 13 gal in a 16 gal tank, that's 3 left. So yea, I'm not surprised it didn't come on. Link to comment Share on other sites More sharing options...
PorkchopSandwiches Posted May 23, 2013 Share Posted May 23, 2013 I have a digital fuel gauge on my Scangauge II so I keep track of fuel levels on that. It says the low fuel light comes on at roughly three gallons. I've driven it as low as 1 gallon remaining but past that I get nervous. Link to comment Share on other sites More sharing options...
987687 Posted May 23, 2013 Share Posted May 23, 2013 It'll start running really crappy and eventually start stalling up hills. I put 15.8 gal in my tank once.... Link to comment Share on other sites More sharing options...
twisty Posted May 23, 2013 Share Posted May 23, 2013 my GT starts to sputter at about 15.7gal down. enough to get me to the gas station, but i really hate running it dry. the light sometimes comes on at 12.5, sometimes at 13.5 gone. either way it gets about 400 a tank, so im still happy. i get 300 a tank out of my truck, but thats 25 gallons. Link to comment Share on other sites More sharing options...
Jeff98GT Posted May 23, 2013 Share Posted May 23, 2013 Looking at the MPG you guys are getting, it looks like i have some work to do. I barely get 300 miles from a full tank. Already did the Seafoam thing, replaced spark plugs, and replaced air filter. Tires are in good shape,and at the proper PSI too. Detective work sucks. Link to comment Share on other sites More sharing options...
Zues Marine Posted May 23, 2013 Share Posted May 23, 2013 Where all did you seafoam? Link to comment Share on other sites More sharing options...
DOHCEJ22E1 Posted May 23, 2013 Share Posted May 23, 2013 Recorded 28c/36h after some modding & the DOHC conversion for the EJ22 I swapped in. Now, the city mileage hasn't changed but the highway miles have, thanks to the new stock exhaust so readings are 26c/34h. If I put a higher flowing exhaust back on, my mpg numbers & midrange will go up but my low-end TQ will drop. Btw, I get about 100mi every quarter tank if I am traveling mostly freeway. City traveling will cut me down to about 75mi every quarter tank. Link to comment Share on other sites More sharing options...
Jeff98GT Posted May 23, 2013 Share Posted May 23, 2013 Where all did you seafoam? Followed the tips that i found on the forum. Seafoam in the tank, in the oil, and through the PCV. It made a difference, not just a whole lot. I'm probably going to do the Big 3 improvements to the current ground wires some time soon. Basically, I'll just do a checklist of common maintenance issues that should be done on a car with over 130K on the odometer. Link to comment Share on other sites More sharing options...
Fire Away Posted May 23, 2013 Share Posted May 23, 2013 Did you seafoam before or after new plugs? I have read on a Tacoma forum I also frequent that the PCV valve operation can foul plugs. If you did it after putting new plugs in you may want to give it a look. I saw a ~2mpg increase after I put in a new air filter (standard paper kind) and fuel filter as well as cleaning my MAF and throttle body. I have not seafoamed my engine yet and the oil in it is just standard dino oil. I don't want to seafoam anything until I fix two minor oil leaks. Link to comment Share on other sites More sharing options...
ljshein Posted May 24, 2013 Author Share Posted May 24, 2013 It's Nice to see that my simple question gets people excited about fuel economy I'm such an idiot sometimes... I have to constantly remind myself that we have to do the simple things first before we look at the more complicated stuff... when I checked the air pressure in the tires, all 4 were about 22 pounds. I brought all 4 up to 35 psi and the mileage jumped on the next tank from 19 to 22. It's been consistent from 21 to 23 since then. I do mostly around town with some longer stretches at 50 mph. Lesson learned, check your tires!! oh and someone asked about the gas light... mine typically comes on for a few miles when I hit 280 miles then it will go off again until I hit 305-310. I usually don't go more than 315 on a tank and I'm putting about 15 gallons in. Link to comment Share on other sites More sharing options...
987687 Posted May 24, 2013 Share Posted May 24, 2013 I usually fill my cars up at 1/4 tank. Why? I'm gonna have to fill it up anyway, why tempt fate.... running out of gas sucks. heh. Link to comment Share on other sites More sharing options...
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