Tips on saving on fuel

bahgain on 03/10/2013 - 19:34

I found this information from a car forum and thought I would share it here.

Tip 1:
Only buy or fill up your car or truck in the early morning when the ground temperatures are still cold. All service stations have their storage tanks buried below ground. The colder the ground the more dense the gasoline, when it gets warmer gasoline expands, so buying in the afternoon or in the evening….your litre is not exactly a litre.

Tip 2:
When you're filling up do not squeeze the trigger of the nozzle to a fast mode If you look you will see that the trigger has three (3) stages: low, middle, and high. You should be pumping on low mode, thereby minimizing the vapors that are created while you are pumping. All hoses at the pump have a vapor return. If you are pumping on the fast rate, some of the liquid that goes to your tank becomes vapor. Those vapors are being sucked up and back into the underground storage tank so you're getting less worth for your money.

Tip 3:
Fill up when your your tank is HALF FULL. The reason for this is the more gas you have in your tank the less air occupying its empty space. Gasoline evaporates faster than you can imagine. Gasoline storage tanks have an internal floating roof. This roof serves as zero clearance between the gas and the atmosphere, so it minimizes the evaporation. Unlike service stations, here where I work, every truck that we load is temperature compensated so that every gallon is actually the exact amount.

Another reminder, if there is a gasoline truck pumping into the storage tanks when you stop to buy gas, DO NOT fill up; most likely the gasoline is being stirred up as the gas is being delivered, and you might pick up some of the dirt that normally settles on the bottom.

Automotive

Comments

  • cloudy on 03/10/2013 - 19:45
    +16

    I've heard of the first tip, I'm 100% sure the saving is negligible, to the point it's not even worth considering. And tip 2 and 3 seems like its gas related, not unleaded petrol. Can anyone confirm?

    I think the best tip is the way someone drives, accelerating slower and thus not reaching the higher revs levels, and lifting and coasting will save lots of people significant petrol. Timing the lights as much as possible so u have a rolling start instead of coming to a complete stop is also a big saver.

    Doing those things should save significantly more than tip 1, 2 and 3.

    • viper8548 on 03/10/2013 - 20:01
      +1

      I also think #3 is negligible, the tanks in our regular family cars are way too small (40-80L) for any significant evaporation. Trucks and petrol storage tanks are another story.

    • _Bruce_ on 03/10/2013 - 20:11
      +1

      It is written by an American but refers to petrol. It was written by an American who doesn't understand that these make very little difference.

      Your tips are way better, particularly lifting off early.

    • ntmango on 06/10/2013 - 07:39

      Totally agree that these tips will only save an average person very little fuel. For a big oil company, yes it makes a big difference.
      Also, the storage tanks being inground, under concrete and usually under a roof aswell, im sure it'll take more than a few hot hours to heat up enough to make a big diff.

    • jzdhgkd on 06/10/2013 - 07:47

      Just remember to check both ways if you're doing a rolling start in case there are late red-runners…

    • pao2x on 07/10/2013 - 10:04

      Tip # 3 is not only negligible it can also be flat out wrong. Most gas tanks are sealed if closed properly and the more fuel you have in your car the more weight you carry. In saying that it is best not to run in a near empty tank to make sure the fuel pump is submerged and that your engine doesnt run on fuel gunk from the bottom

    • plmko on 03/10/2013 - 22:35

      Driving in top gear makes sense. For automatics I prefer manufacturers to have shorter gear ratios anyway, gives the car a sportier feel as you can climb to 50km/h faster which is really all you need in metropolitan traffic.

      • slix_88 on 04/10/2013 - 11:11
        +24

        Not necessarily. If you're driving in top gear with your pedal to the metal because there isn't enough torque, you're using more fuel.

        How do I know this? I have my tablet hooked up to my evolution's OBD port and have logged countless runs under different conditions. In the log, I could see there is a higher fuel consumption for a higher throttle position per rpm.

        I've found the following tips to be very useful. By doing the following, I went from travelling 550km on a tank in my Toyota Celica (~11L/100km) to a phenomenal 700km (~7.8L/100km):

        • Gear changes/cruising: Best practice is to cruise in the low 2000s and shift up in the high 2000s. This would vary for each car based on the torque curve but from my experience, it's been a general rule of thumb.NB: When cruising, you should be at around 25% of your throttle position.

        • Launch: Gradually pick up speed and swiftly change gears up as per my first point. Aggressive launches have a big impact on your mileage.

        • Downhill descends (for manual vehicles): When descending down a hill, I would not recommend having the vehicle out of gear as it could be dangerous plus you'll be using some fuel. Put the vehicle into the appropriate gear such that the RPM for your vehicle are above the fuel cut-off threshold.

        • Slowing down (for manual vehicles): When you're approaching a stop, ease off the gas and let the car cruise in gear until it slows down. This way, you allow for engine braking and use no fuel in the process. I also sometimes shift down to a lower gear progressively at appropriate RPMs without riding the clutch too much.

        • Fill tyres up: Flat tyres leading to higher rolling resistance. Make sure your tyres are always filled to its recommended levels (or even +1-2psi). NB: Your tyres will lose traction if they're filled too much. Ensure the levels are optimal and safe for use.

        • Use main roads and highways: Fewer stops = more mileage. Also, studies have shown that the efficient cruising speed is 70-80km/h; I.E. It's a myth that you get more mileage for more speed. Increasing speed = increasing road resistance and wind resistance = more power needed from engine.

        • Scan ahead: I seriously don't understand why people accelerate only finding themselves hard braking after a couple seconds; it's all wasted energy! If you see traffic slowing down, ease off the pedal. If you see cars stopped at an intersection, ease of the pedal and let the car come to a rolling stop. If you're approaching a corner, slow down at a gradual pace.

        Do all of the above and you will see yourself achieving the best mileage yet!

        • _Bruce_ on 04/10/2013 - 11:22
          +3

          slix_88: This is the best post here.

          Only clarification I would make on 'scan ahead':

          Don't (always) slow down for a green light. If you know that you won't make it before the red, definately slow down. Many people see a green ahead a slow down because they just assume it will change before they get there. End result is that it does but only because they slowed down in the first place.

        • slix_88 on 04/10/2013 - 11:31
          +1

          Agreed. I believe my point was particularly for the case when cars are stationary at a red light and you anticipate a change to green rather than the converse. It's always safe to travel at the speed limit until it turns amber, which should allow you enough time to either pass or gradually slow down if you know you can't make it through in time.

        • Joysky on 04/10/2013 - 21:06

          What do you mean by "plus you'll be using some fuel. Put the vehicle into the appropriate gear such that the RPM for your vehicle are above the fuel cut-off threshold."? I thought the car would only use fuel if I was stepping on the gas.
          Do you use the OBD bluetooth adapters on ebay for ~$10?

        • slix_88 on 04/10/2013 - 21:44
          +1

          Firstly mind the grammatical errors. It was a rushed post.

          It's the same concept as your vehicle idling whilst stationery; it uses fuel to keep the engine running. When in gear and if the RPM is above the fuel cutoff threshold, it will not use any fuel because gearbox will be turning the engine.

          Mine is a custom build connected to an Android tablet. Depends on the make of your car but the one's or the evolutions could be had for around $150+

        • _Bruce_ on 04/10/2013 - 21:47
          +2

          What do you mean by "plus you'll be using some fuel. Put the vehicle into the appropriate gear such that the RPM for your vehicle are above the fuel cut-off threshold."? I thought the car would only use fuel if I was stepping on the gas.

          There are two situations in which you use fuel:

          1: When you apply the accelerator.

          2: When you do not apply the accelerator, the engine will add fuel to keep the RPMs up, charge the battery, power all the electronics, etc.

          When coasting the energy from the car slowing down drives the motor, which in turn powers everything in the car. This reduces (or eliminates) the need to add petrol to the engine.

        • bigticket on 05/10/2013 - 01:14

          Most engine management systems, in a effort to lower emissions, actually shut off fuel when the manifold has reached a certain vacuum, such as when slowing a car by shifting into a lower gear down a hill.
          Doing this by the way will have a negligent on effect on you fuel consumption.

        • TALLBALLER on 05/10/2013 - 21:48

          i have a vy II berlina 3.8 that i have previously had at trip average of around and under 10L/ and no more than 11.5(allowing for different spreads of urban/hwy) while following this sort of "granny" driving
          But for a while i have been driving more normal-agressiveand i am averaging 12.5-pushing 13.5-14 if i am agressive

          but as for the half full tank i do notiv]ce a big difference i pickup when i have 80-100%% of tank v 20-50% which i 'feel' translates into more fuel wether this is offset py evaporation is debatable

        • cloudy on 06/10/2013 - 09:14

          My 2010 Honda accord likes to cruise around 1500rpms, it's auto. Sometimes when I'm on a long stretch at 60km,I manually tap the gear into5th and mmake it cruise at 1100 rpm, believing it should save fuel at lower revs.

          Would this be right?

        • _Bruce_ on 06/10/2013 - 09:34

          … believing it should save fuel at lower revs. Would this be right?

          Probably not. If you are idling without much AC/whatever on then the biggest load on the engine is the internal engine friction, which is lower with lower RPM, so lower is better.

          When you are actually driving a much bigger factor is moving the car. In this case although the engine friction loss will be less the overall drop in efficiency from running at low RPM will hurt you more.

          It really depends on each motor, and as a general rule the more cylinders the lower the efficient rev point. Also the faster you are going the higher revs become more efficient.

        • altomic on 07/10/2013 - 13:11

          on the freeway I try to stay at least 5 car lengths behind the car in front. especially on the inter-city bypasses. people tend to drive 1 car space behind the car in front and as soon as they car in front braking or slowing then they brake and the car driving one car space behind them brakes, etc etc. combine the delay in reaction times for each vehicle then if there is 5 cars then by the time the 1st car has actually started to accelerate then the last car in still braking. if there were 100 cars driving behind each other with 1 car space in between and the first one thinks "hmm, I'm driving a little fast I'll touch my brakes" then it sets off a chain reaction.

          so all these cars are slowing down, losing momentum, wearing out their brakes, causing other driver to slow down, slowing down the general flow of traffic. then they have to accelerate as the traffic picks up.

          if you're scanning a head and the car 5 car spaces ahead hits their brakes lightly (i.e. there are no stopping cars in front) then you can take your foot off the accelerator. the car infront lightly applying brakes isn't going to be losing much speed. you can coast. if need be then apply your brakes lightly . either way the car behind you should be monitoring the gap between their car and you. they may hit their brakes, they may take their foot off the accelerator. if they hit their brakes then probably the car driving 1 car space behind them will probably hit their brakes and so on and so on.

        • hothed on 10/11/2013 - 15:01

          Work out your fuel usage:
          Look at amount of fuel you put in, divide by KMs travelled on trip meter.
          Then multiply by 100 to go from per 1 km, to per 100 kms.

          Ex:
          60 L / 700 KM * 100 = 8.57L per 100km

  • geek001 on 03/10/2013 - 21:58
    -1

    I am not sure if this helps, but I drive an automatic, when I am going down hill, I put my car in neutral, because there is not point for the engine to idle at 1.5krpm if it can be idle at 1krpm.

    Also, if the traffic lights is red in front, I put it in neutral and let it roll towards the traffic lights. There is a chance that the traffic light will turn green before I get there, so I guess it takes less petrol to reach 60km/h when you already moving than from a complete stop.

    Other things I do, park near the entry of the car park if you are going out the same entrance. Walking takes no petrol at all and it is usually easier to find parking away from the front entrance, save time as well. :)

    Oh and when you are filling up, did you know there is some petrol left in the hose? I usually lift the hose and tip it into my tank as well.

    • keverns on 03/10/2013 - 23:26
      +8

      i think you've taken some misleading info with auto and neutral.

      1. moving to neutral while going downhill isn't going to make a difference in a modern day car. why? because when you are cruising/rolling down, the computer shuts off/lowers the percentage of the injector feeding. thus you are engine braking, you'd still i.e see your 1.5k rpm but there's very little to no fuel being injected.

      2. you're just shortening the life of the clutch shoes when moving in and out of neutral just like manual. its cheaper to change your brake pads than to fix a transmission. though im not saying its going to break down within 50 000kms, but you're just reducing its potential life span that it was built for.

      3. you'd end up using a bit more fuel if you when going from a neutral to drive vice versa. why? when you are in neutral, you're basically telling the computer to open up the injectors again, so that it can inject fuel to the engine so it would not stall.

      otherwise like first replier has said, timing and moving with the flow of the traffic lights when able, minimal stop and start at light, saves on brake pads too ;) no heavy foot and you're saving as much as you possibly could.

      i dont know about parking away from some building entrance, i.e chadstone shopping… you'd be probably saving a few cents for petrol, walking to the front door can be quite some distance while other ozbargainers have taken all the bargains which could save a couple of dollars instead. lol

      • geek001 on 04/10/2013 - 00:25
        -7

        Heh… you are making a few assumptions there buddy. I drive a 2002 Mazda and it has done 185,000kms. I think it is lacking many of the fuel saving logic in its computer, that's why I have me to compensate. :) When my car is going downhill, instead of speeding up, it just gets stuck in the gear that it is in and revs really hard because it is going faster but the gears are not shifting.

        I don't know much about cars, so I can't dispute what you are saying. But let's just say I get the most mileage out of a full tank than any other driver in the house.

        Heh.. point taken about the mall parking. Though if I didn't park further away, I would probably still be driving round looking for a park. So I could be the one taking all the bargains while you are still looking for a park? :)

        • _Bruce_ on 04/10/2013 - 07:22
          +1

          I drive a 2002 Mazda and it has done 185,000kms. I think it is lacking many of the fuel saving logic in its computer, that's why I have me to compensate. :) When my car is going downhill, instead of speeding up, it just gets stuck in the gear that it is in and revs really hard because it is going faster but the gears are not shifting.

          Do NOT put in in neutral to 'save' petrol. When the car revs up from going down a hill the energy gained from going down the hill is turning the motor and even powering all your electronics through the alternator (and charging the battery if needed). Putting it into Neutral is completely the wrong thing to do.

        • Shonky on 04/10/2013 - 08:44

          You car will have EFI so it will shut off fuel when coasting in gear. My old 1988 Commodore even did that. Mileage is irrelevant.

          Engine braking in gear saves on brake pad/rotor wear too. Going down a hill it provides more control over the car too.

          Yes it is clear you don't know much about cars. Sorry.

          Edit: and yes the Op tips will unlikely show any tangible savings.

  • nomoneynoproblems on 03/10/2013 - 22:43
    +7

    Lol those tips are for the tightest of the arses. Like many others have said the way you drive will help fuel economy. Main points from me are;

    • Reducing weight. Get rid of unnecessary stuff out of the car. If you want to get the most out of your tank consider removing the jack, spare tire, etc.
    • Optimum tyre pressure. Maintaining this ensures that not only will the car perform better but it will remove the unnecessary drag of an uninflated tyre.
    • If you want to go that extra tight arse mile consider tail gating trucks on the freeway so you enter the slip stream. (don't blame me if you rear end a truck however)
    • and obviously fill up at the cheapest price.
    • Shonky on 04/10/2013 - 08:46
      +1

      These tips are by far the most realistic and will make a noticeable difference although I do not condone tailgating.

    • cloudy on 04/10/2013 - 10:07
      +1

      oh yes, i forgot to mention those things. Reducing unnecessary weight and having tyre pressures suited to your driving is important. Please note i said to ones style, over inflating tyres just a little than recommended i feel like is good idea if most of ur driving is straight on freeways.

      I'm unsure how much slipstream savings can actually be obtained, although the logic does make sense.

      • _Bruce_ on 04/10/2013 - 10:26
        +2

        I'm unsure how much slipstream savings can actually be obtained, although the logic does make sense.

        It's pretty significant over a long distance (ie: interstate). You also get the benifit (though not as much) by just driving normally behind the truck without tailgaiting.

        The downside is trucks kick up a lot of small debris from the road, increases wear and changes of chips on the front of your car (windscreen in particular).

      • May4th on 04/10/2013 - 18:38

        do people really do this? i would have thought risking a big insurance premium hike when you tailend the truck/endangering your and the passenger's life in the process would be enough of a turn-off

        • _Bruce_ on 04/10/2013 - 21:48

          Like I said you don't have to get too close. Normally a car will pull up much faster than a truck, cutting trucks off is far worse.

        • altomic on 05/10/2013 - 19:46

          i use to slip stream when I was young. remember cruising up the Hume from melbourne doing 115kmph and the engine sitting on 2000RPM

    • Matt P on 07/10/2013 - 20:01
      +1

      anyone who ghosts/tailgates trucks to save fuel deserves to be where they end up… under the rigs rear wheels

  • illumination on 04/10/2013 - 01:07

    Lol in response to #3 - I've heard that you should only fill when you're empty and you shouldn't pump full because you "waste petrol carrying petrol". I do think it would be negligible but just sounds funny.

    • _Bruce_ on 04/10/2013 - 07:24

      This is a good point and will surely make more difference than evaporation (unless you car is super heavy anyway).

  • zambuck on 04/10/2013 - 07:29
    +2

    Regarding filling up at the cheapest price, and given that NSW prices at least are up and down like a mad woman's skirts, does anyone else use jerry cans to stock up when prices are low, and therefore ride out some of the extended price hikes? I'm sure there'd be a small amount of loss due to evaporation, however saving 10c/litre or more seems worthwhile.

    Oh and time that with one of the 16c or 20c Woolies vouchers, and pay with 5%-off Wish gift cards, and you're really getting value from your shopping dollar.

    • Austin 316 on 04/10/2013 - 07:53

      I just saw a couple of blokes filling their car and the jerky cans recently while I was at the fuel station. I was thinking why are they doing this when I couldn't see they had any trailers or didn't look like they were going on long trips….

      Now I know they were stocking up :)

      • MementoMori on 04/10/2013 - 10:40
        +1

        Hmmmm… cannned jerky

    • retiredfeline on 04/10/2013 - 09:23
      -1

      Euuw, I certainly don't want to be breathing in hydrocarbon fumes from decanting. No thanks.

  • aldog on 04/10/2013 - 07:39
    +2

    And remember to use your ING card (if you've still got one) and vouchers.
    However, if you're stuck with using cash only, remember to go 2 cents over your total :)

  • nsg on 04/10/2013 - 09:33

    And drive with your windows up.
    Reduces wind drag, and keeps the car clean…

    • _Bruce_ on 04/10/2013 - 09:54
      +1

      Unless the windows are down as an alternative to AC, which will use a lot of fuel. At freeway speeds I'm not sure what will be better (will depend a lot on the car) but any slower than this windows will save more than AC on.

      On that note, if you use climate control with your AC set the temperature a few degrees higher.

      • twodollah on 04/10/2013 - 11:01

        At 80km/hr AC will use less energy than the drag caused to the car.

        • _Bruce_ on 04/10/2013 - 11:17

          Absolute drag definately, but the change from the windows being down? This will depend a lot on the individual car.

  • Shonky on 04/10/2013 - 10:30

    Mythbusters showed AC on, windows up was worse than AC off, windows down but that was only at 72km/h. At 100km/h it's more likely to become lineball plus it's more comfortable. Again that's incredibly tight arse to save some $s but I guess that's the ozbargain way?

    Of course that's a specific car (a great big SUV from memory) and specific situations etc.

  • Darron65 on 04/10/2013 - 10:41
    +7

    On my commute I see a lot of people in front of me accelerating like mad, then braking, then back on it etc. I can peacefully follow them with light acceleration and simply lift when I need a slight slow-down. What do you know, we all stop at the same traffic lights. My Camry only uses 8.3L/100km.

  • bahgain on 04/10/2013 - 11:04
    +5

    I love ozbargain.

  • Giraffe on 04/10/2013 - 11:37
    +1

    I use this website to know when petrol will be cheapest: http://www.accc.gov.au/consumers/petrol-diesel-and-lpg/recen…

    And if I have time to look for the absolute cheapest in my area: http://motormouth.com.au/

  • Dealayed on 04/10/2013 - 12:24

    I read the exact same article a few weeks ago and have been following Tip no 2. It doesnt work. I think i might even have got less fuel than what i paid for.

  • frewer on 04/10/2013 - 12:29

    Those are nice tip from opt. Or you can get one of these car

  • m0nkeycheese on 04/10/2013 - 13:25

    Waste of time IMO

  • retiredfeline on 04/10/2013 - 13:59
    +1

    Looks like your tips came from here:

    http://urbanlegends.about.com/od/automobiles/a/pumping_gas.h…

    About 1, if it makes a difference at all, the best time would be some time after the air temperature low because of the thermal inertia of the petrol.

  • dirtybird on 04/10/2013 - 14:19

    I found I could save fuel if I didnt completely fill my mower when ever I bothered to use it.
    The evaporation in those things is incredible.
    I put enough in to just cover the bottom of the tank and thats it.

  • PissLUR on 04/10/2013 - 19:27

    lucky I live in WA.

    only buy fuel on wednesday. it is the cheapest.

  • KangarooOz on 04/10/2013 - 22:50

    If you can get Wish gift card for 5% off, you would save 7c per litre without the fuel voucher (assume $1.40 per litre) at the Woolworths Petrol station. BTW, you can use the fuel voucher and gift card together (that is, about 11c)

  • dddp on 04/10/2013 - 22:52

    All of these 'tips' are untrue

    1, the fuel volume is measured and verified as being accurate - temperature has no effect. A liter is a liter no matter the temperature of it

    2, there is no vapor return line on AU petrol bowsers

    3, Fuel systems are sealed, vapors can not escape the fuel tank in any meaningful amount

    • Ughhh on 04/10/2013 - 22:57
      +1

      Tip #1 is true I'm pretty sure, I remember my physics lecturer stating this and explaining why.

    • bigticket on 05/10/2013 - 01:39
      +2

      Tip #1. True a litre is a litre, but the difference is that the density changes at different temperatures. At lower temperatures 1 litre weighs more!

      Or another way to look at it-
      1. buy 1 liter at midday
      2. bring it home and put it in the fridge for 1hr. Presto you have slightly less than 1 liter.

  • YTW on 04/10/2013 - 23:07
    +6

    Haha…love all this discussion.

    The main thing I've taken away is that I need to reduce the weight in the car…so hubby and I need to go on diets - for fuel economy of course. Less grocery costs and less fuel costs…lose weight the OzBargain way!

    • bich.light on 05/10/2013 - 23:07

      Or you could just leave Earth, like to space.
      You'd lose a lot of weight! =]

  • DarwinBoy on 06/10/2013 - 00:34
    +1

    I bought a postie bike. Cheaper then any car fuel wise and after 2 years and 14000km it has paid for itself if i did those kilometres in the 4wd.

    • BluebirdV on 06/10/2013 - 14:18

      I got Honda CB125e. Great on fuel. You guys are lucky up there in NT as I understand it only costs $100 a year to register small bikes.

      • DarwinBoy on 07/10/2013 - 12:22

        Yeah. Bout $120 for the postie. Goes up preety quick for the big bikes though. More expensive to register a 650cc then a 4 cyclinder diesel 4wd

  • lameturd on 06/10/2013 - 11:12
    -3

    I think….

    potato

  • Lucky13 on 06/10/2013 - 14:56

    Neutral down hills maybe, but then if you have an accident wont be a saving :(

    • Medrad on 11/10/2013 - 15:15

      Putting the car in neutral doesn't save petrol, infact can burn more. Most cars when on zero throttle and moving will put next to zero fuel into the engine because the current motion of the engine keeps is moving around. If you put it in neutral, the motion from the road isn't there and the pump puts fuel into the engine to keep it "idling".

      So, if you're in an auto car, driving on neutral is a waste of fuel. If you're in a manual, it does the same thing, just less electronics to monitor it.

      Accidents are the big issue… save yourself 2c a month and risk yourself… your choice.

  • airzone on 07/10/2013 - 15:12
    -3

    I was pretty sure the easiest way to save on fuel costs was with a syphon and something to jimmy open fuel caps…

  • Donavann on 09/11/2013 - 05:20

    Well if the traffic light is red at the front side i put it in fairly neutral, and let it move towards the traffic light. There is a opportunity that the traffic light will convert green before i get there so i think it requires, less fuel to achieve 40km/h when you already shifting than from a complete stop.

    • _Bruce_ on 09/11/2013 - 08:41

      Slowing down early is good, putting the car in neutral is not. Try reading some of the comments already provided.

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