Gauging gas mileage...
03-01-14, 10:28 PM
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Gauging gas mileage...
What's a reasonable distance to assess your fuel mileage over??
I've been using fuelly.com and so far have tracked 252 KMs (157miles)...
I tend to put small amounts of fuel in as it's over $150 to fill the tank on this car, and I'm always on a tight budget...
Anyway apparently I'm getting 4.3KM/L, or 10.2MPG......
I think that's not very good... That's about 98% city driving, I do perhaps have a slightly heavy right foot, but that seems pretty bad, I'm pretty sure I got better in my 1992 Nissan Skyline Gts-t which was a Turbo 2.0L Straight 6 and I thought that was a gas guzzler but damn this car is thirsty!
Basically it seems I'm using almost twice as much fuel as the 3 ES300's from 92/93 that are being tracked on fuelly... Or does it simply not work trying to track mileage when you only put in 5-20 litres at a time?
So do I simply need to track it over more distance? Must I fill the tank to the top and the run it near empty to get a sensible reading? Or do I need to work out why I'm getting such crappy gas mileage? I really don't think I'm that lead footed as to explain the difference between my car and the 3 ES300's on fuelly with the same engine...
My wheel alignment is good, tyres are inflated to 32psi. New air filter, recent oil & filter change done... Still more maintenance to be done...
I've got spark plugs on the way from the USA... I'm thinking fuel filter needs doing....
Any thoughts?
I've been using fuelly.com and so far have tracked 252 KMs (157miles)...
I tend to put small amounts of fuel in as it's over $150 to fill the tank on this car, and I'm always on a tight budget...
Anyway apparently I'm getting 4.3KM/L, or 10.2MPG......
I think that's not very good... That's about 98% city driving, I do perhaps have a slightly heavy right foot, but that seems pretty bad, I'm pretty sure I got better in my 1992 Nissan Skyline Gts-t which was a Turbo 2.0L Straight 6 and I thought that was a gas guzzler but damn this car is thirsty!
Basically it seems I'm using almost twice as much fuel as the 3 ES300's from 92/93 that are being tracked on fuelly... Or does it simply not work trying to track mileage when you only put in 5-20 litres at a time?
So do I simply need to track it over more distance? Must I fill the tank to the top and the run it near empty to get a sensible reading? Or do I need to work out why I'm getting such crappy gas mileage? I really don't think I'm that lead footed as to explain the difference between my car and the 3 ES300's on fuelly with the same engine...
My wheel alignment is good, tyres are inflated to 32psi. New air filter, recent oil & filter change done... Still more maintenance to be done...
I've got spark plugs on the way from the USA... I'm thinking fuel filter needs doing....
Any thoughts?
Last edited by gtstcactus; 03-01-14 at 10:34 PM.
03-02-14, 01:45 AM
#2
Honestly, I dont think you've got your calculations correct. I'd agree you probably aren't going to be expecting the best gas milage. But how are you doing your calculations? Is your tank completely full, then you let it run down a couple liters and you fill it all the way back up? Or are you on the other end of the scale and fill up a few liters every time your near empty. If you're doing the latter, you won't be getting accurate calculations. With your car I wouldn't doubt there might be a few issues causing this, however, fuel filter, spark plugs, etc would only affect the problem in small amounts (granted that becomes costly over time..) and if they were truly the cause, I'm almost positive you'd trip a code for running too rich.
03-02-14, 02:52 AM
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91 Octane is $2.18/litre I think and 98 is probably $2.28/litre
I remember 10 years back when we were paying 80 odd cents a litre for 95/96 (Premium) then oil prices went through the roof, I'm sure they just didn't bother reducing the price when the price of oil went back down (or maybe it hasn't...???)
I'm certain NZ'ers are getting ripped off big time on fuel prices
Last edited by gtstcactus; 03-02-14 at 03:09 AM.
03-02-14, 03:03 AM
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Honestly, I dont think you've got your calculations correct. I'd agree you probably aren't going to be expecting the best gas milage. But how are you doing your calculations? Is your tank completely full, then you let it run down a couple liters and you fill it all the way back up? Or are you on the other end of the scale and fill up a few liters every time your near empty. If you're doing the latter, you won't be getting accurate calculations. With your car I wouldn't doubt there might be a few issues causing this, however, fuel filter, spark plugs, etc would only affect the problem in small amounts (granted that becomes costly over time..) and if they were truly the cause, I'm almost positive you'd trip a code for running too rich.
Fuelly calculation is 252KMs driven divided by 60.61litres of fuel consumed = 4.2KM/Litre (rounded figure)
03-02-14, 10:00 AM
#6
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The proper way to check your fuel consumption is to full the tank up to the top, until it clicks. Then you know the tank is full. Filling it up part way is doing guess-work and you'll never get a proper reading from looking at the gauge.
Reset the trip odometer, and drive a few hundred km or until your near empty on fuel. A shorter measuring range will be subject to more variance, a longer distance gives a better approximation of average fuel consumption. I can never understand why people like refueling more often for just $10 worth of gas, it wastes more time at the pump. Your still paying for what you drive for, its not "more expensive".
Then refuel the car until its full and clicks again. Record the distance measured and divide by the liters of fuel you put in to get the average fuel consumption in liters per hundred kilometers.
I use this method every tank and its dead accurate according to the fuel consumption read-out on the dash 95% of the time.
For comparison, I get roughly 11L/100km on both of my cars with 90% highway driving.
Reset the trip odometer, and drive a few hundred km or until your near empty on fuel. A shorter measuring range will be subject to more variance, a longer distance gives a better approximation of average fuel consumption. I can never understand why people like refueling more often for just $10 worth of gas, it wastes more time at the pump. Your still paying for what you drive for, its not "more expensive".
Then refuel the car until its full and clicks again. Record the distance measured and divide by the liters of fuel you put in to get the average fuel consumption in liters per hundred kilometers.
I use this method every tank and its dead accurate according to the fuel consumption read-out on the dash 95% of the time.
For comparison, I get roughly 11L/100km on both of my cars with 90% highway driving.
Last edited by speedkar9; 03-02-14 at 10:03 AM.
03-02-14, 10:33 AM
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The proper way to check your fuel consumption is to full the tank up to the top, until it clicks. Then you know the tank is full. Filling it up part way is doing guess-work and you'll never get a proper reading from looking at the gauge.
Reset the trip odometer, and drive a few hundred km or until your near empty on fuel. A shorter measuring range will be subject to more variance, a longer distance gives a better approximation of average fuel consumption. I can never understand why people like refueling more often for just $10 worth of gas, it wastes more time at the pump. Your still paying for what you drive for, its not "more expensive".
Then refuel the car until its full and clicks again. Record the distance measured and divide by the liters of fuel you put in to get the average fuel consumption in liters per hundred kilometers.
I use this method every tank and its dead accurate according to the fuel consumption read-out on the dash 95% of the time.
For comparison, I get roughly 11L/100km on both of my cars with 90% highway driving.
Reset the trip odometer, and drive a few hundred km or until your near empty on fuel. A shorter measuring range will be subject to more variance, a longer distance gives a better approximation of average fuel consumption. I can never understand why people like refueling more often for just $10 worth of gas, it wastes more time at the pump. Your still paying for what you drive for, its not "more expensive".
Then refuel the car until its full and clicks again. Record the distance measured and divide by the liters of fuel you put in to get the average fuel consumption in liters per hundred kilometers.
I use this method every tank and its dead accurate according to the fuel consumption read-out on the dash 95% of the time.
For comparison, I get roughly 11L/100km on both of my cars with 90% highway driving.
I Never said I liked putting smaller amounts of fuel in, I said I put in what I can based on whats going on in my wallet............ I put in what I can afford too...
I still don't understand why using the odometer to monitor distance travelled, and the pump to measure fuel in & a fuel light to determine time to put some fuel in & fuel used won't give an accurate reading. I'm not saying anyone is right or wrong I just don't get it. I would like to "get it" It's been done over 7 tops using the fuel light, so it's got to be reasonably consistent, and not really any different from using the fuel light to determine the fuel is gone after a tank has been full.
I know exactly how much fuel I've put in and consumed (60.61 litres) which is all the fill ups I've done over the last 252KMs and doesn't count my last fill up as I have not used that fuel yet.
Distance driven divided by fuel used is still going to work out the same if you've put 7 or 70 litres in give or take a small amount isn't it????????????
If I was filling it up I'd still be using the same light on the same fuel gauge as my indicator it's time to fill up - so what's the difference??
The injectors don't squirt more fuel because theres less in the tank? The fuel pump doesn't pump more fuel because the tank isn't full The engine doesn't use more fuel because the tank is empty????????
I'd say the fuel pumps at the petrol stations are pretty damn accurate as they wouldn't want to be giving anything away for nothing, or anything more than they have to! There can't be so much fuel in the tank left after the E light comes on that I'd double my mileage, or even added half again.... I usually leave it a little bit after the light comes on to top up too..
Last edited by gtstcactus; 03-02-14 at 11:13 AM.
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03-02-14, 10:08 PM
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Everyone is being ripped off at the pump.
I knew you guys were paying more but I didn't think it was that much more. A tad higher than I would ever like to be paying. I know the dollar difference varies from country to country and so on, but paying that much is ridiculous.
I knew you guys were paying more but I didn't think it was that much more. A tad higher than I would ever like to be paying. I know the dollar difference varies from country to country and so on, but paying that much is ridiculous.
03-03-14, 04:48 AM
#9
Lexus Champion
Fuel gauges are inaccurate, there's so much tolerance in the readings. The fuel light is usually set to come on when the fuel float drops to a certain point in the tank. However these points will differ from tank to tank, especially while driving.
In general, you know the tank is at a measurable and repeatable point when its full and the gas pump clicks. When the empty light comes on however, you don't know if there's 5 or 10 liters left in the tank.
Fuel pumps are usually accurate. Look closely and you'll see a calibration sticker, they have to be re-calibrated every so often.
I still don't understand how it "costs" you more to fill up your tank. You pay for the fuel you use, regardless if its 4 small fill-ups or a tank full.
Last edited by speedkar9; 03-03-14 at 04:53 AM.
03-03-14, 08:06 AM
#10
The idea is to remove the fuel gauge altogether from your mileage calculations.
Fuel gauges are inaccurate, there's so much tolerance in the readings. The fuel light is usually set to come on when the fuel float drops to a certain point in the tank. However these points will differ from tank to tank, especially while driving.
In general, you know the tank is at a measurable and repeatable point when its full and the gas pump clicks. When the empty light comes on however, you don't know if there's 5 or 10 liters left in the tank.
Fuel pumps are usually accurate. Look closely and you'll see a calibration sticker, they have to be re-calibrated every so often.
Statistically speaking, the average over a longer period of time will be more accurate and representative of your average fuel consumption, as opposed to one or two trips (with say 1 cold start in between). I say bite the bullet one day and fill up a full tank, drive it till empty and record your readings.
I still don't understand how it "costs" you more to fill up your tank. You pay for the fuel you use, regardless if its 4 small fill-ups or a tank full.
Fuel gauges are inaccurate, there's so much tolerance in the readings. The fuel light is usually set to come on when the fuel float drops to a certain point in the tank. However these points will differ from tank to tank, especially while driving.
In general, you know the tank is at a measurable and repeatable point when its full and the gas pump clicks. When the empty light comes on however, you don't know if there's 5 or 10 liters left in the tank.
Fuel pumps are usually accurate. Look closely and you'll see a calibration sticker, they have to be re-calibrated every so often.
Statistically speaking, the average over a longer period of time will be more accurate and representative of your average fuel consumption, as opposed to one or two trips (with say 1 cold start in between). I say bite the bullet one day and fill up a full tank, drive it till empty and record your readings.
I still don't understand how it "costs" you more to fill up your tank. You pay for the fuel you use, regardless if its 4 small fill-ups or a tank full.
If you really want to get a handle on your fuel consumption, you need to bite the bullet and fill the thing up, and instead of putting a few gallons in here and there, burn through at least a half tank or so to get a larger sample size to measure. Save up and fill it so you can determine more accurately how much you've used for the miles indicated by the trip odo, the total amount you put in is going to be the same, whether you add 3 gallons 5 times or 15 gallons once. And these things don't "require" premium, at least not here, it is only recommended, and any increase in mpg is going to be more than offset by the increase in fuel cost.
That said, since your miles are 98% city, you'll be lucky to get mid to high teens, and you don't have much room to complain about lousy mileage if you drive with a heavy foot. Practice driving smoothly, both accelerating and braking, and look ahead so you can avoid accelerating or braking unneccesarily. Both pedals burn fuel, the gas pedal obviously feeds fuel to the engine, and every time you brake, you turn that fuel you burned into heat. Smooth driving and coasting when you can instead of braking, when possible, will maximize your economy and save you money.
03-04-14, 10:44 PM
#11
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I usually get around 450km to a full tank mostly town driving.
I'm heavy footed.
Haven't really tried on the open road but i presume only a slight increase in KM.
Seems like temperature wise for the motor really effects how much fuel you do use.
I usually carry a fair amount of tools and all my audio gear in the trunk so that probably doesn't help.
I'm heavy footed.
Haven't really tried on the open road but i presume only a slight increase in KM.
Seems like temperature wise for the motor really effects how much fuel you do use.
I usually carry a fair amount of tools and all my audio gear in the trunk so that probably doesn't help.
03-05-14, 10:53 AM
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I guess I will just have to fill up and see what results that brings....
Sprey, are you from Wellington, NZ?? What fuel do you use? 91, 95/96 or 98?
Sprey, are you from Wellington, NZ?? What fuel do you use? 91, 95/96 or 98?
03-12-14, 12:45 PM
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