Right.... help appreciated.
I've had my A3 2.0TDI for about 3 months now, not done many miles (2,000) in it, but it's had a couple of good blasts. Now, according to my reckoning, if diesel is 89.9 pence per litre, and I am getting roughly 90 miles to a tenner.... doesn't that mean I am only getting 30mpg?
If so, I should have gone for the petrol!!!!!!
Cue people telling me I am getting 45mpg and it's a good job I did languages at Uni and not Maths.
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I make it 36.7 MPG. Still not very good though.
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I bow to your superior maths, and yes it isn't very good!!! I think I might get it checked out. I haven't even been caning it, the DSG has made me drive like a pensioner..... the onboard computer says it's averaging 45.9mpg. Shome mishtake shurely?
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This isn't maths, it's merely mental arithmetic. Junior school stuff!
9 miles per £ and 0.9 £ per litre = 8.1 miles per litre. Divide by 0.22 = 37 mpg.
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L\'escargot.
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Thanks l'escargot!!! I feel even worse about my mental "agility" than I did before. : )
Seriously, that isn't very good is it? I think it's a stick shift old-fashioned 1.9 PD next! I got a genuine 52 out of my Fabia vRS.
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It's a waste of time trying to calculate the average fuel consumption on the basis of the amount you put in at one fill-up ~ there are too may inaccuracies. Log every fill-up (and the corresponding odometer readings) for a period of a month and then do the calculation. Even then it will vary from month to month depending on the type of driving, the type of journeys, and the weather.
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L\'escargot.
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It's a waste of time trying to calculate the average fuel consumption on the basis of the amount you put in at one fill-up ~ there are too may inaccuracies. Log every fill-up (and the corresponding odometer readings) for a period of a month and then do the calculation. Even then it will vary from month to month depending on the type of driving, the type of journeys, and the weather. -- L\'escargot.
The Snail is right, of course. I've tended to base my judgments on new cars' mpg from serial fillings, but it soon gets boring...
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"90 miles to a tenner" sounds like you are using a very crude method of measuring fuel used. Fill her right up, drive 00s of miles, fill her up again and then do the math - litres to gallons and then divide that into the number of miles.
Then report back here.
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Hey Mad Maxy... when I mentioned education, I didn't want to go back there!!! : ) Only joking.. you're right... just wanted to be sure I wasn't missing something obvious.
I will fill up and report back to class when I have emptied the tank.
Oy, you at the back!! Come on.... if it's that good, share it with the whole class.
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Thanks for helping me with my crude maths, everyone.
I am going to do the far more accurate brim-to-brim reading and see just how bad, or good, it is.
Am going on a blast around North Wales on Saturday, so will be a good start to the test...
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... "90 miles to a tenner" sounds like you are using a very crude method ..
agreed, especially as we all know that in the last 3 months, while stevied was using his new car, the price of diesel has not been constant at 89p as he assumes but has been as high as £1 or more a litre.
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Your miles to £10 method is the fault. Your gauge will most likely be slowly creeping towards full I would think. Albeit imperceptibly. Fill the tank to the top and see how long it goes. I have logged every tank in my A3 2.0TDI since new (now on 32000 miles) and the lowest I've seen is 38mpg when hammered around town. Best I've seen is 64mpg on a long trip of 500 miles straight.
For the record last tank I got 52.1mpg and the computer told me 55.2mpg (just filled up) so figure the computer is about 3mph optimistic.
Overall since new I've had 46.1mpg from it, with early tanks being in the low 40s for MPG (which seems to correlate with what your computer says when adjusted) and then it started picking up from about 4000 miles. I drive as hard now if not harder than I did then.
Enjoy the car, it's lovely. Oh and to get the same power from a petrol you'd have needed the 2.0T FSI - the 2.0FSI without a turbo is way slower, and driven to keep up with the 2.0TDI a T FSI won't get you even 35mpg.
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A good idea when buying fuel is to ask for a receipt. This will show the exact amount of fuel dispensed. You can also use it to note the odometer if you brim the tank.
So brim your tank and note the odometer, ignore the amount of fuel bought. Remember to get a receipt every time you get fuel and add it to any previous receipts. Once you have a number of receipts brim the tank again and note the mileage.
The maths is simple, you need the difference between odometer readings and the total litres purchased. To convert litres to gallons divide by 4.54609188. The divide the mileage by the gallons equals you mpg. You could set a simple speadsheet to do this.
A useful site for all conversation tables is:
www.sengpielaudio.com/Calculations03.htm
Hope this helps.
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Roger
I read frequently, but only post when I have something useful to say.
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Maybe its because its so new and perhaps a little *tight* ?
I have a Fiat Punto van with the 1.3 multijet Diesel engine.
When new it was averaging 57 mpg.
Last Sunday (at 6,000 miles)
It did 72.3 mpg on a run up and down the A1
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The maths is simple, you need the difference between odometer readings and the total litres purchased. To convert litres to gallons divide by 4.54609188. The divide the mileage by the gallons equals you mpg.
You don't need a conversion factor correct to 8 places of decimals!
You're measuring distance in miles and buying petrol in litres, so calculate miles per litre and then divide by 0.22.
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L\'escargot.
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Ok ............... diesel (!) in litres.
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L\'escargot.
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I've found the best way is to wait for the low fuel warning, put in a fixed amount of fuel then see how long it is before the low fuel warning goes again. My A3 does about 40 mpg on the trip to work - 7 miles each way in heavy urban traffic, but on a recent trip to Norfolk from brim fill up to low fuel warning it did 540 miles which is over 50 mpg, this is after 27,000 miles. A colleague with a Toledo 2.0TDi is getting similar figures.
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The low fuel warning light on most cars is activated by the float level - and often the floats are not central inside the tank. A long wide bend in the correct direction will activate the warning light earlier than if cruising at a steady speed in a straight line.
a) wait for the engine to loosen and b) take an average of five or more fill ups brim to brim using recorded mileage.
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"a) wait for the engine to loosen and b) take an average of five or more fill ups brim to brim using recorded mileage."
No need to brim to brim - even that can be inaccurate as brim depends on whether vehicle is on slope/flat/which way slope is etc.
Most accurate way is record mileage and fill to brim and record all fuel purchased. Then after a period fill up at same station to brim: calculate miles and fuel used and .. calculate.
This is the only way - short of metering - I know of getting a accurate measure...
madf
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I used to enter it all in a log book: but it was always above 50mpg in the Audi 80, and sometimes above 60, and at typical Mway speeds (not the fastest in the conga, but brisk) so I didn't bother any more until I got a petrol Golf 2.0. Had to drive well under 70 to get 40mpg, on same Mway journey.....
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Blimey Charlie!
Come back to this today to see all these entries!
Thanks for all your imput. I will do a proper test and hope that as the car loosens I am getting a decent MPG.
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I dunno about all of this.
I can see why you might be interested in the difference between 30mpg or 35mpg.
Personally I wouldn't because the car is going to do what the car is going to do whether I measure it or not. But I don' understand why the difference between [say] 30mpg and 31mpg would matter. And surely if you're worrying about whether or not the car is on a slope that's likely to be the maximum error margin.
I should think the weather, time of day and local terrain makes more difference to your consumption caclulation than that.
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Have the Golf 2.0TDI DSG - long-term average (25,000km) = 48.9 mpg. Recent motorway/touring 2,500 km trip = 50.7 mpg. In the early days "S" mode can be tempting!
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