Difference between revisions of "Fuel System mpg"
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4.033 galls = 32.264 pints | 4.033 galls = 32.264 pints | ||
If you did this by 'brimming it' (at the same garage parked at the same pump, at the same temperature) you could easily be a pint out, probably more. That's 3% for starters, so anywhere from 38.9 to 41.4 mpg - if you tried very hard to fill exactly to the same point. So even with such a small error as a pint, one will be saying - my car does 40 mpg, and it'll be lucky to do 39, another saying 38 when it could be doing 40 or more. In | If you did this by 'brimming it' (at the same garage parked at the same pump, at the same temperature) you could easily be a pint out, probably more. That's 3% for starters, so anywhere from 38.9 to 41.4 mpg - if you tried very hard to fill exactly to the same point. So even with such a small error as a pint, one will be saying - my car does 40 mpg, and it'll be lucky to do 39, another saying 38 when it could be doing 40 or more. In practice errors are ''larger'' than this. | ||
So if you didn't try hard to re-brim exactly as before nor (at the same garage parked at the same pump, at the same temperature), then we're pissing in the wind | So if you didn't try hard to re-brim exactly as before nor (at the same garage parked at the same pump, at the same temperature), then we're really pissing in the wind (Smilie) | ||
Brim it accurately, and finally at the same pump after a dozen runs like that, logging all the fuel in between, and that would be a good all-round figure - for that journey (and only that journey, with that driver, at that time, and that season) - Winter mpg can be 5-10% less good than summer. | Brim it accurately, and finally at the same pump after a dozen runs like that, logging all the fuel in between, and that would be a good all-round figure - for that journey (and only that journey, with that driver, at that time, and that season) - Winter mpg can be 5-10% less good than summer. | ||
Sorry, rant over, just seen it all and heard it all. The best and incontrovertible way is to log all the fuel you ever fill up with in an Excel spreadsheet and plot the running-mean mpg's - very useful for spotting when the engine's going off, tyre pressures are low, or your boots are full of lead Wink - but only anoraks or obsessives do that (which is how I know you didn't really mean - exactly ) | Sorry, rant over, just seen it all and heard it all. The best and incontrovertible way is to log all the fuel you ever fill up with in an Excel spreadsheet and plot the running-mean mpg's - very useful for spotting when the engine's going off, tyre pressures are low, or your boots are full of lead Wink - but only anoraks or obsessives do that (which is how I know you didn't really mean - exactly ) | ||
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'''Fuel Guage''' dont get caught out, the gauge is non linear, usually. Full to half is more like 3 quarters of a tank half to empty drops like a stone. this may be due to older wiring tank senders etc, but I have noticed a few people mention it. | |||
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Post your figures here: | Post your figures here: | ||
Bob 1.9 petrol hightop camper = 20-23MPG | Bob - 1.9 petrol hightop camper = 20-23MPG | ||
Matt - 1.9 petrol poptop, fully loaded, and I mean fully, inc bike rack and 5 passengers, 14 day road trip = 18 to 20 mpg on LPG | |||
Harry - Diesel 1.9TD (AAZ) Syncro Doka (wiv 15" wheels, knobbly tyres, and running 12 psi boost) = circa 23 mpg | |||
CJ (quote) - If anyone says they're getting more than 20mpg from a 2.1 WBX, be very circumspect about their measurememts or calculations | |||
kevtherev - 18-25......depends how heavy your foot is, reserve ....i.e on red is...2 gallons | |||
Revision as of 07:49, 26 June 2006
Just add petrol and diesel MPG figures here please, LPG figures go in the LPG section.
Clive's Debunking of accurate MPG figures None of the figures are correct for your mpg, because the amount of fuel used over such a short distance cannot be measured accurately, whatever anyone tells you - honest!. Plus there will inaccuracies in the true mileage recorded, and whilst some of these may cancel out, equally they may not, and add exagerrating any errors.
162 miles/ 4.033 galls = 40.165 mpg
4.033 galls = 32.264 pints
If you did this by 'brimming it' (at the same garage parked at the same pump, at the same temperature) you could easily be a pint out, probably more. That's 3% for starters, so anywhere from 38.9 to 41.4 mpg - if you tried very hard to fill exactly to the same point. So even with such a small error as a pint, one will be saying - my car does 40 mpg, and it'll be lucky to do 39, another saying 38 when it could be doing 40 or more. In practice errors are larger than this.
So if you didn't try hard to re-brim exactly as before nor (at the same garage parked at the same pump, at the same temperature), then we're really pissing in the wind (Smilie)
Brim it accurately, and finally at the same pump after a dozen runs like that, logging all the fuel in between, and that would be a good all-round figure - for that journey (and only that journey, with that driver, at that time, and that season) - Winter mpg can be 5-10% less good than summer.
Sorry, rant over, just seen it all and heard it all. The best and incontrovertible way is to log all the fuel you ever fill up with in an Excel spreadsheet and plot the running-mean mpg's - very useful for spotting when the engine's going off, tyre pressures are low, or your boots are full of lead Wink - but only anoraks or obsessives do that (which is how I know you didn't really mean - exactly )
Fuel Guage dont get caught out, the gauge is non linear, usually. Full to half is more like 3 quarters of a tank half to empty drops like a stone. this may be due to older wiring tank senders etc, but I have noticed a few people mention it.
Post your figures here:
Bob - 1.9 petrol hightop camper = 20-23MPG
Matt - 1.9 petrol poptop, fully loaded, and I mean fully, inc bike rack and 5 passengers, 14 day road trip = 18 to 20 mpg on LPG
Harry - Diesel 1.9TD (AAZ) Syncro Doka (wiv 15" wheels, knobbly tyres, and running 12 psi boost) = circa 23 mpg
CJ (quote) - If anyone says they're getting more than 20mpg from a 2.1 WBX, be very circumspect about their measurememts or calculations
kevtherev - 18-25......depends how heavy your foot is, reserve ....i.e on red is...2 gallons
