Technical 46 mpg
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Technical 46 mpg
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I have climate, but set it to manual. Ambient 35+, display on 24, A/C on, S/S works fine. If I dip the selected temperature to around 22 (even in manual) the S/S magically stops working. It's a nuisance that you almost need a degree to work out how these cars work.
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Well, the difference is nothing like 4 degrees (although could of course vary), on 44 degree days S/S works with a set temp of about 26-28, but on those days I switch S/S off anyway
There's probably a threshold where it is obvious that the set point will never be reached, so it might as well not bother. That said, is the fan roaring at full speed?
I love how everyone is glossing over the fact that the OP has a Grande Punto and has posted in the wrong section
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I love how everyone is glossing over the fact that the OP has a Grande Punto and has posted in the wrong section
We set our own agenda in these parts
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I love how everyone is glossing over the fact that the OP has a Grande Punto and has posted in the wrong section
Stop talking nonsense, man. There is only the Fiat 500. Nothing else counts.
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That's in manual, so the fan speed is set by the driver, I'm not a big fan of auto mode.
4mpg, 1 mpg, make your mind up!
In the summer it makes no difference to my MPG, just like it doesn't in the winter.
I've run an LPGed Stilo for 55k miles, first 25-30k using AC when it felt was needed, last 25-30k it was on constantly, night and day, regardless of if I wanted hot or cold air. In a car that returned 30-33 MPG I'm sure I'd have noticed this 4 MPG difference and you know what, I didn't as there wasn't one. Even got the stats of all 289 fill ups if you want a gander
Anyone who thinks they can run their A/C without it affecting their mpg is delusional. It takes energy to drive the compressor and that energy has to come from the fuel.
How noticeable the difference will be depends, amongst other things, on how economically you are driving in the first place.
Driving with the windows open also reduces your mpg, so if you drive with the windows open instead, you may see no difference at all. The general rule is that at speeds over 50mph, using the A/C uses less fuel than opening the windows; below 50mph, the opposite is true.
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4mpg, 1 mpg, make your mind up!
I've run an LPGed Stilo for 55k miles, first 25-30k using AC when it felt was needed, last 25-30k it was on constantly, night and day, regardless of if I wanted hot or cold air. In a car that returned 30-33 MPG I'm sure I'd have noticed this 4 MPG difference and you know what, I didn't as there wasn't one. Even got the stats of all 289 fill ups if you want a gander
4MPG with the compressor ON. Zero MPG with the compressor OFF. If you've got climate and the A/C is switched 'ON', the compressor might never actually turn on at all, hence a 0MPG difference. In a cold country, I can see how even leaving the switch 'ON' might not make a measurable difference, since the A/C isn't actually running. You might as well mark the switch 'Rocket Booster' or 'Free Tibet'.
While I will freely admit that 300 fill ups is impressive historical data, it's fairly meaningless unless you've also logged the exact number of hours the compressor was actually running for each fill.
Here's a little set of graphs I found:
http://mcclanahoochie.com/blog/2010/08/idle-fuel-consumption-ac-vs-no-ac/
You'll note that even turning up the fan has a marked effect on GPH. A/C almost doubles idle fuel consumption. Actual real world figures will depend on the actual compressor 'run time'.
Furthermore, your car uses almost double what my TA does, so since A/C consumption is actually measured in GPH not MPG, and MPG is only extrapolated from GPH, your MPG difference A/C on vs off should only be about half of what it is for an eco car like a TA. Perhaps it's worth pointing out that I said MY car uses 4-5MPG extra not YOUR car, nor anyone driving a Cadillac or Refrigerated truck either.
EG: Car 'A' Gets 10MPG, obviously, turning the A/C on isn't going to subtract 4MPG (maybe in a refrigerated truck)
Car 'B' gets 70MPG, turning the A/C on can easily use 4MPG.
But at idle the TA uses 0.6-0.8l/hr, and my 4.0l Jeep reports 0.7-0.9 for it's much more effective A/C, so the L/hr should be pretty similar no matter the car.
Plug in you scan tool and get back to me
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Ok, I badly worded it, yes it'll make a difference. But nothing noticeable, just like having your headlights or rear screen heater on will also affect your MPG, but again not to anything that is normally noticeable.
This may be true but when I am running on fumes I turn everything off in the hope that the car will get to the petrol station without running out.
ahmett
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Even got the stats of all 289 fill ups if you want a gander
Feeling charitable, I took up the invitation. 31.9MPG average, 34MPG last, 41MPG best. 9 MPG between average and best???? Tells me absolutely jack
If every tank returned the same MPG +/- 1-2 then you might have had a point.
Well every tank is not going to give the same is it, but there isn't a 10-15% difference in mpg between AC being on and off as you first advised!
All of these will affect mpg. It's not easy to notice things which make a small difference to economy, because they're masked by journey-to-journey variations in traffic, windspeed & weather. For example, on a round trip at a steady 55mph in a 15mph wind (which is by no means unusual), I'll see about a 10mpg difference in the outbound & return leg trip figures, just because of the effect of the wind. But just because something isn't easily noticeable, doesn't mean it doesn't matter.
I've spent a lot of time over the 3yrs I've had the cars working out how to operate them economically, and I think I've earned the right to talk meaningfully about what does and does not save fuel. The long term mpg figures have always been in my sig, and if anyone thinks they've a better idea about how to ecodrive, they're most welcome to improve on them.
From memory when I did a quick check last year, steady 50mph motorway figures were around 71mpg with the A/C off, 65 mpg with it on, which is about 10%. I haven't tried it, but at 70mph I'd expect the difference to be more like 5%. When the weather warms up, I'll do a few 10 mile controlled runs to see if I can put some harder numbers to this.
The A/C, the lights & the HRW all use fuel. None of these are hugely significant in isolation - not turning on the A/C on a motorway journey from London to Birmingham would barely save you the price of a cup of coffee - but, over time, it all adds up. I always use what I need when the occasion calls for it - after all, I paid for these toys in the first place - but leaving them on unnecessarily is wasteful.
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