Ninehigh
|
| posted on 11/1/10 at 02:19 AM |
|
|
Cold weather and fuel
I know cold weather means you use more fuel, by having your demisters and heaters on more etc. But I've noticed over the past few days that
before winter really kicked in I was getting 38-40mpg overall and now I'm barely breaking 30..
I'm just wondering if something like this is about right or should I start checking out those injectors lots of people on here have said will
break at about the mileage I have on the car?
There's been no real change in driving either, apart from the 2 minute wait for the windows to defrost and rolling in 2nd down our road on the
ice. That can't make a 10mpg difference can it?
|
|
|
|
|
ReMan
|
| posted on 11/1/10 at 08:05 AM |
|
|
If your doing short journeys it will really hit it as being so cold at the mo the car will run with the choke on a lot longer (or in the case of
injection) squirt more fuel in
|
|
|
Daddylonglegs
|
| posted on 11/1/10 at 08:22 AM |
|
|
My Peugeot 308 diesel normally averages 58mpg locally to work and back, but in this weather I've barely made 50mpg. I assume it's because
I'm driving like a nanny so I stay on the road? Sooner get to where I'm going at 20mph though than not at all 
JB
It looks like the Midget is winning at the moment......
|
|
|
adithorp
|
| posted on 11/1/10 at 08:43 AM |
|
|
Wait and see is the short answer. If it's just the weather then it'll improve once it warms up. Alternative... start replacing things
(fairly randomly) based on an internet forum diagosis?... 
adrian
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
|
|
|
Bluemoon
|
| posted on 11/1/10 at 09:08 AM |
|
|
Fuel is changed for the winter, they do change the blend.. I doubt this is what has changed your Mpg though..
Dan
|
|
|
smart51
|
| posted on 11/1/10 at 09:53 AM |
|
|
I've recorded the MPG of my main cars for several years. MPG goes up in the summer and down in the winter. I guess a really bad winter will
make it go down even further.
All the reasons stated above. Driving at 15 MPH doesn't help consumption, neither does warming your engine for minutes before driving.
Tickling the throttle (on a petrol) makes your engine run less efficiently. Cold engines run rich until the warm up, which takes longer in cold
weather.
I'd wait until it warms up before worrying.
|
|
|
AdamR
|
| posted on 11/1/10 at 01:29 PM |
|
|
Conversely, on a long journey once your engine is up to temperature and the screens are demisted, you should actually see increased MPG. This is
because cold air is denser causing your engine to produce more power for a given amount of fuel (or the same amount of power for less fuel).
Actually, ignore the above - just worked out that it's a load of cobblers.
[Edited on 11/1/10 by AdamR]
|
|
|
02GF74
|
| posted on 11/1/10 at 02:00 PM |
|
|
quote:
Originally posted by AdamR
Conversely, on a long journey once your engine is up to temperature and the screens are demisted, you should actually see increased MPG. This is
because cold air is denser causing your engine to produce more power for a given amount of fuel (or the same amount of power for less fuel).
Actually, ignore the above - just worked out that it's a load of cobblers.
denser air is a double edged sword - as well as the above, the cars has more mass (i.e. more densely pack air molecules) to push out of the way.
|
|
|
stevebubs
|
| posted on 11/1/10 at 03:04 PM |
|
|
Denser air in theory means you need more fuel to maintain the target AFR.....
|
|
|
AdamR
|
| posted on 11/1/10 at 03:09 PM |
|
|
quote:
Originally posted by stevebubs
Denser air in theory means you need more fuel to maintain the target AFR.....
Yep, absolutely. funnily enough that had never occurred to me until a few seconds after my post!
|
|
|
Ninehigh
|
| posted on 11/1/10 at 07:38 PM |
|
|
No problem, shall wait until it gets warmer. Checking the tyre pressures can't hurt either 
|
|
|
JoelP
|
| posted on 11/1/10 at 07:45 PM |
|
|
cold dense air makes your tyres relatively more flat, so more rolling resistance. As said theres also more mass of air in the car to move about.
|
|
|
irvined
|
| posted on 11/1/10 at 08:26 PM |
|
|
As said its down to the additional fuel used to warm the car up (or having the choke out for longer.)
I also attribute it to the additional antifreeze in the fuel.
I notice normally about 20% difference between peak summer and peak winter, however this year its been closer to 40% drop in economy despite not being
stuck in traffic that much, my care doesn't get properly warm for about 40 minutes to an hour and its just dumping fuel down as part of the warm
up process.
http://irvined.blogspot.com
|
|
|
Angel Acevedo
|
| posted on 12/1/10 at 01:55 AM |
|
|
Gear related Fuel Economy
Another thing that drives Fuel consumption higher is that you spend more time on lower gears therefore more revolutions per mile traveled....
Beware of what you wish.. for it may come true....
|
|
|
