Does cold weather affect fuel economy

[lewisy]

I suspect the answer is yes, i do a lot of small distance driving, basically to and from work, 4 miles each way, and i've noticed my economy go from 250 miles to a tank to just under 200 miles!!! please put my mind at rest to tell me the engine is running richer in cold weather and taking longer to warm up hence consuming more fuel and i've not been buying dud fuel..

thanks Lewis

 

[SOates82]

2 ways to look at this... it could be either!

1) Cold air = more dense so the ECU can throw in more fuel to the cylinders to burn as there will be more O2 in there, so you use more fuel

BUT

2) The above case will result in more power produced so you can use less throttle resulting in better economy...

:lol: Hope that helps!

 

[CTR_Paul]

I've noticed mine drop too.

Although that might be partially due to me starting the car for 3 or 4 mins before driving it.

 

[smithers]

colder air = better fuel economy (denser air = less fuel reqd), but cold engine = worse fuel economy, so short runs = worse economy

(generally)

 

[Friendy]

iirc saw on top gear that you get more fuel when it is cold.

 

[SOates82]

colder air = better fuel economy (denser air = less fuel reqd), but cold engine = worse fuel economy, so short runs = worse economy

(generally)

Not quite... Denser air means more fuel is used as there is more O2 going into the motor and so the air mass flow sensor tells the ECU to throw in more fuel to get better combustion.

 

[CTR_Paul]

colder air = better fuel economy (denser air = less fuel reqd), but cold engine = worse fuel economy, so short runs = worse economy

(generally)

Not quite... Denser air means more fuel is used as there is more O2 going into the motor and so the air mass flow sensor tells the ECU to throw in more fuel to get better combustion.

Hence the idea of cold air induction kits !

 

[smithers]

yes, but that means you don't need to put your foot down as hard to get the same level of performance...

then again, doesn't mean to say you don't want to use those few extra ponies :twisted:

 

[paul.goffin]

I think its the car being on choke for longer and therefore running richer for longer periods, waiting for it to warm up.

You will notice this a lot more on short runs to work each day.

 

[SOates82]

I think its the car being on choke for longer and therefore running richer for longer periods, waiting for it to warm up.

You will notice this a lot more on short runs to work each day.

10 points for that man! I haddnt even thought of that

 

[Composite Guru]

Fuel expands with heat so you will find it goes further when its hot and less when cold.

A little fact i was told during my Aeronautical Apprenticeship.........

One of my tutors seemed to know quite a bit about the fuel side of things and he said during the summer fill your car up late at night when the cars tank is at its coolest, this stops the fuel expanding whilst going into the tank giving you more fuel during the day when it's hot. Can make a difference in this day and age. :wink:

This doesn't mean you put half a tank in and it is a full tank by morning!! :lol:

 

[Millsey]

I think its the car being on choke for longer and therefore running richer for longer periods, waiting for it to warm up.

You will notice this a lot more on short runs to work each day.

Exactly mate... People have probably forgot about the manual chokes that used to be around as well... Cars wouldn't even start unless that baby was yanked all the way out.. :lol:

 

[lewisy]

thanks for the replies, feel better now. I generally start my engine and let it sit idling for about 4/5 mins so that the engine warms up a bit, that can't be helping the economy :roll: and apparently it's gonna get colder towards the end of this week!!!

grrreeat :shock:

 

[Trung]

I've noticed my fuel has severally dropped in this cold temperature too :|

 

[Bazzer]

Fuel expands with heat so you will find it goes further when its hot and less when cold.

A little fact i was told during my Aeronautical Apprenticeship.........

One of my tutors seemed to know quite a bit about the fuel side of things and he said during the summer fill your car up late at night when the cars tank is at its coolest, this stops the fuel expanding whilst going into the tank giving you more fuel during the day when it's hot. Can make a difference in this day and age. :wink:

This doesn't mean you put half a tank in and it is a full tank by morning!! :lol:

I was also told to fill up first thing in the morning, last thing at night as you'll get more juice for you money due to the reason aboove :wink:

 

[paul.goffin]

I think its the car being on choke for longer and therefore running richer for longer periods, waiting for it to warm up.

You will notice this a lot more on short runs to work each day.

Exactly mate... People have probably forgot about the manual chokes that used to be around as well... Cars wouldn't even start unless that baby was yanked all the way out.. :lol:

Sometimes I wish you still had a bit of manual control, because I'm sure they run the car on choke too much and for far to long

 

[Chris.]

It's not good for the car to be idleing for so long in the cold. 1 Min MAX then start driving. An increased load on the engine will result in the eninge warming up quicker and reducing consumption.

Leaving it for 5 mins sat at 2k rpm isn't going to do it a world of good economy wise and warming up wise either.

 

[GaryMan]

so thats why i got less fuel economy this week !!

its all make sense now :lol: