Low MPG in Winter

[guest1597]

Hi people

Can anyone tell me please why you get low MPG in Winter? I used to get about 42/43 MPG in summer now i get 37mpg. I have Changed oil filter/pollen filter/K&N air filter\ngk spark plugs and put new carlube 5w-40 oil. My cars only done 53K.

thks

[culzean]

You get low mpg because the weather is colder, this means the air is thicker (more wind resistance) it's colder (needs more petrol mixed with it) and you have headlights and heated windows / mirrors and wipers on a lot more.

I normally get about 55mpg in summer, but only about 45mpg in winter - my driving style is the same, the only thing that has changed is the temperature.

[guest1809]

Hi everyone, this is my first post on this forum. i live in belgium so please do not mind my bad english.
I've bought my jazz 1.4 (2005 - 65000 miles)two weeks ago and it's a great car, and i love it. However there is one huge dissapointement and that's the MPG that i got in the past two weeks. It's been cold here (-2°c) and i do alot short distance trips which influence the MPG but i have never expected that it would have (accoring the bord computer) an average of 10 L / 100 KM which is equal to 28 mpg.

i drive it calm when the engine is cold, i don't turn the airco on, my tires are 2.3 bar.

Previous owner( first owner) went with it to official honda dealer for maintenace and i have all the maintenance history in the book.

what is wrong with my jazz?

[culzean]

Most cars, especially petrol engines only do about 20mpg until they are at full operating temperature, which is why short trips in cold weather are bad on fuel.

Since cars have been fitted with mpg readouts we all seem to have become anoraks about mpg (the high price of fuel doesn't help either) - before we had these displays we just kept filling the tank up when it needed it and probably only did mpg comparisons when we went on long holiday trips once a year.

There is probably not a lot wrong with your Jazz, I commute about 50 miles every day on good roads in the UK (yes, I know it's a surprise but some of our roads are OK) and in the cold weather we are having my mpg is down to low 40 mpg, in summer on the same journey I can get almost 60mpg.

[dogbiscuit]

I used to get about 42/43 MPG in summer now i get 37mpg.

Since 1993 I have been keeping records of every gallon of petrol I have put in my various cars. Regarding my two manual Jazz 1.4 i-DSIs, I averaged 45 mpg over a period of 7 years and 88K miles for both cars. Looking at the graph of fuel consumption I would say I was getting on average 42 mpg over the winter months and 48 mpg in summer. So I would say the 5 to 6 mpg difference you are seeing is not unusual.

[guest1597]

Thanks people for your quick replys- i thought my engine was screwed - 

[guest1262]

Just back from a round trip to Cornwall. Temperature on Dartmoor -5ºC. Perhaps 50% of the whole journey above freezing. Computed average 46.8 mpg over 850 miles.

[guest869]

That makes me feel better. I have been struggling to get an indicated 48mpg recently on journeys where I would expect 50+ mpg. I do have winter tyres and put it down to the extra drag.

It is probably the drag of the tyres in the snow and the cold.

[guest1387]

If you let the car warm up for about 5 mins so the air box can heat up, it does make a difference.
I have a scan gauge fitted to my car, because i want to know how warm the engine is not just a stupid light.

If i let the car warm up for a min or so then drive off the air intake temp stays fairly low, but if i let it warm up longer the air temp stays a little higher.

What winter tyres do you have fitted John?

Ive got some Avon CR85 in 195/50/15 they havent let me down yet and we had about18" one day.

[Berisford]

Ive got some Avon CR85 in 195/50/15 they havent let me down yet and we had about18" one day.

Crikey, 18" and still going, I'll have to get some of them. 

[guest1387]

The front bumper makes a good snow plough, as ive lowered it 35mm

I do 80+ miles a day in the Jazz, daily trip from Wakefield to Skipton, the week we had the snow i got to work every day no problems at all. The winter tyres are excellent and everyone should consider fitting them.

[guest1597]

Hi what sort of springs you got?

Thanks