Cold Weather And Low Mpg?

[Mr Jones]

Drove down to London today, filled up before I drove back and noticed a drop in my MPG! I initially thought it was my tyres pressure but it's fine. Does anyone noticed a drop recently?

I am just over 2200 miles now since new and my mpg still yet to hit pass 55mpg, from driving like an oap to light footing. This is hard!

[s44gtw]

In the simplest form of an explanation ,

cold ambient temperatures in the UK should not increase the fuel consumption in the UK winter.

say a drop to an ambient temp of 1 degrees celsius.

Cooler air means more oxygen and the engine should run smoother,

just like fitting an induction kit.

MAF sorts the fuel, no more should be used.

Short journeys & it takes longer to warm Fluids and to get to running temperature.

More fuel may be used.

**But, when cold you let your car warm up, use heated mirrors, wipers, heated rear screen, Heater/Air Con, lights, radio all on more often,

winter equipment carried in the car, equals more weigh, more load & load on the Battery, alternator runs more..**

More fuel used.

In the cold you might slow down.

Less fuel used.

Winter quality petrol, slightly higher than the Minimum quality & octane of summer fuel.

(runs more efficiently)

Less fuel used.

Cold road surfaces, less grip/friction/traction.

Less fuel used.

Winter tyres fitted, improved traction.

More fuel used possibly.

swings and roundabouts.

Check tyre pressures the way you need to in cold weather.

http://www.michelin....ld-weather-tips

Swings and roundabouts.

george

[Cyker]

This is mostly normal; Just be glad you aren't in a hybrid or diesel engine - It hits us harder

It's all down to the cold - Colder air = denser air and most petrol engines run at a fixed air/fuel ratio so they add fuel to balance the mixture out. (Not to mention the choke kicking in which also makes it run richer and burns more fuel.).

Then there's the engine block - Colder so it saps more energy from the combustion, at least until it warms up, but then the radiator is also wasting heat. This is horrendous with diesel as diesel engines need to be hot to work - Doing short journeys in a diesel engine in winter can slash the mpg in half easily (Hence why you see Taxi drivers with To Let signs and the like wedged over their radiator grills! ).

I'm not sure if petrol is changed in winter; I know the diesel mix is changed in winter to stop it gelling up and to make starting easier, but I wouldn't have thought that would apply to petrol...?

Also, I wouldn't bother driving too gently, at least until the engine warms up. Driving gently will mean the engine takes longer to get to optimal operating temperature - Just drive normally TBH. (Obviously don't rag the engine either; While that will warm the engine up much faster, the oil won't be protecting the engine as well as it would normally so you get increased wear, shortened life etc.)

[atkiman]

over the 2 years or so and 35k miles i've put on it ,i estimate there's about a 2-3 mpg differance in mpg summer to winter. it's normal, apart from anything else you're running more electrics in winter, lights/ heater etc. make sure the a/c is off when running demister or climate control, that'll help.

My RAV is exactly the same 33/34 mpg summer 30/32 winter, I've logged that one over 135k miles and 9 1/2 years.

tony

[DFish]

I've also been suffering poor MPG for about a month, so as I've only recently had an intermediate service. So I thought I'd check the plugs and air filter, and here's what I found.

The plugs look ok.

The air filter however was a different story. I think this should have been changed... What do you guys think?

Fish

[Guest]

I agree about the MPG difference between Summer (what is that again?) and Winter. It makes a lot of sense. Dan, I thought the same thing when I took my air filter out after its service, and then I was informed by informed people on here that it was the schedule of changing the filter at 3 year intervals (I think that was the information I got) even though that was surely its third service -according to the book it is, so that should have been changed surely? However, I have thought about changing mine early, but then I thought about the next service. Will it be changed then? What IF I get a new filter, fit it, and then at the next service they remove it and put in another new one and charge me for it? As long as I remember (tall order) to tell them of course, it wouldn't be a problem, but... I dunno. Also, would I see such a change in the car, with mpg, running better, etc.?

[DFish]

I think for the cost of £10 I'd rather replace than leave like that.

Fish

[Rob1769]

Still dizzzapointed with my 1.33 iQ3 Im driving with slippers on and struggling to get 42mpg! only got 1600 miles on it but was expecting a greater mpg!

[Soeley]

Have you tried taking it to a different dealer to get it looked at?

[DFish]

One thing to remember is that new engines take a while to 'break-in' and get the better MPG or power, depending on how it's run in.

Fish

[aaronfife]

I had the same problem in regards to the air filter. 21,000miles and it looked the same as you've pictured. Toyota told me it was fine. I just bought another fresh one.

You'll always get poor mpg remember as soon as you service it. Wasn't until 500miles or more until my mpg returned to it's usual 60mpg from a tank. Got to remember to that cold winter start ups aren't doing the car any favours. Think how much it struggles to get up to operating temperature in winter. Takes mine a extra 5mins compared to winter :(

[atkiman]

Still dizzzapointed with my 1.33 iQ3 Im driving with slippers on and struggling to get 42mpg! only got 1600 miles on it but was expecting a greater mpg!

What sort of journeys are you doing with it ? local /urban or dual carriageway/m-way ?

if i just use mine mostly around town and a bit of local stuff etc mpg does drop to 47-48 ish. I've just filled up after 2 days of the usual 92 mls round trip on the a14 + m6 with a couple of days of running around locally and got 50 mpg dead.

[Mr Jones]

Still dizzzapointed with my 1.33 iQ3 Im driving with slippers on and struggling to get 42mpg! only got 1600 miles on it but was expecting a greater mpg!

What sort of journeys are you doing with it ? local /urban or dual carriageway/m-way ?

if i just use mine mostly around town and a bit of local stuff etc mpg does drop to 47-48 ish. I've just filled up after 2 days of the usual 92 mls round trip on the a14 + m6 with a couple of days of running around locally and got 50 mpg dead.

I get that on a 1.0!

How many miles does it takes to break in a new engine? The dealer assured me there is no need for a break in but I still took it slow and steady for the first 1000, 2000 miles in, I've seen improvement but then dropped lower than average 50 to 55mpg when I drop down London via the A1(M) from West Yorkshire.

Seeing a lot of us on the forum getting pass 60mpg, I am a little worried... I completely changed my driving style since I got this car, slower and steadier.

[tarquin]

Rob is it multidrive

David

[atkiman]

when i first had this motor , i used to trundle along the A14/M6 at around 55/60 mph , but it wasn't totally happy at that kind of speed with the tall gearing ,and the fuel returns were around 49/51. I now at run at around the 65 mark , with the occasional blitz up to 80ish for the last bit of M6 up to jnc 3.

It's definitely happier running at the higher speed and it seems to reflect in better fuel figures,

[Rob1769]

I woud say a bit of everything, re the journey types also been keeping a fuel log of what I get (mpg) as to where I have filled up, there is a gang of us at work that all have just bought 'dilly cars' and are having a bit of a compo as to who gets what and whats best!! 2 guys are running 10 yr old Fiat *hittyshentos and are pulling 55+mpg! Have been finding im getting more mpg filling up with Tesco rather than 2p/litre cheaper garage down theroad... wierd huh!

David, 1.33 manual

[DFish]

With most of my driving being town/London stop/start I tend to average around 45-48MPG. I think the best I've seen was around 53/54, never up in the 60's. :( (iQ2)

Since changing the filter/plugs, I've found that when plodding along at around 25-30 MPH I get what feels like a misfire, but then when I hit the 40 zone it's all fine, Strange! I'll re-check that everything is connected properly later.

Fish

[averageuser]

Hi!

I have documented my fill ups and mileage relationship all around a year and found about 10% winter/summer difference in Mpg for my vehicle. Since I used Microsoft Excel book, it was easy by mathematical means find core difference in winter/summer deviation in MPG. Firstly, behaviour of our vehicles are governed by ECU, it sets safe corridors of operations for engine and automatic drive. For example when engine and transaxle is below of operational temp. ECU restricts as engine revolutions as gear box gear changing pattern. I live in city where average January temperature is 3 degrees of Celsius. In winter 4-th gear is allowed about 10 minutes since beginning of motion, in summer almost immediately. Count cold start losses, all vehicle lubricant viscosity increase, less ambient light and as consequence wider use of headlights, add here cabin warming, defoggers, all these draws electrical powers which translates into fuel. Below is excerpt from my fuel book, L/100km imp.mpg interconversion chart is included:

https://www.dropbox....ealworldMPG.GIF

Extrapolated fuel efficiency:

https://www.dropbox.com/s/ieq5thu3sh1r9qy/VITZ.YARIS%20MPG.gif

[s44gtw]

Is your 1.0 Vitz Automatic the same as a Yaris?

The 1.0 & 1.3 iQ Multidrive is different in that it is not restricted in the selection of the CVT gearbox at low temperatures before the

coolant and engine oil rises to normal running temperature.

george

[averageuser]

Hello Sir!

My Vitz is genuine car from Japan, purchased as used, 2 years ago with 60 000 miles on odometer, automatic with torque converter e.g. old fashion hydro-transformer, but very reliable. If you interested in mpg, I have some useful information on request s'il vous plaît :

My Vitz in Japan, it's specs:

https://www.dropbox....8lo/my vitz.pdf

Different automatics' comparison:

https://www.dropbox..../AMT vs CVT.pdf

[tonyishuk]

Still dizzzapointed with my 1.33 iQ3 Im driving with slippers on and struggling to get 42mpg! only got 1600 miles on it but was expecting a greater mpg!

Gets slightly better when you get a few more miles on the clock, but that said our IQ3 CVT turns in about the same mpg.

With the CVT, you can feather back the throttle and "feel" the gearbox pick up the torque, and accelarate using the torque. If you flat foot the engine, it just spins up uses more fuel and you get there no quicker.

If its Manual, obviously does not apply

Rgds

[Rob1769]

Done a 450 mile rount trip down to Wales to see my youngest @ Uni, 'caned it' all the way down and got 45mpg/// drove like a pensioner all the way back got 50mpg... so not so bad but still not very impressed!!

[Mr Jones]

Roberto, I've pretty much got the same when I did my London trip last weekend on a 1.0 - all the more unimpressed. My work colleague mentioned getting the first 3 to 5 thousand miles was poor and then it got better as the parts 'losen up'.

Any truth in that?

[atkiman]

i tried driving my iq3 at lower speeds in the 50/55 mph range when i first had it , problem is it has no low down grunt , you have to keep dropping gears to keep it going, even on the slightest slope, result , thought i'd dropped a right clanger buying it because the mpg was nothing to write home about, high 40's most of the time. upping the speed by 10 mph gets enough power to cruise along without keep changing down (ignoring the stupid idiot gear change light), result , happy me and 50 - 55 mpg most of the time.

round my way Shell and tescos are the same price, so Shell it is 90% of the time.

i used to fill up at tesco's when i worked in northampton and could never get the mpg to equal a tank of Shell,i did fill the iq with esso the other week and got 58 mpg out of it.

i would have expected a lincolnshire- south wales r/trip to have returned roughly 52 mpg , but given the weather yesterday 50 mpg was probably a good result

[Heathie]

Hi, My mpg stays pretty good all year round, I average 68mpg in Summer and it tends to drop to around 62mpg in Winter. I have changed my Air Filter twice now, you can get them from German Swedish for £12.99 inc postage. They have a shop on eBay too.