Low Temperatures

[RNS]

hello all

i did 195 miles last night the temp got down to around 4/5 ish the mpg seems to have suffered a fair bit also does the lower temps effect the car efficiency to gather power from breaking. only saying that coz the engine came on to charge the Battery its never done that before but i only done 1750 so far.

really i am asking what i experienced is that normal ?

[Grumpy Cabbie]

Answered it a bit more comprehensively in the message I sent you, but would also add that the HV Battery loses its ability to store charge when cold - the lower the temp, the less it can store. This isn't a great problem for us here in the UK but can affect things in Canada at -20c or lower.

What you're saying about the engine coming on is normal. Sitting with the heating on rather than just the a/c, appears to use more power from the HV. Guess its to do with more pumps drawing current?

On this subject, I find that using headlights makes little difference to the HV state of charge, but put your front fogs on as well and the HV will drop noticeably quicker. Also, crawling in traffic in winter with the heating and headlights etc on will reduce the HV quickly, the engine will come on for a few mins and then cut out again. This is all quite normal and still much more efficient than a 'normal' car where the engine would be running all the time.

[RNS]

yer got ur message :)

all is good then... i never had the fog lights on yet not sure how to turn them on ill find out when its fogy i am sure ;)

wish it had heat seats :)

[martswain]

Cold weather makes a considerable difference to MPG.

My journeys to work are not affected by traffic as I work shifts.

Last winter when the temp was regularly below freezing, averaged 48.5 MPG

Best week this summer, 58 MPG.

That is comparing the Prius trip computer readout.

[RNS]

last night the temp was back up to 9/10 and mpg was normal again so now i know what to expect

[johalareewi]

I guess that question will be asked a lot on the forum as those who got their Prius or hybrid Auris in the summer get to experience mpgs in the cold. On cold morning starts, the ICE will run a lot more to warm itself and other things up. You can modify this behaviour by using ECO mode during cold morning starts to increase fuel efficiency.