Clubjazz - Honda Jazz & HR-V Forums

Honda Jazz Forums => Honda Jazz Mk4 2020 - => Topic started by: jaytee on January 12, 2026, 05:19:30 PM

Title: Winter MPG
Post by: jaytee on January 12, 2026, 05:19:30 PM
Our Crosstar mpg has gone from 60 to 50 approx during the last couple of months, is this just a weather issue, anyone getting same results?
Title: Re: Winter MPG
Post by: JB on January 12, 2026, 05:40:24 PM
My Jazz when new showed m p g at 71 or 72 second year showed m p g at 64 or 68
falling to 57/58 this winter, come this Summer will expect to see 64 again, put it down to
using electric seats steering wheel heater lights,
Title: Re: Winter MPG
Post by: MRCLICKCLICK on January 12, 2026, 06:33:05 PM
same
Title: Re: Winter MPG
Post by: ahavoja on January 12, 2026, 08:53:27 PM
My MPG also goes down during winter. One of the main reasons for this must be the increased need for cabin heating to keep windows free from ice and fog. In cold weather the engine idles for longer to produce the cabin heat, burning more petrol.
Title: Re: Winter MPG
Post by: stani on January 13, 2026, 07:07:14 AM
Dramatic difference. Spring/summer 3.9l. Now in winter 6.8l. It's not only because of the winter season but also because I only drive short distances (https://clubjazz.org/forum/index.php?topic=12364.msg154950#msg154950) in winter now.
Title: Re: Winter MPG
Post by: Nicksey on January 13, 2026, 07:38:39 AM
Yes, same here.
70mpg in summer, down to around 55/60mpg now because of heater/seat and steering wheel heat. I have seen it drop as low as 45mpg in some instances.
Title: Re: Winter MPG
Post by: Kremmen on January 13, 2026, 08:03:19 AM
With the hybrid engine running far more in the winter, the mpg drop will be more noticeable than a ICE car where the engine is running all the time
Title: Re: Winter MPG
Post by: FMIB on January 13, 2026, 08:35:29 AM
Some of my short winter weather trips of 5 or 6 miles have seen consumption down into the low 30's, nothing to worry about.
Most cars, irrespective if its petrol, diesel or EV powered are less efficient in cold weather.
Title: Re: Winter MPG
Post by: Marco1979 on January 13, 2026, 09:04:24 AM
It is also due to higher air density (more air resistance) and stiffer tires (more rolling resistance).
You can limit the consumption by shutting off heating and only using heated seats. But only if visibility is not compromised.
Title: Re: Winter MPG
Post by: aphybrid on January 13, 2026, 09:22:25 AM
See one of main posts - MPG for those interested.

My results on graph clearly shows winter effect and not at all unexpected, same as with any car regardless of fuel for all the reasons stated.

Been a while since last fill, knee replacement reduced running.

Swap Thursday to new Crosstar in Sage Green, interesting to see if increased HP tempts using it and then a difference
Title: Re: Winter MPG
Post by: Sean Regan on January 13, 2026, 10:05:35 AM
I think it's more about how you drive.
I usually don't drive my 23reg  Crosstar I bought a year ago, very far. Just local shopping a few times a week and visits to my golf club, six miles away, up to three times a week.
Consequently, when it's cold, the engine is required to provide for the heating system. So given the short journeys I do, it's on for most of the time.  It's also on when I let it sit on my drive with it running, if the windscreen needs de-icing before I set off.
Currently, I'm getting just over 40mpg. I'm not bothered, for 27 years I had CRVs where with this sort of motoring, the cars returned about 23mpg.
Title: Re: Winter MPG
Post by: Karoq on January 13, 2026, 11:56:48 AM
I agree with winter increasing consumption. I know mine is EV, but JAzzs also have traction battery and they DO NOT like cold weather.
In summer I can get around 313 miles at 100% charge. Yesterday It only managed  238 miles @100%.
Title: Re: Winter MPG
Post by: John Ratsey on January 13, 2026, 12:38:59 PM
Cold engines are very inefficient and cold weather makes this worse as it takes longer for the engine to reach an efficient operating temperature, not helped by the cabin heating system sucking heat from the engine. Then add the accessories using more energy. A good illustration of the cold engine effect is to select the Trip option on the big screen and show the current trip. In cold weather the trip mpg may start at around 30 and gradually creep upwards the further you go as the effect of the very poor starting mpg becomes a smaller proportion of the whole trip.
Title: Re: Winter MPG
Post by: Downsizer on January 13, 2026, 06:07:02 PM
Last Saturday I drove 100 miles at 3 degrees C, mainly on dual carriageway and the car registered 54 mpg. Today I drove 180 miles at 10 degrees C on similar roads and the car showed 61 mpg. I think it’s all about cabin heating which keeps the engine running more.
Title: Re: Winter MPG
Post by: aphybrid on January 13, 2026, 08:57:21 PM
I think the cabin heating comes from the engine, it is not electric, therefore at higher ambient engine does not have to run to give hot water to heater manifold whereas at low ambient it will run until set cabin temperature reached.
Title: Re: Winter MPG
Post by: Hicardo on January 19, 2026, 09:20:57 PM
Roughly i would say my average in winter compared to summer with the same journey types, its about 8mpg less than in summer

What that additional 8mpg inefficiency is due to is a guess, but im thinking its a combination of low temps affecting trac battery, longer times the ICE is running to heat the interior, car standing in driveway defrosting on very cold mornings
Title: Re: Winter MPG
Post by: Henners on January 29, 2026, 02:43:56 PM
(https://uploads.tapatalk-cdn.com/20260129/c561ad52db9e702c24e5748d71e267a3.jpg)

My last fill up. Loads of short trips in the cold. It looks like Honda have decided that it’s more efficient to use the excess heat from the engine to heat the car. The battery gets fully charged very quickly and stays full. But if you switch off the heating the car immediately switches to EV. I’m doing a couple of long journeys at the weekend so we’ll see how that goes


Sent from my iPad using Tapatalk
Title: Re: Winter MPG
Post by: Marco1979 on January 29, 2026, 06:34:34 PM
But if you switch off the heating the car immediately switches to EV.
I could get 65 to 70 mpg even in winter by switching off heating when I park, so the engine stays off at startup the next trip. I get out of town first, then switch the heating back on. This minimizes idling a lot. Not suitable when there is a lot of snow or ice or condensation, of course.
Title: Re: Winter MPG
Post by: NorthWales Peter on March 12, 2026, 04:37:53 PM
Around 64-70mpg.
Its when the temperature increases to around 18-22C, that's when the fuel efficiency of my 2025 Crosstar skyrockets.

Its only ever used premium E5 since ive owned it, showing 8117 miles from new, and its the first car ive seen registering over 100mpg on the fuel computer.

Im taking that figure with a huge pinch of salt, but the cars fuel economy is pretty special.
Title: Re: Winter MPG
Post by: John Ratsey on March 12, 2026, 06:42:03 PM
Its only ever used premium E5 since ive owned it, showing 8117 miles from new, and its the first car ive seen registering over 100mpg on the fuel computer.

Im taking that figure with a huge pinch of salt, but the cars fuel economy is pretty special.
A height difference between one end of a journey and the other end can make a big difference to the reported mpg. The wind can also have a noticeable effect. You need to use the average of both legs of a return trip.