Author Topic: MPG for those interested  (Read 435949 times)

Lord Voltermore

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Re: MPG for those interested
« Reply #780 on: September 26, 2026, 09:44:28 AM »
Whilst I can understand  that many will want to monitor their fuel use , and other expenditure , in great detail and accuracy , I have never felt the need to constantly monitor it  down to the last drip of fuel or how I spend each penny .
 
While there is truth in the old adage "Look after the pennies and the pounds will take care of themselves".  I have perhaps been fortunate (or naïve in thinking ) that  having sufficient pounds left in the bank each month,and an awareness of  roughly how much I am spending on non essential luxuries  (which includes a newish Jazz and fuel spent on recreational trips) is enough for me to know whether I  am living within my means.

Would I really change my driving habits  knowing I am really only getting 60 mpg  rather than the 62 mpg  shown on the fibometer?  ?  Nope.  My bank balance wouldnt change.   The  Fibometer  is  accurate enough to encourage me to moderate my driving style  to increase mpg.  And I have spent many pounds from my bank balance on a relatively small hybrid car to minimise the environmental impact of my recreational use of the car. 
My IQ test came back negative

5thcivic

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Re: MPG for those interested
« Reply #781 on: September 26, 2026, 12:53:10 PM »
I agree absolutely with everything Voldermore says. I remember 50 years ago with my first Mini having a green notebook in the "glovebox" calculating spend and mpg.

Still find it interesting from an engineering, spec sheet and mathematical view to see what people calculate.

Everyones's driving styles, geography, traffic jams and temperatures will be different, checking manufacturers claims independently is always good.

Downsizer

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Re: MPG for those interested
« Reply #782 on: September 26, 2026, 04:22:13 PM »
All cars are less fuel efficient at higher speeds for obvious aerodynamic reasons, but in the Jazz hybrid it is particularly noticeable for engineering reasons. In view of the current world shortage of oil I think it would make sense to introduce a national 60mph speed limit. It was done before and the economic costs in lost time would be minimal. It would also have safety benefits.

Jazzik

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Re: MPG for those interested
« Reply #783 on: September 26, 2026, 06:57:06 PM »
I’ve been tracking the fuel consumption of our last four cars on "Spritmonitor" (https://www.spritmonitor.de/en/) for about 18 years now—out of curiosity and to compare the fuel economy of these different vehicles under various conditions.
It really takes no effort at all; it’s very simple, especially with the app.
If nothing goes right, go left!

coldstart

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Re: MPG for those interested
« Reply #784 on: September 26, 2026, 07:46:37 PM »
Keeping detailed records not only shows how I'm *) adapting to a new car, but also warns me early if there should anything be amiss!

*)  I'm always amused to read about "the car settling in" after a few thousend miles...
Well, that might have been a truism in the nineteen-sixties?!? - With modern cars and high precision manufacturing it will be more likely the human component "settles" and gets accustomed to the new car than otherwise :D

Addendum:
What model year was your last car exactly, where the user manual told you to get an engine oil change after the first few hundred miles?
« Last Edit: September 26, 2026, 08:15:43 PM by coldstart »

Jazzik

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Re: MPG for those interested
« Reply #785 on: September 27, 2026, 12:01:19 AM »
What model year was your last car exactly, where the user manual told you to get an engine oil change after the first few hundred miles?

That was a long, long time ago...
But this is what the owner's manual of our future plug-in hybrid says:

Break-in Period

● The powertrain needs break-in. It is recommended that this be done within the first 2,000 km in HEV-ECO mode by smooth driving, instead of high-speed driving. The following practices can effectively prolong vehicle service life:
● Avoid flooring the accelerator pedal when starting and driving the vehicle.
● Avoid speeding.
● Avoid emergency braking within the first 300 km.
● Do not maintain a high or low speed for too long.
● During the break-in period, the proportion of HEV mode (with the engine involved in working) must not be less than 50% of the driving mileage.


In practice, this means the petrol engine needs to have run for at least around 1,000 kilometers to properly break in. For convenience, many dealers advise setting the car to HEV mode right from the start to ensure the engine accumulates sufficient running time.
Following the break-in period, the engine oil and oil filter are replaced (free of charge at our dealership) at a mileage of between 2,000 and 3,500 kilometers.

The brands and vehicle categories that still require a mandatory "break-in service" involving an oil change today fall roughly into three groups:
1. High-performance divisions (sports cars)
2. Motorcycles (broad industry standard)
3. Specific plug-in hybrids (PHEVs) from China
Like BYD (with its DM-i technology)—where the internal combustion engine often acts as a generator and must be capable of kicking in while cold.


If nothing goes right, go left!

coldstart

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Re: MPG for those interested
« Reply #786 on: September 29, 2026, 09:40:19 PM »
Most of this makes sense even today!
e.g.
* "braking" in (pardon the pun) of the brake pads!
* "avoid flooring the accelerator when starting and driving the vehicule"
" avoid speeding - well: Isn't that some sound advice! :D
* avoid emergency braking within the first 300kms  (sure: See above: The brake pads have to be "aligned" first to be most efficient)

Apart of the "braking-in" all of the above points make absolutely sense for any car of any age!
This is just "common sense"!

(okay, I do understand that nowadays "common sense" seems to be a (hopefully!) highly researched topic on the search- / AI-engine of one's choice)

Lord Voltermore

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Re: MPG for those interested
« Reply #787 on: September 30, 2026, 09:08:42 AM »
If I remember correctly when my 2021 car was new there were  discussions on this forum that Honda  suppressed the engine settings  to minimise excessive and harsh usage during the engines first 1000 km . ie they had imposed a 'running in period' . The car  was still responsive  but  could be abused if you  " drove it like you stole it"   ;D)

I cant remember if this was a fact, or merely an urban myth at the time . But I did get the impression that the engine behaviour changed slightly at about 600 miles/1000km. Maybe this was a result it genuinely 'loosening' up   ,or perhaps I imagined it because  I was expecting a change.

I didnt notice any such change  with my new 2024 car. But treated it gently anyway.
My IQ test came back negative

Kremmen

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Re: MPG for those interested
« Reply #788 on: September 30, 2026, 09:31:54 AM »
My 2021 car I have no idea about engine suppression because it only cut in and out to keep the battery charged. My style of driving never used to engine to drive the wheels

I would have had no idea whether it was running in or not
Let's be careful out there !

John Ratsey

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Re: MPG for those interested
« Reply #789 on: September 30, 2026, 04:32:14 PM »
In view of the current world shortage of oil I think it would make sense to introduce a national 60mph speed limit. It was done before and the economic costs in lost time would be minimal. It would also have safety benefits.
This http://news.bbc.co.uk/onthisday/hi/dates/stories/december/15/newsid_2559000/2559807.stm ?

Encouraging drivers to adopt a more economical driving style would be one way to fend off demands for a reduction in fuel duty.
Previously 2025 Jazz Advance, previously 2022 HR-V Elegance, previously 2020 Jazz Crosstar

Downsizer

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Re: MPG for those interested
« Reply #790 on: September 30, 2026, 06:25:35 PM »
In view of the current world shortage of oil I think it would make sense to introduce a national 60mph speed limit. It was done before and the economic costs in lost time would be minimal. It would also have safety benefits.
This http://news.bbc.co.uk/onthisday/hi/dates/stories/december/15/newsid_2559000/2559807.stm ?

Encouraging drivers to adopt a more economical driving style would be one way to fend off demands for a reduction in fuel duty.
Yes, but I doubt if encouragement would change many drivers behaviour if cash savings isn’t working! I think this time the limit would need to cover motorways as well as dual carriageways. There are many more motorways now and they are mostly very busy.
« Last Edit: September 30, 2026, 06:29:13 PM by Downsizer »

coldstart

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Re: MPG for those interested
« Reply #791 on: Today at 06:04:04 PM »
I didnt notice any such change  with my new 2024 car. But treated it gently anyway.
I'm now at 25'000 miles plus and am still "running in" my Jazz :)
And I do regularly get rewarded at the petrol station for this!

Folks: It's just common sense (and with today's fuel prices it truly pays off!).


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