erractic fuel consumption

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Polonut
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Posts: 44
Joined: Wed Nov 08, 2017 12:58 am
Drives: 2020 Polo Match 1Litre TSI
Location: Bristol UK

erractic fuel consumption

Post by Polonut »

I have a 2020 Polo Match (Petrol) 3cyl 1 litre 95.
For the past few months, I have experianced a greatly varying indicated fuel read out.
The car was very economic until recently - usual fuel mpg between 55 - even up to 60+ on most occasions.
I do a 22 mile (same) journey 4 times a week - the indicated mpg can be between 40 - 50 at best! Its not a fast road, and maximum speed is approx 50mph for about a third of that journey.
On one occasion (last week) doing the same journey, it registered 60+, the next day 49 !!!!!
I am wondering if the MAP and oxygen sensors are at fault? BUT I would expect them to fail, not fluctuate in this intermittent way.
Your thoughts would be appreciated.
Regards
Colin
PoloGTInoob
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Posts: 46
Joined: Sat Sep 02, 2023 8:54 am
Drives: 2020 Polo GTI+
Location: London

Re: erractic fuel consumption

Post by PoloGTInoob »

Does the car show your average speed? Could be heavier traffic leading to a less efficient speed and more stop start?
Polonut
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Posts: 44
Joined: Wed Nov 08, 2017 12:58 am
Drives: 2020 Polo Match 1Litre TSI
Location: Bristol UK

Re: erractic fuel consumption

Post by Polonut »

all journeys virtually identical, with no traffic interuptions.
C
PoloGTInoob
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Posts: 46
Joined: Sat Sep 02, 2023 8:54 am
Drives: 2020 Polo GTI+
Location: London

Re: erractic fuel consumption

Post by PoloGTInoob »

Clutching at straws here but could it be the wind? 60MPG might have been with a 10MPH tailwind, 49MPG with a 10MPH headwind. Otherwise, i cant help but i feel you will struggle to get an answer to this

Just googled and found this: "Headwinds and crosswinds significantly increase aerodynamic drag, which results in reduced fuel efficiency. For every 10 mph of headwind or crosswind, fuel efficiency is reduced by as much as 13%."

in my example (+10 and -10mph = 20mph difference), that could be a 26% difference to MPG, in theory. Your figures are a 20% drop. Puts it into context.
Polonut
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Posts: 44
Joined: Wed Nov 08, 2017 12:58 am
Drives: 2020 Polo Match 1Litre TSI
Location: Bristol UK

Re: erractic fuel consumption

Post by Polonut »

Thanks, an interesting comment.
My Earlier Mk5 Polo, consistantly gave unwavering good MPG despite all weather variations.
My present Mk6 was the same for the first 10K.
Will pursue this, and will have to get a digital analysis of the sensor and all hardware components.
Thanks to all for your input
C
redgti
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Joined: Fri Mar 29, 2024 5:08 pm
Drives: 2020 Polo GTI+
Location: Cornwall

Re: erractic fuel consumption

Post by redgti »

As said, wind makes a massive difference. Strong storm / heavy rain Polo GTI+ did 37MPG at 60 ish MPH.
Normally It'd be 42 or so.
The weather is bigger than any of us.
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