Hi Guys

 

I have noticed lately that my economy has dropped but the car seems to be running fine. I am a gentle driver and normally see about 45 mpg on a decent run but lately I struggle to get above 38mpg - Any ideas ??

I have only done 24,600 miles in six years but the warranty runs out at the end of March so if there is something wrong I would want to claim now. Trouble is I have little confidence in the main dealer who are bound to say it checks out fine.

Brake pads dragging……possibly?

If brakes ore binding then you can carefully check the temp of the wheel cf the others.  Use back of hand after a decent run and gently tap the centre of the rim.  If it’s really hot you’ll feel the heat before contact.  If one wheel is hotter than the others, anything above luke warm, then that could be your problem.   Otherwise could be just the normal reduction in mpg in winter, my mpg is always ~15% down in winter across several cars and almost 20 years of logging fuel consumption on our cars.  My theory at the moment is that this is down to colder and more resistant tyres and more electrical stuff running.  

@Rockinghorse  Low miles but 6 years old. 

Has it had new spark plugs?

Has it had a new air filter? 

 

Have you had colder weather than usual this winter? 

 

@DSL

Colder weather, Turbos engines love that colder air if on runs and when oil  up to temperature.

Colder weather and still Summer Tyres on and colder roads, less traction, grip, friction.  Harder rubber. *If all seasons on nit that much of a fuel increase.*

More lights on, heated, screens, seats etc etc.  An affect on fuel  consumption which does mean a poorer MPG. 

Swings and round abouts.

Winter Spec Petrol, E5 or E10. Less hygroscopic , less Ethanol than Summer spec, Maybe better than 95 Ron or 97 / 99 ron Min. 

Not the Same fuel as in Devon as in the Cairngorms. 

 

Edited 4 February, 20251 yr by Ootohere

1 hour ago, Ootohere said:

@Rockinghorse  Low miles but 6 years old. 

Has it had new spark plugs?

Has it had a new air filter? 

 

Have you had colder weather than usual this winter? 

 

@DSL

Colder weather, Turbos engines love that colder air if on runs and when oil  up to temperature.

Colder weather and still Summer Tyres on and colder roads, less traction, grip, friction.  Harder rubber. *If all seasons on nit that much of a fuel increase.*

More lights on, heated, screens, seats etc etc.  An affect on fuel  consumption which does mean a poorer MPG. 

Swings and round abouts.

Winter Spec Petrol, E5 or E10. Less hygroscopic , less Ethanol than Summer spec, Maybe better than 95 Ron or 97 / 99 ron Min. 

Not the Same fuel as in Devon as in the Cairngorms. 

 

 

1 hour ago, Ootohere said:

@Rockinghorse  Low miles but 6 years old. 

Has it had new spark plugs?

Has it had a new air filter? 

 

Have you had colder weather than usual this winter? 

 

@DSL

Colder weather, Turbos engines love that colder air if on runs and when oil  up to temperature.

Colder weather and still Summer Tyres on and colder roads, less traction, grip, friction.  Harder rubber. *If all seasons on nit that much of a fuel increase.*

More lights on, heated, screens, seats etc etc.  An affect on fuel  consumption which does mean a poorer MPG. 

Swings and round abouts.

Winter Spec Petrol, E5 or E10. Less hygroscopic , less Ethanol than Summer spec, Maybe better than 95 Ron or 97 / 99 ron Min. 

Not the Same fuel as in Devon as in the Cairngorms. 

 

 

Thanks for your comments guys.

My car has been on Skoda Allin package for the last three years and supposedly had new spark plugs and filters last year but I always find that my MPG is down after it has been serviced and gets back to normal after a few weeks and that happened again last year.

I find if I do a long run of 250 miles it seems to sort  it out. I have never before noticed a drop of more than a mile or two in winter, but I have never managed to achieve the 62 mpg that some people publish either.

I have to admit that ( senior moment ) I hadn't considered the brake issue even though my rear pads are almost shot but my fronts are only 10% worn. I am thinking it is probably the electronic parking brake issue that I have seen many people complain about.

I have never noticed any issue with it coming on and off and not detected any drag but the wear would certainly point to it. Cheers guys.

@Rockinghorse  Was there anything written that you received showing that the Spark Plugs and Air Filter were replaced, rather than that they were due to be?

Hi

 

Yes, a printed report. I know what you mean, the problem with Skoda service is that it states 'parts will be replaced if required'. I've always been very suspicious of that term.

I have always made a point of telling the service staff that I expect the service parts to be replaced and I want it in writing as 'I will be checking afterwards' - I never have. 

On 03/02/2025 at 17:10, Rockinghorse said:

Hi Guys

 

I have noticed lately that my economy has dropped but the car seems to be running fine. I am a gentle driver and normally see about 45 mpg on a decent run but lately I struggle to get above 38mpg - Any ideas ??

I have only done 24,600 miles in six years but the warranty runs out at the end of March so if there is something wrong I would want to claim now. Trouble is I have little confidence in the main dealer who are bound to say it checks out fine.

I wonder if this data might help? 

 

The Fuelly data is calculated brim-to-brim and the monthly breakdown is from the My Skoda app. 

 

My car is a 2023 1.5 TSi manual. 

 

 

 

 

Thats very interesting and well documented.

You obviously do very varied journeys whereas I do very regular ones and have never before seen such a difference between winter and summer.

My longer journeys ( 250 miles each way ) are only once or twice a year. Last year I did travel from Devon to the lake district and managed the best ever of 49 mpg, but that was the 1st time in 6 years and never seen again.

I noticed a fair amount worse consumption in the winter too.
I can do my commute with around 50-55mpg during warmer month, but on winter it drops to around 35-40 with heated seats, aircon blasting heat to defrost and defog, heated mirrors and rear screen going.

 

I recently tested a longer journey. Motorway driving, with CC set to 75, an average of 45mpg. Coming back dropped to 60, didn't make much difference to the arrival time, but avg. consumption was 60+.
It doesn't like the 70-75mph speed, but extremely happy doing 60, with revs exactly at 1500 which seems to be the sweet spot for the 1.6 TDI engine.

Its very similar with the 1.5 TSI, If you keep between 60-65 mph the  mpg is the best. 

4 hours ago, Rockinghorse said:

Thats very interesting and well documented.

You obviously do very varied journeys whereas I do very regular ones and have never before seen such a difference between winter and summer.

My longer journeys ( 250 miles each way ) are only once or twice a year. Last year I did travel from Devon to the lake district and managed the best ever of 49 mpg, but that was the 1st time in 6 years and never seen again.

Yes - a variety of Urban and Extra Urban. 

 

Given the proliferation of speed cameras I'm generally within speed limits. 

Edited 5 February, 20251 yr by pinkpanther

This happened to a car we had a few yrs ago - it was pretty well only used for a decent commute and it became noticeable that whereas it used to go a week between fill-ups every Saturday it was suddenly getting a day earlier each week.

 

I spent some time on it, and so did the dealer.  Never did get to the bottom of it.

On 04/02/2025 at 18:44, pinkpanther said:

 

 

 

 

 

 

 

I'd say you haven't had enough fill ups in February statistically. Your mpg figures are incredibly up and down is that due to the click off difference by various filling pumps? I found that with my previous Superb mkII after I was told to only fill up to first click - caused an engine management light earlier in it's life, overfilling with cheap petrol in Luxembourg!. I found the first click varied somewhat between different petrol pumps but on average it was fine of course. I used Spritmonitorl for a while - but get bored once I've calculated the approx variation from the displayed mpg after a few months.  The Superb mkII 1.4tsi display was surprisingly accurate but my previous Superb mkI was actually rather pessimistic. My latest Swace is optimistic by about 2mpg compared to Spritmonitor - cold weather affects the hybrid more though.

 

Or is it your rear brakes seizing as mentioned elsewhere re pad wear?

 

 

 

 

 

Edited 5 February, 20251 yr by bigjohn

On 04/02/2025 at 15:16, DSL said:

.......could be just the normal reduction in mpg in winter, my mpg is always ~15% down in winter across several cars and almost 20 years of logging fuel consumption on our cars.  My theory at the moment is that this is down to colder and more resistant tyres and more electrical stuff running.  

 

We used to do a regular 120 km run to the countryside (so little or no traffic) on a near perfectly flat route during our (Adelaide, Australia) winter. If there was a high-pressure zone over us then there would be no wind, but clear sunny skies with daytime temperatures typically in the high teens (say 18 deg C) just after midday. Our return journey would be at night and the temperature would plummet to 4 degrees or less and our average consumption would always be noticeably worse by about 6 mpg for the same average speed (56mpg going and 50 mpg return)

While there may have been a marginal improvement in engine efficiency from the higher density cold air it was obviously not enough to offset the negative factors.

The longer warm up time to engine operating temperature (you can bet we had the heater on), the increase in air resistance from the aforementioned higher density cool air, the reduction of effective air pressure in the tyre from the colder air and lower road temperature would increase rolling resistance as well, also, headlights would make a very small negative contribution.

 

Looking at internet references your ~15% deterioration in winter is pretty well spot on with reports from others based in the UK.

 

Edited 6 February, 20251 yr by Gerrycan

Set tyre pressures cold.  as at the outside ambient temperature. 

 

'Winter' is a season.  Different through the months Nov/ Dec, to March / April in the UK. 

Some weeks and months in various locations can have very different average day and night temperatures.

Devon vs Aviemore vs Thurso. 

13 hours ago, bigjohn said:

 

I'd say you haven't had enough fill ups in February statistically. Your mpg figures are incredibly up and down is that due to the click off difference by various filling pumps? I found that with my previous Superb mkII after I was told to only fill up to first click - caused an engine management light earlier in it's life, overfilling with cheap petrol in Luxembourg!. I found the first click varied somewhat between different petrol pumps but on average it was fine of course. I used Spritmonitorl for a while - but get bored once I've calculated the approx variation from the displayed mpg after a few months.  The Superb mkII 1.4tsi display was surprisingly accurate but my previous Superb mkI was actually rather pessimistic. My latest Swace is optimistic by about 2mpg compared to Spritmonitor - cold weather affects the hybrid more though.

 

Or is it your rear brakes seizing as mentioned elsewhere re pad wear?

 

 

 

 

 

I'm pretty sure the variation in my mpg is accounted for by Urban vs Extra Urban use and of course ambient temperature. 

 

Not noticed any issues with rear brakes, although it does of course have the infernal electronic parking brake 😬

1 hour ago, Ootohere said:

Set tyre pressures cold.  as at the outside ambient temperature. 

 

'Winter' is a season.  Different through the months Nov/ Dec, to March / April in the UK. 

Some weeks and months in various locations can have very different average day and night temperatures.

Devon vs Aviemore vs Thurso. 

Sure, but we can get quite high diurnal temperature variations, and I for one won't change all 4 tyres twice a day, everyday.

Yes, but maybe change them if a named storm is coming in to the South of the UK and low temperatures for a week.

 

Then further north during winter there is a 22 Degree C change in 24 hours a little change of pressure in the All-terrains might be Simply Clever.

 

Cordless Air pump, and pressure gauge is Much Cheapness, and no effort.

Edited 6 February, 20251 yr by Ootohere

Here we go again. 

UK Media warning people in Scotland that it might be cold in the 2nd week of February.

6 minutes ago, Ootohere said:

Yes, but maybe change them if a named storm is coming in to the South of the UK and low temperatures for a week.

 

Then further north during winter there is a 22 Degree C change in 24 hours a little change of pressure in the All-terrains might be Simply Clever.

 

Cordless Air pump, and pressure gauge is Much Cheapness, and no effort.

Yeah you do that.

Well plenty do adjust tyre pressures to suit loads carried and weather, wet, cold etc.

If bothering about a few MPG up or down for fuel then worth it.

Maybe not that noticeable day to day, but drive a EV and you will soon see how tyre pressures can affect efficiency. As weather does, and also road types / surfaces in different regions of the UK. 

14 minutes ago, Ootohere said:

Well plenty do adjust tyre pressures to suit loads carried and weather, wet, cold etc.

If bothering about a few MPG up or down for fuel then worth it.

Maybe not that noticeable day to day, but drive a EV and you will soon see how tyre pressures can affect efficiency. As weather does, and also road types / surfaces in different regions of the UK. 

For Loads yes, but do you seriously think 'plenty' do for temperatures?

Of course there many, many other factors but that is just changing the topic goalposts.

Edited 6 February, 20251 yr by Gerrycan

@Gerrycan  Yes, because of winters. Maybe just more in Scotland because they go Ski-ing, to the hills etc and travel on roads with snow or ice and then have days of the sun and warmth.

 

I do think that down south in the UK there is less adjusting of tyre pressures, even among the Emergency Services / Police.

 

Edited 6 February, 20251 yr by Ootohere