Just updated my spreadsheet ( kept for for expenses as well as general interest ) of MPG since owning the car. Interesting that it shows a marked difference between spring/summer and autumn/winter motoring.

 

Total distance covered 60,955 miles with 1062 gallons of diesel ( Tesco ). Pretty much same journeys every day, MPG's calculated as a rolling average of 4no tankfulls.  

 

 

Hi. Thanks for uploading this. It pretty much confirms what I/we already knew...

My current Octavia 150Tdi/DSG is also pretty 'Night & Day' when it comes to winter vs summer driving MPGs.

I've had most of the Skoda/VAG TDIs in the range over the years, i.e. 90Tdi, 105Tdi (Greenline Superb 2), 105Tdi (Non- Greenline Octavia 3) 110Tdi (Octavia 2) , 140Tdi (Octavia 2 L&K).

All of them showed the same pattern as your beautiful Graph, above shows.

 

It doesn't feel nice to see a 10+ MPG difference from best to worst, but I guess it is what it is. 

 

 

It is interesting to see how your 1.6 TD1 compares with my manual 1.5 TSI. I don't do anywhere the mileage you do only averaging about 6,000 miles pa over the past 3 years and much of mine is short journeys. I'm averaging 43.2 mpg overall though I can't differentiate between summer/winter figures. Most of the time I use ECO mode and tend to drive with fuel economy in mind. The best I have achieved on a long journey (over 150 miles) is 62.8 mpg.

On 30/01/2023 at 19:32, MASKO said:

It is interesting to see how your 1.6 TD1 compares with my manual 1.5 TSI. I don't do anywhere the mileage you do only averaging about 6,000 miles pa over the past 3 years and much of mine is short journeys. I'm averaging 43.2 mpg overall though I can't differentiate between summer/winter figures. Most of the time I use ECO mode and tend to drive with fuel economy in mind. The best I have achieved on a long journey (over 150 miles) is 62.8 mpg.

I must admit to have been checking my fuel consumption regularly over the last 30 years ( not when I had a company car & fuel card though), and as you mentioned I never noticed much of a difference when driving a petrol car only diesel.

That is an interesting graph but and while I would be the first to agree that temperature is a factor I am surprised that it is that much.

There may be a couple of other factors? Different diesel formulation for winter and the peak also coincides with the summer school holidays so could there be better traffic flow without all the teachers travelling and student pickup/dropoff (it is very noticeable here)? Do you put different winter tyres on? How long was your commute as shorter journeys would be more affected by cold than longer journeys (proportionately longer time to warm up engine to operating temperature)? 

 

I used to record my consumption religiously but got to a point where I could 'feel' there were so many factors at play at any one time that there was no real point. My wife is now doing most of the driving in our Octavia anyway, so I wasn't likely to be critical of her driving (and our marriage survive?) was I.  

I do refuel the cars and still just check the figures that there are no major aberrations from the norm (~6L/100) to indicate any issue.

 

When we had a 1.9pd Octavia we used to do a regular 200km round trip on a Saturday to watch our son play his sport. There would frequently be a high pressure over us so there would be no wind and a midday temperature of about 20 degrees, running on near empty roads flat roads at whatever speed limit applied. The return journey would be after dark (after the game and a clubroom meal) and the temperature would fall quite quickly (clear skies) to between 5 and 8 degrees. The return journey would always average about 5mpg less in otherwise similar conditions on the same route back. Most of that would be the effect of the temperature and a small part due to running headlights in the dark. I used the cruise control extensively.

 

1 hour ago, Gerrycan said:

Different diesel formulation for winter and the peak also coincides with the summer school holidays so could there be better traffic flow without all the teachers travelling and student pickup/dropoff (it is very noticeable here)? Do you put different winter tyres on? How long was your commute as shorter journeys would be more affected by cold than longer journeys (proportionately longer time to warm up engine to operating temperature)? 

 

The summer/winter formulation theory is interesting and something I haven't thought about. 

Summertime travel is easier here as well, noticeably less traffic about on my commute.

Commute has been the same every day/week/month/year. Apart from an occasional trip to the supermarket it's 2 x 50 motorway miles Mon-Fri, 1 x 65 motorway on Saturday & 1 x 65 motorway on Sunday.

No winter tyres and fill up once a week at same Tesco station. 

There is Winter formulation Diesel & Petrol distributed starting in October in Scotland & the North of England until the end March.

Further south comes from October on.

 

If the weather / ambient temps are not cooler in the days or weeks the fuel consumption is not lower than during the same temps at other times of the year.

Plenty fleets of HGV's and Company vans and cars with Managers that know what their vehicles use fuel wise and by the weather up and down the UK.

You are getting the Cetane you pay for.

 

................

With e5 petrol it is not the same nation wide and many have no idea what they get, but they get the minimum octane of 97 ron or 99 ron, maybe better, but not lower.

The E10 is 95 ron min, and might well be higher as less hygroscopic as this is what the winter formulation requires. 

 

 

The tanker was delivering the first winter fuel that year when i took the picture and i filled up there on my way away places and on my way back and was getting better economy than the weeks up to then as the weather was warmer that October and November than in September and August.

But then i know the mpg i get in what ever i am driving doing the same routes in what ever directions at the different times of years, weather and if day time or during the night, and i know the time so speed i am doing.

*Ask your usual  filling station staff when their deliveries change from Summer to winter diesel.* They might not know anymore than most drivers know.

 

Consider journey differences by time of year / seasons and ambient temps so regen frequency when looking at the fuel efficiency.

http://briskoda.net/forums/topic/456194-low-fuel-consumption-16tdi-dpf-engine

 

 

Edited 6 February, 20233 yr by toot

I have absolutely no idea how the winter/summer diesel formulations affect calorific value, I just thought it was to maintain a working viscosity at low temperatures and that maybe the winter 'dilution' may compromise consumption a bit. I've never owned a diesel in the UK and now live in a coastal Mediterranean type climate so would only see morning frost if I travel inland in our winter and again I have no clue whether our diesel varies to seasons in our region, Probably not but it would in Australian 'Alpine' areas

 

@Gammyleg that is really good consumption you are getting from a small diesel engine in what is a big vehicle but your driving profile would obviously help a lot, From what you describe temperature would have to account for a lot of the difference.

 

Like @MASKO I can get in the 60's returns with my 1.4tsi on a longer journey but that will not happen with adverse factors such headwinds, tight schedules or even very high temperatures when the aircon is working overtime and then it can drop down to the 40's.

 

I do remember my 1.9pd Octavia was far more tolerant of adverse conditions and on one notable long journey we were heavily loaded, pushing at the speed limit through strong headwinds, 40 deg temps (max aircon), locust plague (very noisy and not fun) and even an extensive accumulation of three foot deep wind-blown seeds which totally obscured the road like snow but had the resistance of fairy floss. Still got consumption in the mid/high 50's though which our current petrol engine, good as it is, would not have been able to match.

This is interesting - I thought there was something wrong with my 150tdi estate as my late 60s mpg in the summer on a very repeatable and monthly 300 mile round trip in late evening on the m5 & m6 had dropped to mid 50s by mid winter. 
Also an autocar writer mentioned they got 1113 miles from tank a 2021 superb estate dsg 2l tdi 150 on a summer trip back through France with family and luggage - that’s just over 70mpg.

What size tank has a 1.6TDI have?

 

?

Did the writer say what the capacity of the fuel tank was in the 2.0 TDI car they had? 

Or if buying and using standard Diesel or was it Premium Diesel in continental Europe? (maybe they are the same cetane rating, i do not know)

 

66 litre.

Then a TDI with Adblue.

 

66 litres is almost 14.5 imperial gallons.

1113 divided by 14.5 is 76.75.   that is MPG.  (But you are not going to run a tank to empty.)

Getting 70 mpg from every gallon is amazing if not just doing a non stop trip, but one with with cold starts, town driving etc and as loaded car.

 

This is a Briskoda member.   Maybe subscribe.

 

 

 

 

 

Edited 11 February, 20233 yr by toot

8 hours ago, Evilbert said:

This is interesting - I thought there was something wrong with my 150tdi estate as my late 60s mpg in the summer on a very repeatable and monthly 300 mile round trip in late evening on the m5 & m6 had dropped to mid 50s by mid winter. 
Also an autocar writer mentioned they got 1113 miles from tank a 2021 superb estate dsg 2l tdi 150 on a summer trip back through France with family and luggage - that’s just over 70mpg.

I can well believe the 1000+ miles to a tank, just last week mine showed a range of 965 miles with 169 already covered since refilling. I usually use Sainsbury's diesel but it does seem to give better economy on Esso.

 

Just to show my above economy can be replicated over a longer time period here's another showing I did 923 miles since refilling and still 90 mile range left. The fuel economy for such a large car really is very impressive. I spend lots of time on the motorway driving up and down the UK for my work, my Superb is now 4 months old and has 12k on the clock, I expect the economy to improve with summer temperatures. Time will tell if I can reach 80mpg+ on a run.

 

The autocar article:

https://www.autocar.co.uk/opinion/new-cars/why-there-still-place-diesel-cars-2023
 

 

I would ask him a question if i could. 

When he brimmed it did he actually 'Vent the tank' and get as much as an extra 7 litres in, 

then when he rolled into the filling station with 0 range and brimmed it again was it just 66 litres that went in? 

On 12/02/2023 at 02:35, toot said:

I would ask him a question if i could. 

When he brimmed it did he actually 'Vent the tank' and get as much as an extra 7 litres in, 

then when he rolled into the filling station with 0 range and brimmed it again was it just 66 litres that went in? 

I know that the ability to 'vent the tank' with a specific fitted lever/button was a feature on certain past VW group vehicles (Fabia?) but I'm not aware that any recent Skoda has any such facility, certainly not on the mk2 diesel or the mk3 petrol Octavia I've owned, or any reference to it in any post in the Superb section, other than your good self that is.

Based on the rare occasion where a driver has near emptied their tank and posted the refill amount and I think it is fair to say that most VW group vehicle's fuel tanks have a about 5 litres more capacity than the published figure (although it could be even more).

 

Personally I'd be disinclined to risk running the tank empty with modern high pressure fuel injection systems pumping air or running the in-tank fuel pump without it being cooled by the fuel it normally bathes in, or having to do that embarrassing jerrycan walk to the nearest petrol station.

Fair enough if they can not be vented.

Take the tank out the car and put it on the ground and the tanks capacity will be 66 litres and some more.

Once in the car there is more fuel than that goes in and in smaller cars that can be 5-7 litres or more. 'Up the pipes' from the tank to what you see if you are brimming it.

So if someone is getting good fuel consumption like over 60 mpg even 70 mpg and has a range of 0 left then it is good if they just say how much fuel they put in to brim it back to where there were before running it to zero.

 

An interesting post by @EC73LDN  I wonder if they have replicated that amount at a refill. 

http://briskoda.net/forums/topic/345599-increae-in-size-of-fuel-tank

 

http://briskoda.net/forums/topic/408362-fuel-tank-capacity

 

 

Edited 14 February, 20233 yr by toot

2 hours ago, toot said:

Take the tank out the car and put it on the ground and the tanks capacity will be 66 litres and some more.

I'm sure lots of folks will be eager to test this theory! 

Easy enough at a scrap yard.   Or as many here have old cars and projects, see how much that 45, 50, 55 litre or even 60 litre tank takes. 

The tanks are there for people to try.   

 The Manufacturers are giving a tank capacity.   Not a fuel capacity, and the litres that get used before a gauge even shifts, as many post about like in a Moment of joy thread yesterday.  Off Topic Section.

 

 Easier is when you collect a car with near no fuel in is fill it up and see how far you go.

Then when you fill up with it showing zero but the car is still running because it has fuel how much does it take to get back to full.

 

Does a journalist picking up a near empty car put it back full, or near full.    Picking up a hire or courtesy car filled up you might well do, well as much as you need to put in.

I drove mine for around 5 miles with it showing zero miles a few weeks ago. Got about 64 litres in it.

This is an excellent Topic. Not new by any means, but some of the responses and contributions are really quite good IMO.

Not sure why, but I have noted over the years that some of the best (verified with refill data) Briskoda consumption claims have come from Superb diesel drivers despite the Octavia having the same drivetrains and smaller and lighter bodies. That's mpg, not distance on a tank.

Must be the superb Superb drivers that are the difference  

 

 

Edited 17 February, 20233 yr by Gerrycan

I set myself the target of covering 1000 miles before refueling which I managed today. Still had a 20 mile range showing when I pulled onto the forecourt. Looking forward to seeing how far it will go when the summer temperatures are here in a few months time and the economy improves.

 

I put in £120.00 which was just over 70.6 litres.

 

Pictures below.

Edited 23 February, 20233 yr by cnc

Wow, 70 litres...you must have been running on vapours.

I'm currently getting low 60's now the weather has turned a bit milder.

Must have a bigger tank than mine. One time when I refuelled, I was running on zero miles for the last few miles on the way to the fuel station and still only got 64 litres in. The tank is supposed to be 66.

On 24/02/2023 at 06:22, cnc said:

I set myself the target of covering 1000 miles before refueling which I managed today. Still had a 20 mile range showing when I pulled onto the forecourt. Looking forward to seeing how far it will go when the summer temperatures are here in a few months time and the economy improves.

 

I put in £120.00 which was just over 70.6 litres.

 

Pictures below.

 

By my calculations for distance and refuel quantity you actually got 64.49 mpg, which means your display is pretty accurate, possibly pessimistic, even after allowing for minor differences refuel 'click' point, and of course accuracy of the refueling point pump.

Really good driving discipline over that sort of distance.