Hello

 

In last few weeks I notice my car use about 20-25% fuel on same journeys compared to before. Any ideas? Don't have any errors on dash, car rolls fine so won't be binding brakes. Before on motorway 70mph avg I had easy 33-35mpg now it's 27-28... 

5 hours ago, got3n said:

 

In last few weeks I notice my car use about 20-25% fuel on same journeys compared to before. Any ideas?

My calendar says "It's Autumn". Has your regular filling station maybe started supplying "Winter diesel" early (relative to weather)?

Check tire pressure as well, colder air has an effect on them, might not be enough to trigger the TPMS but enough to lower the car's efficiency.

7 hours ago, got3n said:

Before on motorway 70mph avg I had easy 33-35mpg

have seen that numbers only in the SE; NO trip, where most of roads have 80 km/h speed limit

 

numbers for whole year from my 280ps:

Year;  km; l/100; MPG

2023  10k  11.6  24.3

2024  15k  10.1  27.9

 

@Paws4Thot

272/280ps have no connection to diesel

 

On 29/10/2024 at 23:01, got3n said:

car rolls fine so won't be binding brakes

I’ve had my 280 doing similar and put it down to the colder weather, I’d dropped from around 31-32 mpg to 29ish. I did go around the car putting the back of my hand against the alloys and found the offside rear was warm when the others were quite cool after my journey from work the other day so I’ve got a slightly binding caliper but noticed no obvious difference in rolling resistance. 
Might be worth a try?

On 30/10/2024 at 04:37, Paws4Thot said:

My calendar says "It's Autumn". Has your regular filling station maybe started supplying "Winter diesel" early (relative to weather)?

In a 272 ,,,, 

Winter petrol, colder temps, more draw of electric... Many reasons. I recently got 39 MPG on a round trip at the end of October in my 272, 3 up, pootling up to Alton Towers from Plymouth and back although I have thought that its very warm for this time of year (10-12 degrees at 6am - in Plymouth anyway) and is only just starting to drop in temp.

 

As above, check wheels for binding calipers, tyre pressures and decent fuel.