Just a final post on my fuel consumption. I previously reported that:

- my journey to work is 24 miles return;

- both ways, 7 miles of A/B/country roads, 4 miles motorway and 1 mile city;

- to work (a.m.), no more than 2 minutes in city traffic / waiting at Reds, from work (p.m.) about 5 minutes in city traffic / waiting at Reds;

- to work, downhill (per the map,but imperceptible bar one obvious motorway section of 1-2 miles) and vice-versa from work.

I previously said my consumption per the dash readout was 46mpg to work, 37 mpg from work. After further driving I can confirm that I get around these figures consistently.

Point is, that 9 mpg is a big difference between the inward and outward jouney's. While the difference in city traffic may account for some of it, I have now had the opportunity to corroborate the uphill / downhill effect over a longer journey without city traffic. The journey was just short of 60 miles return and was (overall) downhill one way and uphill the other - by map, for other than the odd short up and down, there was no real perception of this overall difference on the road.

Driving for economy, the result was downhill, 48 mpg, uphill 42 mpg.

Conclusion: When measuring consumption, you need to do so over return journeys to get an representative figure. Seems a bit obvious, but I wonder how many people do?

Edited 15 March, 201016 yr by Cauliflower

Conclusion: When measuring consumption, you need to do so over return journeys to get an representative figure. Seems a bit obvious, but I wonder how many people do?

I discovered the above was significant while recently monitoring my new 1.8TSI DSG. The uphill downhill difference being more noticeable the shorter the journey is to the point of being negligable on a very long journey. The difference is also less obvious when I drive my wife's diesel Fabia 1.9TDI. My mpg (maxidot reading) yesterday over a 50 mile return journey which included a return run of about 5 miles each way through town - the rest on A roads was 39mpg. Can't quote a tank brimming comparison yet as I'm still on my first tank full !!

I discovered the above was significant while recently monitoring my new 1.8TSI DSG. The uphill downhill difference being more noticeable the shorter the journey is to the point of being negligable on a very long journey. The difference is also less obvious when I drive my wife's diesel Fabia 1.9TDI. My mpg (maxidot reading) yesterday over a 50 mile return journey which included a return run of about 5 miles each way through town - the rest on A roads was 39mpg. Can't quote a tank brimming comparison yet as I'm still on my first tank full !!

Yes, this is important. You rarely hear about this in any road tests by car mags or indeed when you read the posts on this forum, but if I can consistently record such a variation on a 12 mile journey, then others will. Outside of a controlled (rolling road) environment, folk need to be careful about claiming mpg. Unless someone knows different ... ?