I’ve said it before and I’ll say it again: I don’t care about fuel economy, mainly because I am a low mileage driver and so fuel costs are insignificant.

However, I certainly regard economy as an interesting metric so until I get bored I am tracking some fuel economy metrics in this Google Sheet: (anyone with the link can View)
https://docs.google.com/spreadsheets/d/1Y9...m4p316f9g8

The data comes from:
1. My Journeys download from the app (so I am not able to record what happened during delivery mileage)
2. Calculations and assumptions of the cost of electricity and petrol (that’s the Data tab), assuming all electric charging is done at home (which it isn’t, but...)
3. Some formulas that calculate imperial gallons of petrol used and things like that

Headline stats as of today:
* Fuel cost per mile (petrol + electricity): £0.26
* Nearly a third of my total journey distance has been EV
* 25.8 MPG (I have not yet compared this with the Trip Computer reading)
* 21 hours driven (think of this as hours run, not of the engine, but of the car’s main electrical systems)

Bear in mind this is only after 325 miles of ownership so far, and longest journey has been like 35 miles, so it’s early days! L405 P400e Autobiography (MY2020)... Silicon Silver / Espresso

That's about 9.1l/100km. My previous L322 diesel was at 15l/100km (18mpg), So it's OK. As I make most of my trips in the city and charge the car at home and work, I really don't use gas at all...

My car is reading average 12.2 per 100km which i don`t think is to shabby?

That’s very interesting. Here’s my long term average cost per mile on an SDV8 that has averaged 26.05 mpg over the same period, working out at 21.7p per mile:

Click image to enlarge

As cost per mile is the common denominator across all engines/models, this is the best way to measure “efficiency” imho.

Interestingly, my 2004 4.4L V8 petrol/lpg cost from 17p to 22 p per mile, depending on how “Italian” I felt. My emissions during MOT were zero CO at idle and 0.08 at3000 rpm. HC was32 ppm (limit was 200).

I still don’t understand why we didn’t embrace lpg more.

The problem with lpg is there is no set chemistry ‘standardization for the lpg, the blend of gases changes so tuning becomes very problematic,

@ur

Maybe, but Europe embraced it fully and I have never had a problem in 7 years. Had it serviced every year (£100) and couldn’t tell the difference in performance over petrol.

Pleased to hear it.

For me the problems were:

1. The assumption that tax could be heaped on gas as soon as it became popular..
2. The idea that a large tank (which I would need) would lose vital boot space.
3. The less than thrilling reaction of manufacturers for warranty purposes and therefore contract hire companies.