With the current level of data I have collected I think I can now make a well informed comment on what the 330d is capable of, and compare that against what BMW claimed it could do. All this bearing in mind the car is 11 years old and has just this week ticked over 150,000 miles.
Let's start with what BMW claimed the car could achieve. The figures below have been taken straight from the BMW E46 owner's manual.
Urban - 30.7mpg (9.2)
Extra-urban - 53.3mpg (5.3)
Combined - 42.2mpg (6.7)
(Numbers in brackets are in litres/100km)
Before my data is presented it is important to understand under what conditions have the following results been collected.
- Fuel used has always been standard diesel (not V Power or any other premium diesel)
- Mileage range of fill ups: 123,000 - 150,000
- Type of roads driven on (this is an estimate).
- 2011
- Urban - 50%
- Extra-urban - 50%
- 2012
- Urban - 40%
- Extra-urban - 60%
- 2013
- Urban - 40%
- Extra-urban - 60%
- Less than 1500 of the 27,000 miles driven was on motorways.
- The figures presented are actual MPG figures, NOT what the OBC (On Board Computer) reads.
Results
The all important bit then, the results;
- Minimum MPG recorded - 30.4
- Maximum MPG recorded - 44.2
- Average MPG overall - 37.3
- Average MPG 2013 - 39.3
- Average MPG 2012 - 37.1
- Average MPG 2011 - 34.9
So what did the OBC say? Unfortunately for BMW it was very optimistic, for example, the maximum recorded MPG actually read 51.3mpg on the OBC. It seams that the higher the actual MPG is, the more inaccurate the OBC is.
Click to enlarge
Explanation
There are a number of things that might have influenced the figures I've recorded, so I will divulge such that you can understand my results and take your own opinions on my findings. You could also interpret how the figures might change based on your own circumstances.
When I bought the car I had gotten straight out of a 1.4 litre petrol Rover 25 into the 2.9 litre diesel BMW. A considerable increase in power and difference in driving style required between petrol and diesel. I was also doing less extra-urban driving. I also had problems with the thermostat in the latter months of 2011. I would account the lower MPG average for 2011 to these contributors with confidence.
In 2012 I started a new job, which involved an extended drive to the office, this accounts for the shift in urban/extra-urban percentages. Throughout the year I gained experience and learnt how to get the best out of the car leading to the overall improvement in average MPG.
You may note, on the graph above, a significant dip in the results in December of 2012, this is when my holidays from work are and as such, much more short trips and town driving (or a combination of the both).
I have also noticed that outside temperature makes a big difference to MPG. A general rule of thumb is that the warmer it is outside the higher your MPG, until you have to use air conditioning and it levels out or drops slightly.
In 2013 I have been undertaking a personal mission to increase the MPG I've been getting out of the car. I've been reading up on driving styles and practices and the results have paid off, with the highest average MPG of the three years and with the highest single MPG recorded.
Conclusion
Excluding the OBC readings, my findings are a fantastic result for BMW. A car over 11 years old with over 150,000 miles on the clock, and the MPG is continuing to rise.
In fact, I have achieved MPG figures above the quoted combined number from BMW, 44.2 vs 42.2. At 44.2 MPG a full tank of fuel will last you just shy of 600 miles (I managed 596). It is my aim this year to achieve over 600 miles to a tank, which I think is entirely possible even with urban driving percentages as much as 40%.
Would I recommend the 330d for fuel economy? Yes, you simply can't buy anything from a premium brand of that age, that price with the outstanding performance and driving ability.
If you have any questions do let me know in the comments section below, please note all comments are moderated prior to posting so don't worry if it doesn't display straight away.