Driving style vs fuel consumption
This week, I’ve had my clearest indication yet that driving style affects one’s fuel consumption. The nature of my work requires that I do a lot of driving - since February ‘06 I’ve driven 100 000km.
My company vehicle is a double cab Mazda Drifter 2.5 turbodiesel. Yes, that’s right… the author of GreenCars drives a gas-guzzling 4×4! But in my defense, it’s a company vehicle and I do work in rural African villages so a 4×4 is unfortunately a necessary evil. Nevertheless, I’ve been trying for months now to convince my boss to trade in the Drifter for a much greener FIAT Panda 4×4, but that’s another story altogether.
Anyway, typically, the Drifter returns about 11.5 - 12 litres/100km at a steady 120km/h depending on whether or not I have the airconditioner running. This week, however, I’ve detected a problem with my front left wheel bearing, so I limited my driving to a maximum of 100km/h throughout the 1100km or so that I drove. It’s also been cold, so I didn’t use the A/C at all. The results were pretty clear - I averaged 9.8l/100km over the duration of the trip. That’s a fuel saving of about 14%, just by driving 20km/h slower. Assuming diesel costs R7 a litre, I saved about R115 on that trip and emitted about 47 kg less CO2.
Given that a faulty wheel bearing increases the rolling resistance of that wheel, it’s likely that these fuel consumption figures would have been even lower with a good wheel bearing.
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Comments
Nice going there Carl!
As you and I happen to know eachother, I have been trying to convince people of this fact for years.
I have been commuting from Umkomaas to Durban since 2002, and after converting my horribly thirsty Polo Playa 1.4 into a 2.0 litre…I figured a better powert to weight ratio might help, as well as give me some fun…The consumption actually improved from 9.5 l/100 as a 1.4 to 7.8 on average.
Late 2003, I got a fantastic deal on the Playa (got my money back plus!!), I bought a new 1.6 Polo Classic. As I used the same route every day, and filled up once a week, it was very simple to quickly calculate pretty reliable figures (NOT the the ones on the Computer readout, but using the old fashioned method of a calculator, and keeping note of every litre and Rand spent, my consumption improved dramatically as the kilos ran up, but it varied from a best of 5.2 l/100 to a worst of 6.8 l/100 over 30 000 km. The bad figures tended to come after a headwind problem on the coast…or when I had had to push her for some reason or other.
I also discovered that cruising at 100 in the slow lane v/s 120 in the fast made no difference in time taken to get to Durban from home! For some reason or other, people would flash past me near Toti, only for me to sail past them just after the airport!
Driving in the “fast” lane …certainly between here and Durban, actually retards time taken as everyone starts bunching rigidly in the right hand side…whereas my very economical cruise in the left actually meant me arriving at work totally relaxed. I never worked out the overall saving, but, but it must have run into quite a bit over the 30 000 km.
Once again the buying bug bit in July 2006 and I bought a 140 RunX.
Exactly the same driving style, ended up with a consumption average of 7.8 l/100 over the past year…THE 1.4 is once again showing that power to weight ratio DOES count!!
For some reason or other, the 1.4 seems to always be more of a gas guzzler than the 1.6.
I would be interested to hear if anyone has any comments!
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