Driving Audit

One of the downfalls of moving away from Melbourne is the distance from work. Since moving in August, I had been travelling by car up to 800 km a week to work. Luckily for me (and the environment) my workplace is flexible and I am able to reduce my hours and work a day from home, which will mean only travelling 400 km a week, plus whatever we do around town and on weekends.

So 450 km+/week.

Previous to working, I tried to walk, cycle and catch public transport as much as possible, only using the car 100 – 150 km per week on average.

Unfortunately I cannot pick up my office and dump it here in downtown Ballarat, and I love my job, so for now I’m staying put – so what are my options to reduce my driving impact?

Public Transport

I could stop driving altogether and utilise public transport, which is probably my greenest option. This idea sounds good in theory, with the availability of trains and buses, but in practice this did not work so well. This is what my day looked like when I took public transport to work…

  • 5:45 am – Caught the bus to the train station (it arrived at 5.55 am)
  • 6:10 am – Arrived at the station
  • 6:20 am – Hopped on the regional train towards the city
  • 7:10 am – Made it half way to Melbourne but couldn’t go any further due to a broken down train ahead of us. We were all told to get off the train and wait for buses to arrive
  • 7:20 am – Called a friend in town, who catches the train to the city, to see if I could borrow their car to take to work, as getting a bus into the city and another train out to the ‘burbs would be at least 1-2 hours
  • 7:40 am – Friend arrived, took their car into work
  • 8:25 am – Arrived at work – almost three hours after leaving home.

Now, I’m sure this was an anomaly but, because I had to drop the car off and the keys, I was in transit for more than three hours on the way home too (the regional train was 40 minutes late). That day I spent more time travelling to and from work than actually at work.

I’m exhausted just remembering it all!

As a general rule, public transport is a more sustainable option than driving. However, there are a few factors that affect which type is better for the environment including:

  • Distance
  • Type of fuel used (electric, diesel, gas, unleaded)
  • Maximum capacity vs. engine size
  • Number of people using the service at the time

I could try the public transport option again and hope for a better outcome, and I can definitely utilise it around town with the convenience of a bus just down the road and the sheer excitement riding the bus gives to a toddler – it’s definitely one of my favourite options.

Driving Efficiently

As much of an environmentalist I like to call myself – sometimes convenience still trumps what’s best for the planet. I can’t see how I could get Peanut to daycare (taking a multitude of buses or cycling 10 km adding a minimum 40 – 50 minutes to the commute) and travel the 3 hours via train and bus without a) losing all of my day to travel and b) losing my mind to the tedium of peak hour public transport commute… although I would get a lot of books read!

So while we all know driving is a heinous environmental crime, there are ways we can drive more efficiently to reduce the amount of fuel used.

Green Fleet recommend doing these 15 thing to reduce our impact:

  1. Drive Smoothly – Fluctuations in speed can use as much as 1/3 more fuel compared to smooth driving. Avoid accelerating and breaking too hard and try to steer as smooth as possible. Using cruise control on the freeway can help conserve fuel.
  2. Service Your Car Regularly – A well tuned engine can improve performance by up to 4%.
  3. Keep Tyres Pumped – Tyres that are kept at the correct pressure are safer and last longer (also fewer resources required if you replace your tyres less). Did you know a tyre that is under-inflated by 1 psi (pound per square inch) can reduce fuel efficiency by as much as 3%!
  4. Get the Junk Out of the Trunk – For every extra 45 kgs of weight in a vehicle, the fuel efficiency can drop by 2%…. time to take the spare pram out of the boot!
  5. Remove the Roof Rack – Removing the roof rack when not in use can reduce the overall weight as well as improve aerodynamics. A car with roof racks will create drag and can reduce fuel efficiency by as much as 5%.
  6. Use the Correct Oil – Using the manufacturer’s recommended lubricant can improve fuel efficiency by up to 2%. Higher quality oils can help your engine to operate more efficiently too.
  7. Use Higher Gears – The higher the gear, the lower the engine speed. When driving a manual, use the highest gear appropriate, without causing the engine to chug along at an ultra-low rpm. No flogging the car in fourth gear along the freeway!
    If you drive an auto, the car will shift itself through the gears more quickly and smoothly if you ease back slightly on the accelerator when the car has gathered sufficient momentum.
  8. Avoid Idling – This sounds like it could also be applied to life advice but Green Fleet recommend turning the engine off if you’re in a queue or waiting for someone. If you’ve driven a relatively new car, you’ll notice they shutdown when your foot isn’t using the accelerator.
  9. Slow Down – The faster you travel, the more wind resistance you’ll encounter, this means your car needs more fuel just to maintain the speed. Fact: travelling at 110km/hr uses up to 25% more fuel than cruising along at 90km/. For driving around town (stop/start), 60km/h is the most efficient.I did some maths on this:
    • Work is 99 km away, for 50 km the speed limit is 110 km/h and for 25 km the speed limit is 100 km/h. What I want to know is, is doing 10 km/h over the limit going to get you to your destination faster?
    • Travelling at 110 km/h for 50 km takes 27.16 minutes, while travelling at 120 km/h takes 25 minutes. Gaining 2.16 minutes.
    • Travelling at 100 km/h for 25 km takes 15 minutes, but if you increase that speed to 110 km/h you shave off 1 minute and 22 seconds! By speeding 10 km/h over the limit (which many people do in a vain attempt to get to where they are going faster) I would gain a grand total of 3 minutes and 38 seconds, meanwhile burning through a shitload extra fuel just to do so.
  10. Use Air Conditioning Sparingly – Using the AC puts extra strain on the engine and uses more fuel. Instead use the fan on mild days and save the AC for those stinkers – hard to do when you live in Australia!
  11. Check the Air Filter – The air filter keeps impurities from damaging your engine. Replacing a clogged air filter can improve fuel economy by as much as 10%.
  12. Be Picky WIth Your Travel Times – By avoiding peak hour traffic, you’ll spend less time idling and driving in slow-moving traffic and in turn, consume less fuel.
  13. Conserve Momentum – Slow down early and smoothly to allow traffic lights to turn green, rather than stopping completely or abruptly. Green Fleet also suggest speeding up a little before a hill to allow the vehicle’s momentum to carry it up the hill without working the engine harder.
  14. Use the Hand Brake on Slopes – Do you use your hand brake when stopped temporarily at the top of a slope? If you do you’re saving fuel! If you do not, then you’re only partially disengaging the clutch (manual) or using the accelerator (auto) to keep your vehicle from rolling back, which uses more fuel.
  15. Keep Calm! – This point is pretty much the same as the first one, but 15 tips sounds better than 14 I suppose… any who, when you’re driving erratically you’re more likely to make judgement errors. Fuel efficiency is all about being a smooth operator.

The Green Vehicle Guide

I know sweet f.a about how cars work, so luckily for me the Australian Government has released the Green Vehicle Guide (GVG) to help me make sense of vehicle emissions.

The GVG helps “to identify the most environmentally friendly vehicle that meets your needs when buying a new car”. Here is the breakdown:

  • Carbon dioxide (CO2) is the main greenhouse gas produced by cars.
  • The National Transport Emission estimates if all Australian’s purchased cars that rate the best on the GVG, emissions for new light vehicles would be over 50% less.
  • Cars are also rated by something called the Euro Level – an indication of the air pollution standard of the car. The Australia Design Rules require all vehicles supplied to the Australian market meet a minimum standard of Euro 5.
  • The European minimum is a Euro 6, which is more stringent than a Euro 5.
  • The amount of CO2 released is dependent on the type of vehicle and the type of fuel.
  • Over 11% of all greenhouse gases produced in Australia are from light passenger and commercial vehicles.
  • All new vehicles weighing up to 3.5 tonnes gross vehicle mass sold in Australia are tested to determine both fuel consumption and the level of CO2 emissions emitted.
  • These tests produce three values:
    • The ‘combined’
    • The ‘urban’
    • The ‘extra-urban’
  • The Guide uses the combined CO2 emissions value as the primary basis for ranking vehicles.
  • Cars also emit air pollutants into the environment such as: carbon monoxide (CO), nitrogen oxides (NOx), particulate matter (PM), volatile organic compounds (VOCs) and benzene ((CH)6).
  • Air pollutants are bad news because they create photochemical smog and are detrimental to health.


My little Nissan Almera.

Australian 2018 Car Statistics

From the Australian Bureau of Statistics:

  • There were 19.2 million registered motor vehicles in Australia as at 31 January 2018, which is bout one car per adult.
  • The national vehicle fleet grew by 2.1 per cent between 2017 and 2018.
  • Toyota topped the list of passenger vehicle makes for the 13th consecutive year with 2.9 million registrations.
  • Diesel powered vehicles constitute 23.4 per cent of the national fleet, up from 17.2 per cent in 2013.
  • Petrol powered vehicles decreased by 1.1 percentage points to 74.6 per cent of the national fleet.
  • Diesel powered vehicles increased by 1.3 percentage points to 23.4 per cent of the Australian fleet and remains the fastest growing fuel type
  • Average age of all vehicles registered in Australia was 10.1 years, unchanged since 2015.
  • Tasmanian vehicles reported the oldest average age at 12.8 years, whilst the Northern Territory and Australian Capital Territory had the youngest fleet with an average age of 9.4 years.

Car Comparison

Here is a comparison of emissions and energy consumption of:

  1. The best performing car – Hyundai 2019 loniq EV
  2. The most popular car – Toyota Corolla 2018 (the most popular was actually a Toyota Hilux which I’m betting is only up top as it’s used as a fleet vehicle so I went with next best)
  3. My Car – Nissan Almera 2012

CaptureThe top 20 performing cars on the GVG were all pure electric, which, understandably made it difficult to compare the three cars as they don’t emit CO2 (although they do consume energy). The Hyundai annual fuel cost is 1/3 that of the Toyota and Nissan.

The Nissan and the Toyota were fairly comparative, with the Corolla coming out just on top.


In the last 12 months I travelled 25,000 km, with a fuel consumption of 6.3 litres per 100km, that equates to 3.73 tonnes of CO2 per year. While in 2017 my car emitted approximately 1.29 tonnes of CO2. To put into perspective of how much CO2 that is – a meat eater’s diet causes approximately 2.6 tonnes of CO2 per year versus a vegetarians diet of approximately 1.4 tonnes.

Kilometers clocked on my car February 2018 and 2019 respectively. Sneaky little fact, the arrow next to the petrol symbol points to the side the tank is on – handy info for when you fuel up.

Fuel Type


As we’ve already discussed, petroleum (petrol), releases CO2 into the atmosphere, one of the main greenhouse gases contributing to climate change. The extraction of petrol from the earth is invasive, destroying habitats and polluting the air and water. I drive a petrol car.

See the source image

An oil covered pelican following the Deepwater Horizon Oil Spill in the Gulf of Mexico source: siencemag.org. 


While diesel is more fuel-efficient over long distances than petrol cars, the emissions they release are considered ‘dirtier’ than those from petrol. Diesel cars produce more nitrogen oxides (NOx) than petrol cars, which cause photochemical smog, which then leads to respiratory problems and aggravate asthma. Diesel cars also emit much higher particulate matter (PM) than petrol cars, a large contributor to climate change. Oh and they’re also a fossil fuel, just like petrol.


A comparison of petrol and diesel cars from www.air-quality.og.uk.

LPG (Liquid Petroleum Gas) and CNP (Compressed Natural Gas)

These two emit less carbon monoxide than petrol cars and relatively similar to the emission from diesel cars, but they are less efficient. They do however emit methane (MH4), which is approximately 25 times more potent than CO2. Like diesel cars, LPG and CNP also have lower levels of PM.

On paper LPG and CNP appear more environmentally friendly than petrol and diesel, but it is still a fossil fuel and it’s extraction from the earth is controversial, damaging and dangerous.

Vegetable Oil 

Vegetable oil can be used as a fuel in most diesel cars and is much more environmentally friendly option, especially if you recycle used oil (and you can often get this for free!). Unfortunately vegetable oil is not the panacea of car fuels though as the car may need modifications in order for it to run – making it more expensive, may cause damage if used incorrectly and generally needs more maintenance. My only concern with vegetable oil is that, if we all start converting our diesel cars to use vegetable oil then we may need to grow a lot more oil sources – such as palm, and this could wreak havoc and cause more deforestation than we’re already experiencing.

Electric Cars

The distinction between petrol/diesel and electric cars is not so simple to put into a three sentence paragraph. In fact, there is such a range, of which I include: hybrid, hybrid plug-n, range extender and pure electric, that it deserves it own post. Currently the market for electric cars is expanding so it’s definitely worth exploring as an option, however, realistically not in the immediate future (the Hyundai Iconic EV is valued at around $60k, of which I don’t have to spend on emerging technology right now). I will, however, be watching this space with immense curiosity and plan to write a future post on it!

Driving Audit – Where To From Here?

  1. Drive less overall, instead, opting for walking, cycling and public transport and eliminating unnecessary trips altogether. This extends to work as well, avoiding unnecessary external meetings and travelling by bike or public transport if unavoidable.
  2. Daily reminder that life is in fact not a round of Mario Kart, and I am unfortunately not Yoshi. i.e. drive more efficiently according to the pointers listed above.
  3. Be a more conscious driver – no wavering speed levels, change gears in time and slow down organically.
  4. Consider purchasing a diesel vehicle and running it on recycled vegetable oil. In the short-term, this is one of those situations that only displaces the problem, as my current petrol car will just be driven around by someone else. It will definitely be a consideration when the time comes for a new car.
  5. On that note, I would also consider an electric vehicle when upgrading, although this isn’t on the cards in the immediate future. What do we do with all the petrol cars if everyone makes the switch to electric cars, and what happens to the embedded energy?
  6. Advocate for government policy and subsidies for greener vehicles in Australia.



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