Difference between revisions of "Fuel Consumption"

Latest revision as of 17:14, 31 January 2009

One of the most common questions asked by prospective buyers of Discovery 3 is how many Miles Per Gallon will the vehicle do. This depends very much on style of driving on any given journey as well as any modifications to the vehicle. Please note, all below figures are based on the TDV6 diesel engine.

Government official fuel economy figures:

Urban: 24.5 MPG

Extra Urban: 34.5 MPG

Combined: 30.0 MPG

For Automatic vehicles, fuel consumption increases on average by around 2-3 MPG.

However, driving style can impact Discovery 3's fuel consumption figure heavily. Searching the Forum for 'Fuel Consumption' will turn up over 10 pages of discussion of different members' claimed figures. However, what can be gathered from several posts is that very different figures from the Government officials' can be attained if driving to a certain style. The below figures are said to be achievable based on members' experiences.

'Real' economy figures:

• Motorway: 70-75mph - very careful and precise driving (see 'How to save fuel' below) - fairly long distance - 34-36 MPG
• Country Roads: Careful driving (see 'How to save fuel' below) - around 60mpg - 27-30 MPG
• Varied Driving: Equal blend of motorways, country roads and city driving - 26-29 MPG
• Careful Urban Driving: Very careful urban driving (see 'How to save fuel' below) - 23-25 MPG
• Urban Driving: Stop-start driving - heavy traffic - no consideration to fuel economy - 20-21 MPG
• Towing a caravan or heavy trailer: Motorway cruising - 24-26 MPG
• Off-road driving: Special Programmes on - low range gearbox etc. - 18-20 MPG

This figure was achieved by a member driving over 30 miles at 50mph for over 30 miles

Note:

These are all approximate figures and can change dramatically between drivers, however they should provide a rough guideline as to how much fuel you can expect the Discovery 3 to consume. With concentration and thought towards saving fuel, all of these figures are likely to increase.

Figures are said to drop by around 2 MPG in the winter when the FBH consumes fuel.

Adding off-road accessories (such as roof racks, raised air intakes, winches and mud-terrain tyres) will increase your Discovery 3's fuel consumption.

Some vehicles have 'chipped' engines. This may impact fuel economy in both positive and negative ways.

How to save fuel:

• Do not accessorise your vehicle unnececessarily.
  • Roof racks, air intakes and protruding auxilary lighting reduce the smooth air flow over the vehicle, and off-road tyres require more energy to move the vehicle, consuming extra fuel. A winch weighs a significant amount therefore uses significantly more fuel to carry it. An un-used roof rack will worsen fuel economy by at least 5%.

• Do not use electronics when they are not necessary.
  • Air conditioning, heated seats and windows will incrase fuel consumption by aruond 10%. However, when above 60mph, it will use less fuel to have your A/C on than to lower the windows.

• Drive in the right gear for your speed. Move up to a higher gear when the engine can cope with it.

• Avoid high speeds.
  • Stick to 70mph on the motorway. Around 50% of the engine's power is overcoming aerodynamic drag - above 70mph drag increases significantly so extra fuel is consumed.

• Drive smoothly.
  • Accellerating and stopping takes most of the fuel. Maintain a steady speed when possible, and accellerate and decellerate from traffic lights slowly and progressively.

• Don't open your window, especially at fast speeds.
  • This causes major drag thus increases your fuel consumption.

• Keep tyres pumped to the correct pressure.
  • Tyres which are underinflated have a greater resistance thus use more fuel to move.

• Regularly change your oil.
  • This will reduce friction from moving parts of the engine.

• Reduce unnecessary weight.
  • Remove clutter such as golf clubs and bags etc. which can be stored inside. Every 50kg of extra weight will increase fuel consumption by approximately 2%.

• Shop around for cheaper fuel prices.
  • Visit PetrolPrices.com, sign up for free and find out where the cheapest garage near you is for fuel.

• Fill up your tank either very early in the morning or in the evening.
  • Fuel becomes denser in colder temperatures, and fuel pumps charge you for the volume of fuel you extract and not the density. You get more fuel for your money.

• Fill up at busier garages.
  • If you have time to wait, busier garages require their tanks to be re-filled more often, on a regular basis, whereas quieter garages may have fuel sitting in pumps for longer amounts of time. This will reduce the quality of the fuel.

• Avoid driving on rough roads.
  • Eg. gravel or heavy dirt. These surfaces can increase your fuel consumption by around 30%. Even if the tarmac route is a longer distance the reduction in friction will usually save you more fuel. Obviously this is only when you are not off-roading.