Save as you drive. Background information for expert fuel savers.

Transcription

1 Save as you drive. Background information for expert fuel savers.

2 Introduction Efficient motoring. How this brochure can help you save fuel. In an era of high fuel prices and climate concerns, it's not surprising that drivers are taking a new interest in fuel economy. Manufacturers' fuel consumption figures published in brochures and printed advertisements provide useful guidance when comparing the many different models. Since these standard figures form the basis for all the tips in this brochure, it's important to know how they are calculated. This introduction gives you the necessary background information. First of all, though, the most important thing to understand is that while fuel consumption is partly dictated by vehicle design and external factors beyond the driver's control like the weather, temperature or road surface these aspects are only responsible for around two thirds of your car's fuel consumption. The remaining one third is caused by factors that you the driver can influence quite easily, through the way you drive and use your car. And incidentally, anybody can become an expert fuel saver no matter what car they drive! The main influences on fuel consumption Energy conversion Engine: conversion of chemical energy into mechanical energy Mechanical energy losses Powertrain: gearbox, tyres, wheel bearings, power steering pump Engine: friction, combustion system, charge cycle Overcoming external resistance Weight Aerodynamic drag Air conditioning, cooling, electrical system Fuel consumption depends on many different factors. Some of these like the engine combustion system or mechanical losses cannot be influenced by the driver. But some of them can. For instance, every driver can do something to reduce external resistances, say by cutting payloads and aerodynamic drag or using auxiliary equipment only in moderation. 2 3

3 Introduction Introduction What you need to know. How fuel consumption figures are calculated. You want to save fuel? That's a good start! But to understand and track your progress, you first need to understand the official fuel consumption figures. These figures what you see in brochures, dealer showrooms or printed advertisements are based on a standard test of fuel consumption, the»new European Driving Cycle«(NEDC). What is the NEDC? The NEDC is a statutory test procedure for determining the fuel consumption of a passenger car or light commercial vehicle. This precisely defined test cycle is performed under laboratory conditions on a chassis dynamometer (test bench). NEDC testing of Volkswagen models is monitored and certified by the German technical inspectorate (TÜV). The fixed test parameters, which are the same for all manufacturers, include: Why does the same model have different NEDC fuel consumption figures with different gearboxes? The prescribed NEDC test cycle doesn't really do justice to a 6-speed gearbox. A 6-speed gearbox is generally lower-geared from 1st through 5th gear than a 5-speed gearbox. Since the gearshift points in the NEDC test are fixed, however, a vehicle with 6-speed gearbox will tend to run at higher rpm during the test. This generally results in a higher standard fuel consumption than when the identical engine is tested with a five-speed gearbox, despite the fact that, in real-world driving, a 6-speed gearbox can often be more economical. How relevant are the NEDC figures for your personal fuel consumption? The NEDC figures are an excellent tool for comparing the fuel consumption of different cars and for obtaining general information about the fuel consumption of an individual model. Three NEDC figures are calculated for every model: the»urban«,»extra-urban«and»combined«figures. Anyone who does most of their driving around town should refer to the manufacturer's»urban«figure, and should not expect to achieve the combined figure. That said, the NEDC information does not provide an accurate guide to the fuel consumption that will be achieved by the individual driver, since everyone's driving profile is different. So by applying the tips given in this brochure, you may even be able to improve on the manufacturer's NEDC figures. ambient temperature payload cold start gearshift points start of sampling all auxiliary consumers switched off However, no standardized driving cycle in the world can tell drivers precisely what personal fuel consumption they will achieve in practice, because every journey and every driver is different. Certificates like this one must be displayed on any new vehicle offered for sale in a dealer's showroom. They contain information on model, CO 2 emissions and NEDC fuel consumption. The certificate on the left is for a 90 kw Golf 1.4 TSI with 6-speed manual gearbox. This model is the example used for all figures, calculations and tips in this brochure speed (km/h) speed (km/h) Fuel consumption of a Golf 1.4 TSI (6-speed) in relation to distance and time urban 8.2 l/100 km extra-urban 5.1 l/100 km combined 6.2 l/100 km fuel consumption fuel consumption fuel consumption (l/100km) distance (m) 12 fuel consumption speed fuel consumption gears 2 1. fuel consumption (l/100km) time (s) speed NEDC fuel consumption is calculated in a 20-minute test on the chassis dynamometer over a simulated distance of 11 kilometres. A prescribed series of accelerations and decelerations causes fuel consumption to rise and fall as shown. urban 8.2 l/100 km extra-urban 5.1 l/100 km combined 6.2 l/100 km Test in accordance with EU Directive 80/1268/EEC: T=20 C, all auxiliary consumers switched off. 4 5

4 Fuel-Saving Tips Fuel-Saving Tips When it's time to say no. Avoid short trips. There are savings in the air. Check your tyre pressures. Your engine is not fully efficient until it has warmed up to operating temperature, allowing the lubricants and fluids to perform at their peak and keep engine friction to a minimum. This means that very short journeys, made from a cold start, cause relatively high fuel consumption, well above the standard NEDC combined figure. So the best way to save fuel is to combine those short runs to the newsagents, the post office or the local shops into a single trip. In cold weather, short trips waste even more fuel. When outside temperatures are low, fuel consumption over the first four kilometres can be as high as 30 litres per 100 km less than 8 mpg! And incidentally, idling the engine to warm it up is not only against the law in some countries, it is also unnecessary and a waste of fuel. Imagine a patch of rubber about the size of a postcard that's how much of each of your tyres is transferring power to the road at any one time. Despite that, the rolling resistance of this»contact patch«or»footprint«accounts for approximately 10% to 15% of your total fuel consumption. At 20 km/h, rolling resistance accounts for almost all the external resistance acting on the car, and it still accounts for 60% of total resistance at 50 km/h. A big factor in rolling resistance is tyre pressures: if you're just 0.2 bars off the ideal pressure, you're already adding 1% to your fuel bill, due to increased rolling resistance. Tips: Check your tyre pressures, when the tyres are cold, at least once every three to four weeks. Even when your car is not fully loaded, keep your tyres inflated to the recommended full load pressures (for the price of a slight drop in comfort). In your Volkswagen, you'll find the recommended pressures inside the fuel filler flap. Every journey is different. For a 10-km trip, a difference of 20ºC in outdoor temperatures (roughly the difference between summer and winter temperatures) can make a 20% difference to your fuel consumption. And if you normally travel not 10 km but just 2 km, that can increase your personal fuel consumption by as much as 50%. One of the criteria when Volkswagen selects the original tyres for your car is minimum rolling resistance. Since potentially that could conflict with other priorities such as braking performance, the best tyre will be the one that achieves the best possible compromise between all the required criteria. All BlueMotion models are factory-fitted with low-rolling resistance tyres. These tyres reduce fuel consumption by up to 3%, without compromising safety. Once again, you the driver also have a part to play. When you need to replace your tyres, be sure to choose tyres with reduced rolling resistance. Fuel consumption in % (versus NEDC baseline) winter ( 9 C to 5 C) At an ambient temperature of 1 C to 5 C, the rate of fuel consumption reaches the NEDC combined value after approximately 10 km. 100 Rolling resistance is generated by deformation of the tyre as it rotates over the road surface. This»flexing«consumes energy. The larger the tyre area in contact with the road, the greater the rolling resistance. The coefficient of rolling resistance is a measure of how much rolling resistance a tyre produces. summer (11 to 15 C) Exactly how a tyre impacts on fuel consumption will depend on its diameter and width, the type of rubber compound used and the tyre tread Distance (km)* For example, the rolling resistance of tyres with a diameter of 225 millimetres is 6% higher than that of 185-mm tyres. * A typical journey 6 7

5 Fuel-Saving Tips Fuel-Saving Tips Oiling the wheels of progress. Use fuel-efficient engine oil. Go lightly on the fuel. Avoid unnecessary weight. Low-viscosity synthetic engine oils may be slightly more expensive, but they can cut fuel consumption by as much as 5% by reducing internal friction and circulating better and more quickly around the engine, particularly when starting from cold. The biggest savings can be achieved on short trips and around town. Almost every new Volkswagen leaves the factory with a first-fill of long-life low-viscosity oil. Remember that every kilogram you transport costs you fuel. An extra 100 kilos can increase your fuel consumption by up to 0.3 l/100 km, depending on how you drive, and produce up to 7 grams more CO 2 per kilometre. That's why Volkswagen has adopted a wide range of measures to make its vehicles as light as possible, despite ever more stringent demands on comfort and safety. Here are some examples: Always make sure your car has enough oil, and observe the recommended oil-change intervals. That way your engine can do its job efficiently and keep emissions down. And if you do have to top up your oil, be sure to check the owner's manual to see which oils are approved for your car. You will be able to prolong your oil change intervals to as much as two years if you use only these products. Their specifications match the current Volkswagen engine range and they have excellent long-life characteristics. use of hot stamping, to produce high-strength sheet metal which is also extremely lightweight use of lightweight plastic or natural fibre materials in the underbody tray and spare wheel well use of light alloys wherever this makes sense Tire Mobility Set with this repair kit for the quick and easy repair of minor punctures there is no need to carry a spare wheel, saving additional weight use of steel wheels with optimised material thickness. Tip: One way to avoid squandering these inbuilt savings is to regularly»declutter«your boot. Filling stations are so plentiful nowadays that it's pointless to travel around with a full fuel canister. There's no need to carry around five old issues of your road atlas either, or a 10-litre can of antifreeze. Low-viscosity oils are extremely thin-bodied engine oils containing very high-grade additives. Their low viscosity ensures excellent engine lubrication even at low temperatures and when starting from cold. You can always tell low-viscosity oil by the viscosity number 0 or 5 that appears in front of the letter W in the classification. A further feature of low-viscosity long-life oils is that their base oils are more oxidation-stable, more temperature-stable and slower to thicken. One of the weight-saving techniques used in production of the Golf and the Passat is hot stamping. Only in the narrowest sense is hot stamping a more energy-intensive production process than conventional hardening. Because the higher strength of the resulting sheet metal means that less steel is required per vehicle reducing the weight of a Passat body by about 20 kilograms, which in turn reduces fuel consumption. The lower weight is also reflected in lower total lifecycle CO 2 emissions. In the Golf, hot-stamped sheet metal is used in the A- and B-pillar linings and in structural components. Intelligent lightweight manufacturing. 8 9

6 Fuel-Saving Tips Fuel-Saving Tips Streamlined savings. Use the fuel-saver lever. Think aerodynamic. Change up early. The less wind resistance your car offers the better. A Volkswagen's aerodynamically designed bodywork reduces wind resistance to a minimum. But if you pile on the luggage racks, roof boxes and cycle racks, those built-in benefits can all too quickly be lost. Just fitting a ski rack to your roof increases aerodynamic drag by 33.3%, which will: increase your fuel consumption by more than 0.8 l/100 km at 100 km/h. increase your fuel consumption by more than 2 l/100 km at 160 km/h. Tip: If you're going on holiday, it may actually prove cheaper to hire bicycles or skis at your destination, rather than taking them with you on a roof-rack, particularly if you face a long journey on the motorway. Obviously, when rooftop fittings are not in use, be sure to remove them at the first opportunity. And don't forget that open side windows are a further source of turbulence, reducing aerodynamic efficiency by more than 7%. That can add a further 0.3 l/100 km to your fuel consumption when travelling at 130 km/h. A higher gear is always a more economical gear. So for most cars the general rule is to: change up into third at 30 km/h, into fourth at 40 km/h and into fifth at 50 km/h. You won't hear your engine complain about running at low revs. Our state-of-the-art TDI and TSI engines are very responsive even below 2,000 rpm. And the innovative dual-clutch gearbox invariably shifts through the gears with perfect timing, all by itself which is why it is around 10 to 20% more fuel-efficient than a conventional automatic transmission. In the BlueMotion models, your fuel efficiency is also helped by higher gear ratios, while the gear-change recommendation in the multifunction display will always let you know the ideal time to change gear. Tips for manual gearboxes: Don t rev too high in each gear before changing up. Use first gear just to get the car moving and change into second once it has moved through its own length. And if the traffic situation permits, you can skip a gear as you change up, shifting from third into fifth for example. Tips for automatic transmissions: avoid activating the kick-down feature. By lifting off the accelerator briefly you can get the transmission to shift up earlier, which will save you fuel. On the road Remember that speed is a big contributor to aerodynamic drag. If you double your speed, drag will increase four times over. The graph clearly shows how changing up early can save you fuel., at a speed of 50 km/h, our typical Golf consumes 1.2 l/100 km more fuel in 3rd gear than it does in 5th. Additional fuel consumption (l/100 km) 2,4 2,2 2,0 1,8 1,6 1,4 1,2 1,0 0,8 0,6 0,4 0,2 Roof box Ski-rack Roof rack Open front side windows Fuel consumption (l/100 km) st gear 2nd gear 3rd gear 4th gear 5th gear 6th gear Speed (km/h) Speed (km/h) Fuel consumption curves in each of the six gears for 90 kw Golf 1.4 TSI, at 20 C ambient temperature 10 11

7 Fuel-Saving Tips Fuel-Saving Tips Target zero fuel consumption. Just let it roll Take a farsighted approach. Go with the flow. Coasting in gear cuts off the fuel supply to the engine. This is also referred to as overrun cutoff, and it means you're not using a single drop of fuel. This is different from coasting with the clutch depressed, when the engine continues to tick over which means it is still burning fuel, albeit in very small quantities. You can easily compare your fuel consumption when coasting with the clutch depressed and when coasting in gear. Just set your multifunction display to»current fuel consumption«and you can see for yourself the effects of overrun cutoff. On average, every seventh litre of fuel is consumed in stop-go traffic conditions.»going with the flow«which means more coasting and less use of the brake and accelerator will save you fuel. Tip: Always keep an adequate distance from the vehicle in front. This will help you maintain a smooth driving style and will also help reduce congestion. Use overrun cutoff when: you want the engine to help you brake, for example when approaching a red traffic light, or when you're on a steep downhill gradient. Using the braking effect of the engine will also reduce the wear on your service brakes. On the road But depress the clutch when: you want to maintain a constant speed on a long, level stretch of road, or to coast to a stop, or when you want to maintain or increase your speed on a gentle downhill gradient. The biggest fuel savings with overrun cutoff are achieved around town. On the road As soon as you lift off the accelerator with the car in gear, the engine management shuts off the fuel injection and your consumption falls to zero. This fuel-saving habit is built into your Volkswagen and is automatic every time. Actually switching the engine off while the car is moving, a habit popular with more extreme members of the»hypermiling«movement, is not only very dangerous, there is no technical justification for it either. It does make sense to switch off at a red light or a level crossing, though, if you have to wait more than 20 seconds. If your vehicle has a stop/start system, the engine will stop and start automatically, bringing further economy benefits. Because for every three minutes the car spends idling when stationary, it uses as much fuel as it would to drive one kilometre at 50 km/h. 1/2 h at 100km/h Constant speed of 130 km/h The benefits of driving at a constant speed are most apparent on the motorway. If you travel for half an hour at 100 km/h, followed by half an hour at 160 km/h, you will consume 0.4 litres more fuel than someone who travels at a constant 130 km/h for the whole hour. And at the end of that hour, both drivers will have travelled exactly the same distance. 1/2 h at 160 km/h fuel consumption 7.5 l fuel consumption 7.1 l Distance 130 km: journey time 1 hour 12 13

8 Fuel-Saving Tips Fuel-Saving Tips Be cool, save fuel. At a glance. Make moderate use of auxiliary consumers. The fuel-saving potential of the different tips. Comfort may be important, but you can overdo it. For example, cooling the interior to 18 degrees when it's 30 degrees outside means hard labour for the air conditioning and increases your fuel consumption quite apart from the fact that if you set interior temperatures way below the outdoor level, you and your passengers risk catching a cold. That said, an agreeable interior temperature will improve the driver's concentration and thus safety. But remember: even when it's only trying to maintain a steady temperature particularly at low speeds the air conditioning can raise fuel consumption by as much as 2 litres/100 km. Other electrical consumers too, like seat heating, the telephone or the rear windscreen heater, all add to your fuel consumption. Because the power they use comes from the car battery, and to replace that consumption the battery has to be recharged by the engine, via the alternator and V-belt. True, the benefits of a fuel-saving style of driving can't be quantified to the last penny or cent, but our Fuel-Saver courses over recent years have provided a very good approximation. Depending on your original (baseline) style of driving, you can cut your fuel bill by as much as 25 percent without having to drive any slower. For drivers of a 90 kw Golf 1.4 TSI with an annual mileage of 20,000 kilometres, that adds up to savings of approximately 460 euros a year (based on a fuel price of EUR 1.50 per litre). Do you mainly drive around town commuting to work perhaps? Or do you do most of your driving on the motorway? The tables below show which tips are most valuable for which type of driving. Tips: On the motorway air the car before you set off, then leave the windows open Avoid short trips for a while before switching on the air-conditioning. Or: Check your tyre pressures use the A/C in recirculation mode to begin with, so that you are Use fuel-efficient engine oil only cooling the hot air inside the car, not hot air from outside as well. Avoid unnecessary weight Think aerodynamic And incidentally, at colder times of year, be sure to switch off the automatic climate control, otherwise the compressor will continue to run unnecessarily. In this situation, the most fuelefficient option is to switch to normal ventilation mode. On the road Change up early On the road Just let it roll Go with the flow Make moderate use of auxiliary consumers Auxiliary consumers use fuel! Interior fan, min. Interior fan, med. Interior fan, max. Rear windscreen heater Heated mirrors Seat heating 0.08l/100 km 0.36 l/100 km 0.51 l/100 km 0.30l/100 km 0.04l/100 km 0.36 l/100 km 14 15

9 Fuel-Saver Courses Fuel-Saver Courses Take a fuel-saver course. Experience the benefits for yourself. Enjoy driving responsibly. Fuel-saver courses save money and help the environment. Interested? Great! One way to put fuel-saving theory into practice and actively save money at the wheel is to sign up for one of the Fuel-Saver (eco-driving) courses that Volkswagen stages across Germany. As part of the»volkswagen driving experience«, professional instructors will advise you how to save fuel and give you tips geared to your own personal style of driving. A training session looks something like this: first, at the wheel of a Volkswagen provided by us and with a professional trainer at your side, you will be asked to drive a specified route under normal traffic conditions and in your normal driving style. Selected data such as fuel consumption, CO 2 emissions, rpm and driving time will be recorded on a special trip recorder along the way. At the end of this first drive, your trainer will then explain what you can do to improve your fuel efficiency. Then you will be asked to drive the same route a second time, this time following your trainer's instructions. Afterwards, the two drives will be fed into our»moderndrive«analysis software. This is where you get the final confirmation that by applying the fuel-saving tips you can make substantial fuel savings and still be just as quick from A to B. For further information about Fuel-Saver courses call our toll-free number +49 (0) or consult our website at: Since 2004, Volkswagen has been organizing free(!) Fuel-Saver courses in cooperation with the German Society for Nature Conservation (NABU). Last year alone, over 1,500 drivers were able to achieve up to 25% fuel savings after attending these courses but that wasn't by driving more slowly. Far from it: often their average speed actually increased! Volkswagen Fuel-Saver courses not only make driving more enjoyable and save money, they also benefit the environment. German Transport Minister Wolfgang Tiefensee has praised them as:»a great idea, with great potential.«true enough: based on their total annual mileage, if all German car drivers were to take these courses, 12 million tonnes of CO 2 could be saved every year that's approximately 1.3% of the country's total CO 2 emissions. What they say about our Fuel-Saver courses:»a great idea, with great potential.«wolfgang Tiefensee, German Minister for Transport, Construction and Urban Development»Amazing how much further you can stretch your fuel. Super!«Dr. Reinhard Loske, Bremen's Senator for Environment, Construction, Transport and European Affairs»To achieve so much with so little effort that's got to be good!«hans-heinrich Ehlen, Lower Saxony's Minister for Food, Agriculture, Consumer Protection and Regional Development Eco-driving in a Golf Route: 6 km, 90% urban, 10% extra-urban Baseline drive With tips Savings Journey time 0:10:52 0:10:20 Av. engine speed 1,581rpm 1,320rpm Av. speed 33.8km/h 35.4km/h Av. fuel consumption 6.90l/100km 5.52l/100 km 1.38l/100 km Trip consumption 0.42l 0.34l 0.08l Trip CO 2 emissions 1,103kg 0,884 kg 0,219kg Want to cut your fuel consumption by up to 25%? Free Fuel-Saver courses at selected Volkswagen dealerships across Germany will show you how it's done

10 Have fun! Congratulations! If you're driving a Volkswagen you are already driving a very economical and environmentally compatible vehicle. But by applying the fuel-saving tips in this brochure, you can make your fuel go even further. And save yourself a lot of money into the bargain. Money you can spend on the really important things in life. Like a family holiday, or visiting friends or maybe just a trip to the seaside. Whatever you have in mind, Volkswagen hopes you have fun! For further information, please visit us at: PS: The essential tips above can also be found in a handy, glove compartment-sized brochure called»fuel-saving tips for your Volkswagen«available from your local Volkswagen dealership. Thermische Abluftreinigung einer Lackiererei

11 Volkswagen AG Group Research, Environmental Affairs Product D Wolfsburg, Germany March 2009 Article No