10 Tips That May Help You Save Fuel

Even as internal combustion engines are becoming ever more powerful, use of state-of-the-art technologies also means they require less fuel. Nevertheless, a lot depends upon how we drive. Careless driving may increase average fuel consumption by several litres, even though you do not substantially boost your average speed. You can save a lot on fuel by following these ten rules.

2. 11. 2017 Škoda World Innovation & technology

1. Get rid of useless loads

Every kilogram of a useless load increases fuel consumption, even if just a little. Make sure to always take out unused child seats and forgotten pieces of luggage. Even more importantly, remove bike/ski carriers (or the whole box) from the vehicle whenever you do not need them. Besides extra weight, these items substantially increase the aerodynamic resistance that affects the fuel consumption even more, to say nothing about the noise generated by such objects.

2. Do not deactivate the Start-Stop system

Start-Stop has a positive effect on fuel consumption. Deactivating this system does not make much sense: ŠKODA engines are completely prepared for it and designed to ensure that frequent starts do not affect their lifespan. A small tip as a bonus: when you have to stop and wait for a longer time, for example at a railway crossing, switching the engine off completely (whether with the on/off button or using the key) may pay off, because otherwise the Start-Stop system will start the engine automatically in a few minutes. The reason is that after a few minutes of inactivity the car runs out of the energy used for the various in-car devices and onboard systems.

3. Set out for the trip right away rather than letting your car warm up while stationary

Do not warm the engine up on idle, because in this mode the engine warms up slowly, as it is not required to generate any other power output than that sufficient for self-propulsion and its temperature therefore increases very slowly. It is much better to set out for the trip right away and do the first few miles with a light foot. Only a properly warm engine achieves optimum fuel consumption levels, and this way you will not only safe fuel but also increase the engine’s lifespan.

5. Check the tyres

Although the TPM system (Tyre Pressure Monitoring) in ŠKODA tyres will do this job for you, it is still useful to check the tyre pressure from time to time, because the TPM sometimes fails to notice minor pressure losses and even such a minor decrease in pressure may have negative effects on the driving properties and fuel consumption. If you are getting ready for a holiday trip and your plan is to load the car well above its usual average, you had better inflate the tyres for maximum load – the required-pressure data are usually provided on a label placed on the inside of the fuel filler neck lid. If you fail to do this, the TPM will not indicate any pressure loss, but mainly your rear tyres are likely to be actually underinflated. Besides fuel consumption, this aspect has a negative effect on the car’s stability in motion… and therefore safety.

8. Be aware of energy eaters

Air conditioning is a great invention, but you don’t have to use it all the time, do you? With the AC switched on, your fuel consumption increases by as much as 1 l/100 km, particularly in vehicles fitted with manual or semiautomatic AC systems; automatic air conditioning systems are more energy-efficient. On the other hand, substituting the air conditioning by opening the windows is not smart, either, because open windows substantially increase the car’s aerodynamic resistance and therefore its fuel consumption. Besides air conditioning, you should also use the seat, window and mirror heating reasonably, as these are also energy “eaters”. Specifically the mirror heating switch should not be kept “on” permanently – if it is on, every start comes with a useless energy load, although the mirror heating function is often completely unnecessary.

9. Use cruise control correctly

Cruise control is a useful tool that may help you reduce your fuel consumption substantially by stabilising your speed. Yet you’d better rely on your right foot in hilly landscapes with frequent ascents and descents, because pushing some more gas in and therefore moderately accelerating when going downhill will give your car enough inertia for the upcoming uphill stretch. In contrast, the cruise control tends to brake the vehicle when going downhill, and then, to maintain the same average speed, the engine load increases and the fuel consumption goes up, too.

10. Use the gear-change advisor

Applies to manual-gearbox cars. Every ŠKODA vehicle is fitted with a gear-change advisor, and you will benefit by actually using it, because the system is designed to help you always use the best gear and thus avoid over-revving or under-revving the engine. Modern downsized engines provide enough power even at surprisingly low revolutions. You may have noticed that when the car cruises while you basically do not depress the accelerator pedal, the advisor prompts you to gear up; as soon as you depress the pedal, the upwards arrow disappears – this is because gearing up is no more the best way of meeting the need for higher output.

ŠKODA vehicles fitted with the 1.4 TSI ACT and 1.5 TSI Evo engines (the latter is making its debut in the KAROQ) have been using the automatic cylinder deactivation system since 2015 (ACT stands for Active Cylinder Technology).

The system gets activated automatically whenever the engine speed gets between 1,400 and 4,000 revs/min and the vehicle cruises at a stable speed, under a partial load, i.e. usually on flat or downhill stretches, and on condition that the speed does not exceed 130 km/h.

In such circumstances the vehicle needs a very low power output and low torque levels (approximately 25 - 100 Nm) that can be reliably provided by just two cylinders instead of four. By disconnecting the supply of air and fuel to the second and third cylinders, the system reduces the inner engine resistances and the engine therefore operates more economically. Depending on the driving style, the ACT can save as much as 0.5 l/100 km. The system’s activity is indicated on the dashboard, and the ACT indicator is actually the only thing to let the driver know that two cylinders have been deactivated, because they won’t feel any “physical” difference.

How much have engines changed over the last decade in terms of their economy?

Achieving the maximum possible efficiency and economy of combustions engines is one of ŠKODA’s primary goals on the engine development side. This goal can be accomplished by optimising the combustion process, minimising inner losses and resistances and partially electrifying the system while minimising the exhaust gas emission levels. The results of development efforts in these areas are used in modernising the existing series-production engines as well as in launching series production of new engines.

For example, we have recently made regulated oil pumps and engine oil systems part of our series production, which has a positive effect on inner engine resistances; series production engines feature multi-circuit cooling systems with multi-level temperature control, which has a positive effect on the engine’s overall temperature parameters; fuel injection pressures are increased for higher combustion efficiency; we use the recuperation capacity of electrical energy sources to improve vehicles’ overall electricity parameters; we have implemented the Start/Stop system, and turbochargers are now used extensively also in the smallest engines.

Karel_Franz_výřez — **Karel Franc**
ŠKODA Head of Engine Development

Ten years ago we had the EURO 4 emission standard under which the OBD (On-Board Diagnostics) standard entered into force. These days we have EURO 6 which was established three years ago and has been made stricter several times ever since. Stricter emission regulations go hand in hand with growing demands placed on the quality of fuel – this quality has to be guaranteed by governments. The list of measures could be much longer, these are just some examples. And we also need to bear in mind that fuel consumption is not only about the engine. We need to optimise the whole vehicle in terms of weight, rolling resistance, aerodynamics, front area and, of course, transmission system efficiency.

What does the driver have to do to make full use of the high-economy potential offered by modern engines? What are the key rules of economical driving with these engines?

The efficiency of combustion engines is not constant throughout the revs-and-load range. Put simply, to achieve fuel savings, it is better to keep the revs lower and the load higher, i.e. gear up at lower speeds than what was considered standard in the past. The gear-change advisor may help - every new ŠKODA is now fitted with this system.

Modern engines are designed for these operating modes (and tested accordingly), and they achieve optimum fuel consumption and gas emission levels in them, i.e. there is no need to worry about their lifespan. These operating modes are particularly suitable for modern supercharged engines that provide enough power already at rev levels close to idle. Revving the engine high and changing gears in the maximum-power area is certainly not recommended in terms of fuel consumption. These modes are designed for short-term use of the engine dynamics, e.g. when overtaking, but are nowhere near the optimum in terms of driving economy.

Can combustion engines become even more economical, or have we used up their potential and the future belongs exclusively to hybrids and electric vehicles?

The technological potential offered by combustion engines has not been used up yet. There is a number of technological solutions and principles that have been known for a long time but only the latest technological developments (including electronics) make it possible to use such solutions in future series-production engines. Examples include highly variable valve timing control and variable compression ratio.

These solutions require a combination of state-of-the-art mechanical engineering technologies and powerful electronics that can effectively control the combustion process in the engine. This way we are increasing the efficiency of operation of the combustion engine while reducing the emission levels and maintaining the power output parameters as well as user comfort levels. Personally, I believe that the future of car engines lies in an optimum combination of benefits posed by combustion engines and electric motors. Each of these technologies offers benefits in some operating modes, and its utilisation depends, among other things, on the user’s requirements.