Let’s be honest: who has never sweated it out trying to make it to the next petrol station, whether you made it or not? When the time comes, which it will sooner or later, do you know what to do if you‘re not sure you’re going to make it? How to calculate exactly how many miles you’ve got left in your tank? And, of course, the most important question: how to ride more efficiently so as to use less petrol? In this article we’ll try and give you a few pointers that could be useful in those cases where the petrol is running out, due to our absent mindedness or because the petrol station that we hoped to find open was closed or abandoned….
To start with, we should go over the factors that most affect our petrol consumption when riding our bike:
Maintenance: Many mechanical aspects, that should be checked regularly, directly affect the consumption of our machines. The most classic one is tyre pressure, as if it is too low, apart from the safety issues, it will negatively affect our consumption and autonomy. But there are other aspects to bear in mind like filters, spark plugs, chains, valves, idle speed, as well as the age of the engine or the miles accumulated. All these have a negative effect if you don’t take regular care of your bike.
Aerodynamics: One of the most important points when calculating mileage is our wind resistance. And it is when the bike-rider unit offers less resistance that the autonomy increases considerably. There are many factors that influence this, like, for example, our own constitution, the type of bike we have, the riding position, the side cases, the protective screen, the front mudguard, the hand covers and many other details than can also put up more or less resistance. Even the silhouette of the helmet can influence the way the wind flows around us and, in fact, is cause for study for most manufacturers, who dedicate much time to achieving helmets that are more and more aerodynamic. What’s more, practically all motorcycle clothing takes these aerodynamic aspects into account, being evident in the design of gloves, boots and jackets, especially if they are for touring or sports use.
Despite what we’ve seen up to here, not everything is in our hands: many other factors influence our bike’s mileage. To start with, not only can the wind benefit or penalise our petrol consumption, but so can atmospheric pressure, humidity and temperature, especially in the case of bikes with carburettors. The weather conditions, therefore, can make the autonomy of our machines vary slightly, similar to when we notice that some engines don’t work exactly the same in winter as in summer, or at night as in the morning, etc.
Of course, the slope of a road can very much affect us on the bike, the difference in consumption being very significant between riding 100 kilometres uphill or downhill, even with the same constant speed in both cases. Also, a road full of pot holes can also use up more petrol as it doesn’t let us maintain a constant speed, apart from the obvious inconveniences of roads in bad conditions.
Engine and rider
As regards the engine, there are classic factors that affect petrol consumption: power, torque and cubic centimetres, as well as the number of cylinders and their placement, the power curve, the ratio of the gear changes or the continuous variable transmission, the sixth overdrive and the speed controls in powerful touring bikes, etc. This in itself, even though it seems obvious, has a myriad of nuances. Each engine is a world in itself and requires a degree of understanding by the rider in order to improve its efficiency. With practice, anyone can reduce their average consumption if they really put their mind to it.
Having said that, whatever the bike and its engine, it’s not just the type of riding performed but the constitution and weight of the rider that are also very determinant factors. In fact, some studies have shown that two riders, with a weight difference of almost 40 kilos, can achieve exaggeratedly different autonomies on the same bike and at a similar speed. Of course, the heavier rider is usually more voluminous, which will also negatively affect the bike’s aerodynamics.
Type of road
Why do I get less mileage around town even though I’m going slower? Do you really use more petrol on the motorway? To start with, it’s clear that the same tank can be used up in a thousand different ways according to where and how we use it up. For example, cities are an area where having to set off from being stopped, the stopping, the waiting, the jams and other factors use a lot of petrol. The heavier and more powerful the bike, the greater the difference between urban and road riding.
However, it’s not that evident that the motorway is where we could stretch out our fuel. Generally, a constant rhythm, within the legal limits, should be enough to save us much fuel as the bike will allow us. And that is true. What happens though, is that an efficient and intelligent ride on very winding roads can give us the opportunity to get even better mileage than on the motorway. Why? Simple: normally between entering a curve and exiting it, we don’t normally accelerate, at the most a touch of throttle just to correct the line and face the bend better. That is to say, that whilst going round the bend, the bike travels and adds kilometres thanks to its inertia, being able to circulate at a normal rhythm using very little fuel. It’s surprising how much more autonomy you can get if along your route there is a good stretch of winding road.
And not only this, in these cases the speeds are usually lower than when on the motorway, instead of a steady 120 km per hour, on winding roads we usually go between 40 and 100 km per hour, which very much affects our consumption. Nevertheless, for this to be true, we have to be very gentle when coming out of a bend, use the appropriate gear and without sudden accelerations. Without a doubt, this is a good way to enjoy your bike: curves and more curves and to top it off, saving petrol!
In this section we also have to take in to account that a bike in retention, i.e., not giving it throttle and going down the gears where appropriate, uses les fuel than when ticking over in neutral or with the clutch pressed, which, apart from not being recommend, is also dangerous. In engines with carburettors, (the injection already takes this into account) it is sometimes better to gently accelerate in a lower gear than a higher one that makes the revolutions go up too slowly. So, at those times where the engine does not breathe easily, it jolts and does not respond well to the throttle, it is better to go down a gear then insist, as we’re using up a fuel that hardly provides more engine revolutions.
I’ll have to draw out what I have left…
As in all situations, if we’re on the verge between making it or not to the next petrol station, there’s nothing left but to act in the following way if we want to save those drops of petrol that might make the difference: on the road for example, we must fit ourselves to the bike as much as possible in order to provide less wind resistance, with our elbows and knees tucked in, obviously such that this doesn’t interfere with our safety or confidence when riding. And always being gentle and progressive with the throttle.
Running out of petrol around town is maybe not so serious, as it is easier to just leave the bike safely and get to the petrol station by some other means. Even so, it is important to anticipate red traffic lights and leave off the throttle sooner so that we reach the light with our own inertia. This also saves on brake pads. On the other hand, if you feel that the petrol might run out in the middle of a winding road, it is of vital importance to think of a safe place to leave the bike without placing other drivers at risk. You must bear in mind that, at night, our bike parked on the side of the road can be virtually invisible and might provoke an unnecessary scare. What’s more, we could be fined for generating a dangerous situation. To this end, many bikes and scooters have parking lights for just these cases and with minimal battery consumption, making the bike visible for hours.
Also, there are some tricks that can help us. For example, filling up at the coolest time of the day can give us a little petrol plus by obeying the laws of physics that state that fuels tend to expand with heat. More important though is to check the real mileage you get from your bike with your riding. It’s as easy as using a partial milometer and a calculator: fill up with petrol, set the clock to 0, ride as usual and the next time you fill up you can see exactly how much petrol you need to fill up (which is how much you’ve used) and the kilometres travelled. Even more, it’s a good idea to do this exclusively for town driving and then for just road or motorway use. This way you can make much more accurate previsions.
If, in spite of everything, you run out of petrol, there are various options. In town, the most probable thing to do would be to go on foot to the nearest petrol station and get petrol in a special receptacle for these types of emergencies. And, on the road, the first thing would be to leave the bike as far to the right as possible on the hard shoulder, try and signal it off correctly and promptly call for assistance. It is possible that your insurance doesn’t cover these cases and they might make you pay for the service, another reason to be extra careful when controlling fuel levels.
Finally, remember that running out of petrol could result in an administrative fine if you generate a dangerous situation for other drivers. Even so, don’t panic! The motorcycle brands always round up their numbers, so it’s quite likely that the true capacity of your tank is slightly greater than that stated in the technical sheet. But these differences are usually fairly insignificant, so maybe you shouldn’t count on it! In short, the best is to have an exhaustive control of what your bike consumes under different conditions and calculate so that you never run out of petrol, an event which can spoil a journey or turn a normal day…..into one of rage!!