Across the UK rising fuel costs are putting a huge strain on household finances. With energy costs, supermarket prices, and council tax increases already ramping up the pressure the latest sky-high increases to petrol and diesel have left many already struggling families wondering how they're going to meet their monthly bills.
Last week the average cost of a full tank of petrol for a typical 55-litre family car exceeded £100 for the first time, according to figures from data firm Experian Catalist. The average price of a litre of petrol at UK forecourts reached a record 182.3p on Wednesday and the average price of a litre of diesel on Wednesday was a record 188.1p.
Read more: How much petrol and diesel cost in other countries in Europe compare with the UK
But with so much conflicting advice flying around it can be difficult to separate fact from fiction when it comes to the best ways to save on your fuel costs. So we've put together some of the best advice from the likes of the RAC's online motoring magazine Energy Saving Trust, Confused.com, and more to give you the best chance possible of saving money on fuel. We've also highlighted some of the most often-cited myths and explained which to take note of and which to ignore.
Drive efficiently by gearing up
One of the most basic tips on driving efficiently, and something cited by almost any motoring expert, is to change gears as soon as you can rather than relying on your right foot constantly being on the accelerator. This is because, of all things, excessive speed is often cited as the biggest fuel-guzzling factor. Driving at high revs increases fuel consumption so when accelerating change up early, driving in the highest possible gear for your car while keeping within the speed limit.
This applies across driving – things like braking quickly, speeding up, and slowing down suddenly and heavy-handed use of the steering, as well as other features of driving style, are all likely to impact on fuel consumption. Ideally it's best to anticipate, drive smoothly, and rely on the gears to do the work as much as you can, only accelerating when needed.
Tyre pressure
One often overlooked way to save is by making sure your tyre pressure is correct. Under-inflated tyres increase your vehicle’s drag, which increases fuel consumption. A study by the National Highway Traffic Safety Administration (NHTSA) in the USA found that every 1% decrease in tyre pressure correlated to a 0.3% reduction in fuel economy. This means under-inflation of the tyre by 10% increases fuel consumption by 2%. At 20% under-inflation fuel consumption increases by 4%.
Looking at those numbers the impact of tyre pressure on your costs is clear so make sure your tyres are inflated to the correct pressure. This should be in your owner's manual, in the sill of the driver's door, or on the inside of the fuel tank flap.
Don't use your AC or heating unless you really need to
Yes, we know how tempting it is first thing on a cold winter morning to whack the heating up to the max on your commute to work. Likewise, how many times have you cranked up the AC while out driving on a summer's day?
But if you want to save fuel it might be worth avoiding this unless you really need to. Operating the heating in the car uses engine power and therefore increases fuel consumption. This goes for heat as well as cooling so, while it sounds stupid, it's best to dress appropriately if you are really trying to save on fuel.
Don't be weighed down by things you don't need
While they're handy for trips abroad keeping roof boxes and racks on top of your car creates wind resistance and causes your car to use more fuel through the ‘drag’ effect. This is increased the faster you drive. According to the Energy Saving Trust an empty roof rack adds 16% drag when driving at 75mph. At the same speed a roof box adds 39%, making your vehicle much less fuel efficient. It might sound funny but the same effect (albeit it a lot less) even happens with the little flags you attach to the side of your car.
Perhaps unsurprisingly this also applies to those of you who like to use your car boot as an informal storage space. While it's unlikely to make a massive difference to your fuel costs it stands to reason that filling up your car makes it heavier which will result in using slightly more fuel. So put those boxes lying in the boot into the attic if you can.
Combine journeys
How warm your engine is will also impact fuel consumption. A cold engine is likely to use more fuel versus when it has warmed up, even though the mileage travelled might be the same. So if you're planning out your day it might be worth considering how many things you can pack into a single trip rather than turning off and re-starting the car repeatedly. Doing this can help you save on fuel, although with school runs, commutes, shopping, and after-school activities this obviously won't always be possible.
Should you drive around with less fuel in your tank?
One solution often touted is that you should drive with less fuel as it means you carry less weight. This is a tricky one. On the one hand the advice of many experts – that a fully-filled tank is heavier to drive around and therefore will affect efficiency – seems to make sense given our earlier advice about weight. But others say that your gas tank, when full, accounts for less than 5% of your car's total weight. Reducing the weight of your car by 2.5% by only filling your tank half full is therefore unlikely to have a noticeable effect on your fuel consumption.
The advice here is that whether you half-fill your tank or fully fill it is unlikely to have a major impact on your consumption – if there is any it is likely to be pennies. This is particularly true when factoring in the additional trips to the petrol station that would be required by filling up by less.
Should I run my fuel tank right down before refilling?
This one seems to be a little clearer. Most experts agree you should avoid regularly running on empty, or close to empty, as it creates a number of risks. As well as the obvious risk of running out of fuel in the middle of the road driving with really low fuel levels could also damage your car.
As the fuel level gets lower the car starts picking up debris from the bottom of the tank which can damage both the fuel filter and the pump. The catalytic converter could also be damaged. If you run out of petrol it can cause the fuel pump to run dry, which could land you with a hefty garage bill. Generally speaking it is ideal not to let your gauge fall below a quarter of a tank, according to multiple experts.
How far you can go when the fuel gauge hits zero?
How much further you can drive after your fuel light goes on depends on your car. For example, according to Confused.com, you've normally got around 42 miles left in a Ford Focus but only 30 in an Audi TT.
Similarly once the fuel gauge hits zero how much further you can drive depends on the car. Generally speaking it's about another 10 to 20 miles but this is not certain and is best avoided if you don't want the car grinding to a halt in the middle of the road as well as potentially causing other issues. So the good news is you're not going to cut out the minute you hit zero – but it's best avoided anyway.
What is the optimum fuel-efficient speed to drive at?
This is another common myth. Generally speaking there is no one driving speed which is optimum for fuel economy. Over the years the speed of 56mph has often been talked about as being the optimum speed. As RAC explains this was due to the old fuel consumption test being run at three speeds: urban, 56mph, and 75mph – and 56mph was always the most efficient of these. Typically cars are most efficient at 45-50mph but there are many other factors such as those cited above that collectively impact on fuel efficiency so this is not really applicable on its own.
Should I fill up in the morning?
It is sometimes said that filling up your car in the morning or late at night will give you more fuel for your money as petrol or diesel will be denser when cold. While this is true in theory in most cases the fuel you get when you go to a station is stored in big underground tanks which keep the fuel temperature-controlled. This means the fuel you buy will be pretty much the same temperature throughout the day and night. Even the fuel coming straight off the fuel trucks, as we saw a few months ago when shortages hit the UK, is temperature-controlled. Gas becomes more volatile when it’s hot so big fuel trucks are also insulated. Therefore you shouldn't focus too much on filling up in the morning or evening – whenever you need fuel is the optimum time to do so.
Should I keep my tank half-full to avoid fuel evaporating?
Again this one is unlikely to make much difference. It is sometimes said that the more fuel you have in your tank the less air is occupying its empty space meaning there is less likelihood of your petrol evaporating. According to MotorBiscuit.com even in a nearly empty tank the ratio of liquid/vapour gasoline is stable and no gasoline really disappears. Studies have shown that even if it were true your money savings would be negligible.
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