Cheap Petrol & Diesel

Cut prices & improve fuel efficiency

Some supermarkets are finally cutting petrol prices, but RAC figures show drivers are still facing some of the highest fuel prices we've seen in over four years, with the average price of petrol parked at 129.8p/litre. Yet it's possible to drive down costs if you buy in the right place, in the right way.

Of course, the trite solution is simply to use your car less, walk more or take public transport – and all that benefits the environment too. Yet even if you need to do the same mileage, you can slash costs with speedy, pain-free tricks to improve your car's fuel efficiency.

In this guide

MSE Challenge: The petrol diet!

Once you've read the steps below, why not try the petrol diet? No, we don't advocate swigging the stuff – it's a challenge on the MSE Forum, where MoneySavers share tips to help cut their annual fuel spend, track savings, and inspire others.

The forum's proved hugely powerful in the past, seeing people work together to get debt-free, pay off mortgages and more. It's free to join, and open to all – see the Petrol/Diesel Diet discussion.

Step 1: Make your car more fuel-efficient

We first compiled these tips a few years ago, with input from the RAC and AA – but the general principles still apply.

  1. Keep your tyres inflated

    Fuel efficiency improvement: Up to 3%

    Lower tyre pressure increases the drag on a car, meaning you need more fuel, so regularly check the pressures are correct and your car needs less oomph to keep it moving.

  2. Declutter your car

    Fuel efficiency improvement: Up to 2%

    The lighter your car is, the less effort it needs to accelerate. By decluttering, clearing out junk from the boot, and not carrying unnecessary weight, you can save more. On average, every extra 50kg you ride around with ups your petrol by 2% – and this could be even more in smaller cars.

  3. Take your roof rack off

    Fuel efficiency improvement: Up to 10%

    A roof rack, even unused, adds wind resistance to a car, increasing drag and making the engine work harder. The RAC estimates a roof rack can affect fuel consumption by a whopping 10%. If you don't need it, take it off, along with anything else inefficient. Even closing the windows will make the car run slightly more efficiently.

  4. Turn off air-con at lower speeds

    Fuel efficiency improvement: Up to 10%

    Newer cars are getting better on this, but air-conditioning still uses an incredible amount of fuel – so make sure it's turned off unless you really need it.

    The general consensus is it's more efficient to drive with the windows down and the air-con off at lower speeds, but at higher speeds it's better to use the air-con and keep windows up due to the extra drag caused by having windows down. At motorway speeds air-con can affect fuel consumption by about 3 to 4%, whereas it can be up to 10% in stop and start traffic.

    If you're not using your air-con, it's worth turning it on once in a while as not using it can mean it stops working. Also, don't keep the engine running. Drive off as soon as you start up and switch off the engine as soon as you reach your destination. Turn your engine off where possible, eg, in traffic or during big delays on motorways.

  5. Don't fill it up

    Fuel efficiency improvement: Up to 1%

    Fuel is heavy, so by filling the car up you're adding quite a weight. The less fuel your car has in it, the more efficiently it drives. If you fill up slightly more often and put less in (to 1/2 or 3/4 full), it'll make the car run more efficiently.

    But don't be tempted to run the fuel too low – winter driving uses more fuel, so you'll cover fewer miles per litre.

Step 2: Seven tips to drive more efficiently

You can drive the same distance in the same car, without slowing down, but using far less fuel. This is the biggest single factor effecting your fuel costs, and in some cases people find they save 30% when they change driving habits. The key is to drive smoothly. Here are the seven tips you need to know.

1. The accelerator is a money pump – accelerate gradually without over-revving.  Speed up smoothly. If you press harder on the pedal, more fuel will flow – but you can reach the same speed using much less power. As a rough rule, stay under 3,000 revs. Plus, if you think about it, if you accelerate too quickly, chances are you'll then have to brake hard, which isn't exactly efficient.

2. Change up a gear sooner. Always drive in the highest gear possible without labouring the engine. So change up much earlier than feels natural – it will take some pace out of your acceleration, but as that's our first tip it isn't a bad thing. If you have a fuel efficiency display, you'll be surprised how immediate an impact this has.

3. Think about road position. All the other tips require you to be alert and aware of your road position. This helps you plan ahead and move gradually. It also means that more efficient driving is also safer driving.

4. The brake is a money burner. Where safe, allow yourself to slow naturally rather than hitting the brakes. When you press the brake you are effectively converting the energy you've paid to put into the car into heat. Instead, where you can, make the most of the car's momentum - good road positioning is crucial for this. Over the course of a journey if you brake frequently, you'll find you end up having to accelerate more too, which ultimately means using more fuel. 

5. Listen to the noise of your engine. If you hear sharp acceleration and the screech of the brakes you know you're doing it wrong. Imagine driving from traffic light to traffic light doing that. The person behind who speeds up and slows down more slowly will still be behind you at the next light, they'll just have spent far less getting there.

6. Keep moving if you can. The most expensive metre you drive is always the first one when you start. It takes huge energy to get a car going. So if you can roll gradually up to a traffic light as it changes from red to green, without stopping, it is more efficient than stopping and restarting. 

7. Coasting in neutral may feel cheaper but it's dangerous. While putting the car into neutral and coasting may feel like you're using less fuel, it's dangerous, don't do it. You always need access to the accelerator to avoid unexpected hazards. Plus cars can handle far worse on sharp corners when in neutral.

In many ways, this all comes down to one little rule of thumb.

Every time you put your foot on the accelerator, remember the harder you press, the more fuel you spend.

Just being conscious of this, and your road position, should massively increase how far you can drive on a tank of petrol. It's estimated someone who averages 35 miles per gallon could reach 40mpg by driving better, a near-15% saving.

The real world impact: Martin's story

On an overseas holiday I got to test this, thanks to a sexy little digital display in my hire car which gave me a km/litre readout. For every trip, I drove normally on the way there and used the 'think when pressing the pedal' method above on the way back.

If you're thinking 'did he really bother while on holiday?' – yes I did, and I loved it. Luckily my girlfriend (now my wife) is very understanding!

The improvement is enormous!

Overall, I drove about 500 miles, and the different 'efficiency' averages per litre of petrol were incredible: for normal driving, it was 11.2 km per litre, but for efficiency-conscious driving, a remarkable 13.4 km per litre.

Most intriguingly, the efficient driving didn't cost me any time at all, and on motorways my top speed didn't change. Others drove harder, only to brake harder at the next traffic light...

- Martin Lewis, MSE founder & chair

For someone spending roughly £50 a week on fuel, an equivalent 20% efficiency increase would save around £500 a year. And, according to the RAC, boy racers could expect annual efficient driving gains of up to 30%.

For more info on this read Martin's Petrol Efficiency Experiment blog. If you try this type of driving or want to share your experiences, go to the Driving Efficiently forum discussion.

Step 3: Find the cheapest petrol or diesel prices

The easiest way to find the cheapest forecourt in your area for petrol, diesel, LPG (liquefied petroleum gas, used for heating and cooking as well as vehicles) and more is by comparing prices using a nifty free tool.

Go to website and after registering, enter your postcode and tell it how far you're willing to travel (five, 10 or 25 miles). It'll list that day's cheapest petrol stations in your area (it says prices are updated every weekday around noon, though we've seen the odd result that's a few days old) and covers most of the 8,500-ish forecourts across the UK. allows you to do 100 free searches a month, which should be enough unless you're doing some serious mileage. But an alternative if you need more is a similar tool – it covers slightly fewer petrol stations and is only updated once a week, but you can get up to 20 searches a week with a free account.

A quick check before you need to fill up could save you some decent cash. For a Manchester postcode, the price of unleaded within a five-mile radius on 15 October ranged from 121.9p/L to a pricey 136.9p/L. And while the difference per litre may be pennies, in percentage terms that's a gap of almost 12% between lowest and highest.

How does the cost of fuel break down?

Tax makes up a hefty portion a litre's cost. The current fuel duty rate for petrol and diesel is set at 57.95p/L, and you pay 21.6p/L VAT on petrol, and 22.8p/L on diesel.

Use loyalty schemes

Buying petrol is a regular outlay, and you spend more on it in a year than you think – £30 a week is over £1,500 a year. As many petrol stations (including the supermarket ones) run some form of loyalty scheme, it's worth signing up to schemes for the forecourts you'll use most regularly to get a little bit extra back.

However, never choose a petrol station just for its loyalty scheme, as the difference is small compared to petrol price variance (also see the Loyalty Points Boosting guide)

Other filling-up tips

There are several other ways to cut the cost of petrol and diesel:

  1. Always fill up at least 50 miles before your tank's dry

    Then there's no panic and you've enough time to get to a cheaper petrol station. Leave it longer and you'll fill up at the next one you see, so you won't be focused on price.

    This is slightly offset by the fact that a lighter car uses less fuel. But with 50 miles of fuel left, the difference is tiny.

  2. Only use 'better fuel' if your car can cope

    Many petrol stations sell 'high performance' fuels, yet there's little or no performance difference for most non-performance cars. So only fill up with the super-fuels if you've a sports car or you've been specifically advised your car will actually use the petrol correctly.

    The AA tells us that for most other cars, high performance fuels are too pricey for regular use. But if you're keen, it suggests using a high performance fuel every third or fourth tank full to keep the engine clean and efficient, then revert to normal fuel.

  3. Fill up at night?

    Talk of filling up at night getting you more is a slight urban myth, as the differences are minuscule – pennies at best. Petrol pumps are calibrated by volume, so fill up at night when it's cold and you get a tiny, tiny extra bit.

  4. Don't try to put more in after the clunk

    Filling up your tank to the top isn't great as it adds weight to the car (see how to make your car more fuel-efficient). But if you must, don't keep going after the petrol nozzle 'clunks'. If you do, you're overfilling.

Step 4: Pay using a cashback credit card

Cashback credit cards pay you back each time you spend on the card.

They are a great way to shave down the cost of fuel, but ALWAYS abide by...

Set up a direct debit to repay the card in full each month, so you never pay interest, which would outstrip any gain.

The reason card companies offer cashback or reward schemes is simple. They want to encourage you to spend on the card and pay them interest. The interest cost of all cashback cards dwarves the cashback you'll earn. For full details on things to consider before applying, see Cashback Credit Cards.

Each time you apply for one of these cards, you'll be credit-checked by the lenders. Multiple applications in a short period can impact your future ability to get credit. Read full details in the Credit Scores guide.

The easy way to pay off in full

It's easy to do this via direct debit, which allows the card company to take a variable monthly amount that corresponds with what you owe it. Sadly, some providers deliberately omit the 'pay off in full' option from direct debit forms, as it makes them less money. If that's the case, write 'pay off in full' on the form. They should honour it, but call up after a week or so to check they have.

The top cashback card

Here's our top pick currently, but also see other options in the Cashback Credit Cards guide.

Good for all-round spending: 5% intro cashback + up to 1% after

The American Express Platinum Cashback Everyday* is not specifically a petrol cashback card but as all spending's included, it's worth checking out if you fill up often. You get a massive 5% introductory cashback, then it's tiered up to 1%.

Need to knows
  • You earn 5% for first three months (max £2,000 spend, so £100 back), then 0.5% cashback on up to £5,000/year & 1% above this.
  • You must spend at least £3,000 on the card in a year or you will get NO cashback.
  • Make sure you repay IN FULL each month, or you'll pay interest at 22.9%.
Cashback: 3mths 5% (max £100), up to 1% after
Max cashback/year: N/A
Paid out: Month after card anniversary date
Annual fee: None
Min income: N/A
Min spend: £3,000
Card issuer: Amex
Rate: 22.9% representative APR (see the Official APR Example)

See how likely it is you'll get this card

MSE's Eligibility Calculator

Go straight to the lender


Step 5: Share the driving to cut your petrol costs

An easy way to cut petrol costs is to drive less! One option is to share lifts to work with friends. There are a few sites that connect people doing the same journey.

  • Liftshare

Register your details on Liftshare and enter the journey you'd like to share. Then check its search results for matching commuters, it also lets you search for potential matches before registering.

The site's been going since 1998. It reckons a typical daily commuter sharing a journey can save around £1,000/year. You'll also find a nifty savings calculator to help work out how much your journey costs, plus how much you could save by sharing with others.

  • BlaBlaCar

    Founded in France in 2006, BlaBlaCar came to the UK in 2011 and has 60 million members. It lets you search for potential matches without registering, but you'll need to register for free via Facebook or email if you want to contact a driver or offer a lift.

Anything to watch for?

  • Be safe

    The sites store details securely, but when it comes to travelling it's important to be vigilant. Arrange to meet for the first time in a public place, let friends or relatives know what you're doing and check their ID to ensure they are who they say they are.

  • Taking passengers shouldn't affect insurance

    If you're giving a lift to someone and asking for a contribution towards petrol costs, the Association of British Insurers says that provided there's no element of profit, your car insurance is unlikely to be affected.

    However, to be completely sure, check with your provider first.

Your successes using the five-step cheap petrol system

Do it – you'll be surprised'

Thanks to driving tips from @MoneySavingExp, I have saved myself £20 in fuel in 1 month, driving more carefully. Do it, you'll be surprised.
- MoneySaver @mathewhasker on Twitter

'I doubled my fuel economy!'

Over the last 2 years I have almost doubled my fuel economy, without changing vehicles.

1. I drive much more smoothly and don't overtake other car users just to get one or two places further along in a big queue.

2. I leave for work a little later and return home a little later – as a result I no longer spend 30 mins plus on a 4 mile crawl through stop/start traffic on a 26 mile (each way) commute into and out of Aberdeen.

My blood pressure is also lower
MoneySaver Caleypine

'20 extra miles per tank!'

Results I've got from trying to drive more fuel-efficiently. Most of this has been city driving:

Previously, 33-35 litres gave me around 215 miles.

Driving more carefully increased this to around 235 miles.

Turning engine off at lights increased my mileage to 293 miles.
- MoneySaver Krishna

How much can you save?

The savings from following the five-step system can be huge. For someone who drives 15,000 miles a year averaging 35 miles per gallon (12.4 km/L), just buying petrol at the average UK price would cost £2,527 annually as of November 2018. Cutting this spend by 25% could save £632/year.

To work out the initial approximate cost of running your car, the website has a fuel consumption search tool (it's best for new cars) which will help you work out roughly how much it'll cost you to run your car. Motoring website Honest John also has a handy 'real MPG' section where drivers have reported the miles per gallon they actually get.

Fuel cost-cutting

5,000 miles £842 £800 £674 £632 £210
15,000 miles £2,527 £2,401 £2,022 £1,895 £632
30,000 miles £5,054 £4,801 £4,043 £3,791 £1,263

(1) Cost at 35 miles per gallon (12.4 km/L) at 129.8p/L. Last updated November 2018.