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Fuel prices: how to save £500 a year (even if it does mean driving at 20mph)
Record prices at the pumps could succeed where 6,000 cameras and millions of pounds in road-saftey advertising have failed for decades – by securing compliance with the speed limit.
Driving more slowly will save drivers up to £500 a year in fuel costs, according to a study, which reveals that the most efficient speed is much lower than most people think.
With the average price of petrol at £1.17 a litre and diesel at £1.30 – 20 per cent higher than a year ago – the financial incentive to obey the speed limit has never been greater.
Car manufacturers suggest that the optimum speed for fuel efficiency is between 50mph and 60mph and a recent survey found that two thirds of drivers believe this to be the case. But the study, commissioned by What Car? magazine and based on five cars of different sizes ranging from a 1 litre Toyota Aygo to a 2.2 litre Land Rover Freelander, found that the most efficient speed was below 40mph for all five and as low as 20mph for two.
Above 40mph, fuel consumption increased sharply and by 90mph the miles per gallon had halved on average.
The study comes as the Government prepares to put in place emergency measures to prevent a strike by Shell oil tanker drivers from creating fuel shortages across the country. Downing Street urged drivers yesterday not to panic buy, which would cause shortages even if fuel deliveries continued as normal.
The study, by Peter De Nayer, a former AA fuel efficiency expert, involved fitting cars with a fuel flow meter and testing them at Millbrook proving ground in Bedfordshire. He found that a Citroën C4 1.6 diesel achieved 99.6mpg at 20mph but only 29.3mpg at 90mph.
The average car consumes 38 per cent more fuel at 70mph than it does over the same distance at 50mph. At 60mph it uses 34 per cent more than at 40mph.
The average driver travelling at 90mph on a motorway will spend £1.20 more on fuel every eight minutes than a driver travelling at 70mph. The 90mph driver will have travelled farther in that time but will still be spending 40 per cent more per mile than the 70mph driver.
The study also found that a driver of the average car travelling 10,000 motorway miles in a year at 80mph would spend £518 more on fuel than if he had driven the same distance at 60mph.
More than half of drivers on motorways break the 70mph limit and a fifth drive at more than 80mph, according to figures from the Department for Transport.
Mr De Nayer said: “There is a huge misconception that the most fuel-efficient speed is around 55mph. The study shows that the slower you go with the vehicle running smoothly, the less fuel you will use.
“By allowing a bit more time for their journeys, drivers will not only protect their licences from speeding points but save themselves a significant amount of money.”
Motorists are also wasting money by using the wrong gear. A car cruising at 40mph on rural roads uses 20 per cent more fuel in fourth gear compared with sixth, the study found. In town, motorists can cut fuel bills by pulling away slowly and smoothly, changing up early and anticipating road conditions to maintain a steady speed.
Mr De Nayer said that improvements by manufacturers to make cars quieter had fooled many drivers into thinking that their engines were running smoothly in lower gears. “They can no longer hear that they should change gear.”
Some manufacturers, including BMW and Audi, have begun installing gearshift indicators to help drivers to improve fuel efficiency.
Greater compliance with the speed limit would spare the environment as well as drivers’ wallets. The UK Energy Research Centre, a govern-ment-funded body, found that if all drivers observed the 70mph limit their vehicles would emit 3.7 million fewer tonnes of carbon dioxide a year. This would be the equivalent of taking three million Ford Focuses off the road.
The Society of Motor Manufacturers and Traders said: “It is unrealistic to expect people to drive much lower than the limit. You need to keep up with traffic and to maintain a safe and reasonable speed.”
If vehicle gearing was matched to national speed limits to enable optimal engine speeds and loads at the limits , improved fuel economy could be obtained. Unfortunately, many cars seem to be geared for maximum acceleration or high-speed autobahn cruising.
Ben Garside, Loughborough, UK
To those who advocate driving at 80 saves more time than the money driving at 60, it is unlikely you can average an ILLEGAL 80 unless your whole journey is on a clear motorway. Average speeds are misleading, the answer is to accellerate slowly, not put your foot down to get fast as soon as you can
Ron, Milton Keynes, UK
Alistair,
The engine is not always slowing the car (apart from it's weight) engine braking can only occur when in gear, as its the reluctance to turn over slowing the road wheels.
If all drivers took an interest in how there car worked it would help.
Rob, Gloucester,
In fact, why don't we reduce emissions by getting people who don't know how a car works off the road. A spacial awareness test would help too.
Rob, Gloucester,
Speed is not the most relevant factor in vehicle fuel efficiency, it is more related to engine revs (rpm) and engine loading.
A good driver can naturally feel when an engine is not running optimaly - and can confirm it with a digital mpg readout if their vehicle has an fuel management computer.
peterj, malvern, uk
I need a question clarified.
I need to travel 100 mile
If i travel at 80mph it takes me 75min to get there, if i travel at 60mph it takes me 100min.
Q. the fuel that i have saved going at 60mph rather than 80mph, will that not be lost because i still need to travel for a futher 25min
Steve Pateman, Sunbury on thames, UK
I am a biker (600cc Yamaha Fazer) and I can confirm that Land Rovers are the least efficient vehicles on the planet.
They shed so much turbulent air at 60MPH that they are very unpleasant to ride behind. Discoverys are the worst but Freelanders aren't much better. At 80MPH they are intolerable!
Pedro, Stratford,
I have tried downhill freewheeling & staying in gear and from the car's measurement of fuel consumption (both instant & average) freewheeling is farmore economical if you know when to disengage gear, and what exponents of staying in gear forget is that the engine is always slowing the car.
Alastair, Rye, UK
Why not just improve aerodynamics? Driving slow doesn't save nearly as much money as it wastes time. I think even worse though its hellishly boring, so no thanks, ill keep my current speed, and if push comes to shove ill distill my own fuel for cheaper then the pump can offer.
Nick Owczarzak, Belleville, Mi, USA
Dear Edward T, if you have a fairly modern car you're probably using _more_ fuel by freewheeling (aside from the legality arguments). Modern engine management systems often cut off the fuel if the car is moving in gear with no accelerator input. Even Clarkson now knows this ;-)
Minty, Bristol,
I believe that modern cars use no fuel at all when running downhill with no accelerator, so it is actually less fuel efficient to freewheel down hills.
John, Banbury,
The Millbrook proving ground is as flat as a pancake, in the real world the slightest incline would force you to change down a gear at these speeds, so it's all academic.
jon webb, cirencester,
I've been "eco driving" for the past couple of months now and manage to get an extra 100 miles out of my tank. It holds 40 litres of petrol and is a 8 year old 1.4ltr engine. What a difference!
Rich, Chippenham, Wilts
Recently I decided to drive at 70MPH on motorways to save fuel and it made quite a difference from the usual 85MPH it gave me another 15MPG on my deisel people carrier. I also tried 50MPH on motorways but It felt I was hardly moving and lifes too short for that although I was getting another 20MPG!
Nick, Sutton,
As a pensioner I don't really have to be anywhere at any particular time so I only put £480.00 of fuel in my car for the entire year. If the price fluctuates I still only buy £40.00 worth of fuel a month. Speed doesn't come into the equation. I always allow plenty of time for any journey.
Brian Faulkner, Bridgwater, UK
I can only talk about the south east but why do governement persist in not financing major mass transport systems ? Even Dubai is launching a Tram , we need major transport policy e.g London East West new line at £2 Billions, so what ? over 50 years and more ... fast train would help too.
mark, london ,
Edward T Green of Stevenage: Freewheeling in neutral is illegal as you do not have proper control of the vehicle (no engine braking for example)
Toadie, Salisbury, England
People travelling by whatever means is not good for the economy. Imagine a factory where all the parts were spending hours making needless journeys. If we all had to go for a year without car use I bet we would all swap jobs/homes and end up in a fairly similar situation. Think 1950s!
Clive Stringer, Eggesford, England
I test rode a Vectrix electric scooter yesterday. It goes well, and apparently costs 25 pence for a charge that's good for 60 miles. Now that's economy.
Simon Carswell, London, UK
Interesting article, the substance of which does not seem to register with many. - For the record my Rover 75 Diesel Tourer with the BMW engine returns 58mpg at a steady 50mph.
Eric, Malton, England
If I am on any down gradient I put the car in neutral and let gravity do the work. Your engine is ticking over at its lowest speed and burning the minimum amount of fuel. I might wear out my brake pads quicker, but the cost is more than off set by the saving in fuel. Freewheel when you can!
Edward T Green, Stevenage, UK
"Cut out all those frivolous journeys."
Only a Green extremist can possibly imagine that in the South-East of the UK, anyone is driving around for fun!
People HAVE to get to work, this generates enormous amounts of income tax revenue, without which the Social Security based UK would collapse.
James Dowling, London, UK
Interesting,my car a rover 75 does about 40.2 mpg at a steady 60 in top gear If i slow to 50 it drops to 37 speed up beyond 60 and the fuel consumption rapidly worsens .This is probably because top gear does not engage until 50 .My mini does indeed do better at 30 than 50. Guess which i use .
g p edlin, london,
Ever thought that it's better to arrive late, than dead-on-time?
Hehe.
And another great way to save fuel apart from cutting your speed is simply this: Don't drive so much. Cut out all those frivolous journeys. Learn to enjoy life-without-the-car.
David, Wellington, New Zealand
Not only would money be saved but also thousands of people's lives!
James McErlain, Tralee, Ireland
Why are so many people over concerned with saving time? What do they do with it when they saved all this time? Watch more TV? - Big deal! It isn't about saving time - it's about being impatient.
John, Llandeilo, Wales
Why don't they tackle the ever increasing amount of traffic lights and chicanes, these are wasting millions of tons of fuel
peter d, cardiff,
You can save very much more by going slower still, emitting no toxic gases in the air, improving your health and increasing your life span.
By biking.
San Ying, Montreal, Canada
Will & Ade. Your calculation is right, but it isn't the way that real journeys run. Check your average speed for a few journeys. Or set your on-board computer to display average speed. I think you will be surprised how little difference comes from doing the motorway sector 10 mph faster.
Brian Leeming, HUNTINGDON, UK
What is more precious than time? It's just as limited as fuel. Also the assumption is that some travel at 80mph all the time and some at lower speeds all of the time. Clearly on UK roads you cannot travel at any great speed for much of your journey becasue the road network is so bogged down. Rubbish
Mark Chisholm, Dereham, UK
The 'lost tax revenue' argument is specious, as any economics student will know. If we spent less on fuel (and therefore fuel tax), we would use the money more productively elsewhere, boosting the economy and generating greater CGT and sales and income taxes for the gov't. Everyone would win!
Johnny, London,
Drivers in London must be saving loads of money seeing as the average speed is 8mph! That said, on my 27 mile commute (1/2 on motorway) I average 36mph with only a 636cc engine and half the number of wheels to average road user! :-)
zio, London, UK
By the way - I still manage 46.8 mpg. :-)
zio, London, UK
Ive set my sat nav to "moo" at me if I exceed the speed limits. Outcome is:
1. I dont speed
2. Its saving me about 10% on fuel
3. It annoys the hell out of the wife
Andy, Peterborough,
To work only in 4 days of a week might be a sound solution in the US. (Does it mean no car in the rest of the week? Maybe.)
If 20 mph were acceptable, cheaper electricity sedan would be a good choice.
In China, large scale of public transportation is a popular way to meet all members' demand.
Zhuang Liyao, Tianjin, China
Finances have forced me to do this for some time. My 1.9l diesel people carrier will just about hold 35mph in 6th, so I mostly stick to gears 5 and 6. Round town a light touch on the accelerator reduces my fuel use from 35mpg to 50mpg. On the Motorway with 2 adults and 3 kids at 65mph = 60mpg!
Matt, London, UK
walk everywhere and you'll save even more money on petrol.
Quit your job and stay home eating cold beans, and you'll save even more too!
Arthur, Newcastle,
-"If we all drove at 20 mph, none of us would get done for speeding, how would the treasury cope with out all that money"
Easy! The govt would impose blanket 15mph speed limits.
Ted Bundrum, Darlaston,
I live in the Balearics, and when I arrived last September, diesel was €0.87 cents a litre. It is now €1.288. Random fact.
Before this current oil shock, for a while, many headlines were about global warming, and the need to reduce our reliance on fossil fuels.
Embrace the change!
jace, Santa Eulalia Del Rio,
£500 savings great! I can use that to pay the person holding the red flag whilst they walk in front of my vehicle. That should also please the anti car, anti speeding health and safety gang.
R Bain, derby,
I am certain people would drive slower to save fuel if they actually knew how quickly their fuel consumption dropped with increasing speed (air resistance being a function of the square of the speed). So it is not a surprise that the government has not made fuel metres mandatory in new cars.
Richard Temple, Sevenoaks, UK
That explains why all the people round our way drive so slow.
10mph in 30mph is quite normal.
I thought it was because they hadn't passed their tests.
andy, dagenham, england
One simple measure to allow drivers to understand the cost of fuel consumed on each drive is to provide fuel consumption data in MILES per LITRE rather than MILES per GALLON. Although the calc from Gal to L is reasonably straightforward, MPL instantly relates your consumption to your wallet!
john brooks, Northampton, Northamptonshire
Surely they didn't run the Citroen C4 in TOP gear at 20mph? If not, we should be told which gear was used. My Toyota diesel would not be happy at 40 mph in sixth gear, even if it uses less fuel at that speed. They should factor in the cost of early replacement of engine & transmission parts!
Paul, Taunton, Somerset
Hahahaha, can you imagine all the anger, not to mention the time lost in lost working hours if we all took to driving 20-40 mph on all roads, including motorways :)
Mags, Oxon, UK
Don't overlook the importance of maintaining tyre pressure.
My petrol consumption dropped to an average of 41mpg. I inflated the tyres and over the next 100 miles achieved 56mpg.
Cias, Plymouth,
So we all drive at 20 mph and productivity and competitiveness in the UK slips to the bottom of the international league tables.
MarkS, Leeds,
It's true. I own a Land Rover Discovery and a Range Rover. I accelerate gradually from stationary, drive around 40 to 45mph and cruise towards traffic lights, junctions etc. A 100% sales tax on brake parts would encourage less erratic driving. People drive far too fast and save very little time
Dr Stuart H Russell, Grantham, UK
Drive slowly on the days when you are not going to work. I found this really helpful in saving fuel and money. Plus its always good to drive around the speed limit even though there are no cameras.. Its better late than never especially if its cheaper and greener.
Ashwin Rao, Bristol, UK
All this is irrelevant if you're sat in a motorway traffic jam caused by poor off ramp organisation or one of the traffic officers making sure a hedgehog can cross the road safely.
Alistair Kipling, Birmingham,
Won't be long before the Dept against Transport leap on this as evidence that all speed limits need to be halved and the amount of speed cameras doubled.
Revenue ahoy! Mind you, no one will have a driving licence before long, we'll all be taxed or prosecuted off the roads.
Steve J, Derby, UK
Well, I don't believe this, at least not for the car I drive (Passat auto.) My most efficient speed is the lowest at which 5th gear will engage. There is no chance that will happen at 20mph. Even so, my overall mpg is 40-43 mpg.
Alan, Llanerchymedd, Wales
If we all drove at 20 mph, none of us would get done for speeding, how would the treasury cope with out all that money
zylon, northampton, northants
Duh ! Less fuel use means less tax revenues so they will just continue to increase it .....Why don't people focus on the real issue.... It's a finite resource and we need to get the most out of it ..........Price is one of the ways to force people to use it more wisely...
Nigel, kl,
look at us, we earn lots of money. considering this extra speed may earn you an extra 12 mins a day of not driving. so after about 5 days you have spent about £12.43 for those few minutes, which if you dont earn much is hardly worth it. although i doubt it will help my impatience having said that.
james, norwich,
If you use the 'time is money' argument and use it a basis for lifestyle changes you'd have a pretty odd life. In fact, you'd probably end up living at work. That would be fun. And you could have the added satisfaction of knowing that you were going to be the richest man in the graveyard.
Roddy Campbell, Christchurch, New Zealand
I wonder how much the nation would deprive the Treasury of revenue if we all halved our fuel compsumption by suddenly driving around at 20mph plus the tax from lost earnings as noted by Will & Ade?
Ed, Harrogate, England
Yes, Will and Ade but surely you have to factor in more "pit stops" as well to buy petrol if you are driving at a higher speed and increasing fuel consumption?
Carl, Paphos, Cyprus
I wonder how long it would take to make me a million quid if I were to drive in reverse gear??
Deepak, Wayland, USA
Wallasey and Pugsley need to apply tax (cost/reduction) to their calculations
Rich, Canterbury, UK
10,000 miles at 80mph takes 126hrs, 41.7 hours less than the same distance at 60mph.
i.e. An entire working week less time driving means an entire extra week of earnings, and at £1500/week , a net gain of nearly £1000.
Looks like I'll be carrying on at 80mph... :)
Ade, Wallasey, UK
In al these calculations you seem to forget the cost of your time, driving 10000 miles at 80mph takes 125hours, at 60mph 166.6hours. Difference 41 hours, £518/41hours=£12.43 per hour, if you value your time at more than £12.43 per hour then it makes economic sense to travel at 80mph.
will pugsley, cambridge, uk