500 miles in the Toyota iQ

We’ve reluctantly returned our iQ to Toyota HQ, and had a chance to reflect on last week’s 500-mile drive.

We set out to prove that iQ is an efficient car, but also that it’s not only possible to match a car’s official fuel consumption figures – you can beat them in real driving on real roads.

iQ’s tank holds seven imperial gallons (32 litres) of fuel; after we filled it to the brim we managed to go for 504.2 miles. Allowing for some extra fuel in the filler pipe, we managed 70-72mpg – the car’s official figure is 65.7mpg.

We’re really happy with our result, but there’s no doubt we could have got further. We drove into the centre of 18 cities and met heavy traffic in several – notably Wolverhampton, Birmingham and Oxford. We had a couple of hours of heavy rain in Wales, and used headlights during six hours of our first day’s driving.

Of course, bad weather and darkness are unavoidable at this time of year (we’re glad we missed this week’s snow), and it’s fair to say that we made a couple of our own problems. Chief among these was our route, which – particularly on the first day’s driving across the West Country – took in many hilly, bendy and narrow back roads. We were surprised to discover just how much more fuel we used on these than on motorways, where we could keep up a more constant, faster speed.

It’s not just our route that would have benefited from a bit of extra research, either. Neither Mark or I had attempted this kind of economy challenge before, and while we sought advice from others who had attempted similar feats, we’ve discovered a wealth of extra resources since we returned – not least of which is the information provided by cleanmpg.com.

What we learned

What we did show is that it’s possible for any driver to save on fuel by changing their driving style. We discovered that doing so takes a bit of practice and a lot of concentration, but that it definitely isn’t dull. It isn’t unsafe, either – many of the most effective techniques rely on good observation and anticipation.

It may sound obvious, but cars use the most fuel when accelerating, so the key to saving it is to accelerate gently and avoid slowing down as much as possible. We learned a lot in our two-day drive – and are by no means experts now – but here are the techniques we found to be easy and effective:

• Don’t drive too quickly – recent tests by What Car? showed that the most economical speed is the slowest that you can drive in top gear without the engine labouring – in iQ’s case that’s about 35mph. But depending on the road, the minimum safe speed may be much higher – we maintained around 55-65mph on motorways.
• Leave a gap – leaving a large gap to the driver in front let us accommodate many of their actions without having to hit the brakes at all. It’s also much safer in an emergency.
• Cornering – throwing a car through corners can be dangerous, but slowing down too much wastes energy. We read the road ahead as much as possible and tried to keep our speed through corners, slowing when necessary by coming off the accelerator well in advance rather than braking. A good gap helps here, as many other drivers slow more than they need to.
• Coasting – on suitable downhill stretches we took the car out of gear and coasted. It’s vital to leave the engine running, though, as it provides braking and steering assistance. Never remove the keys from the ignition when moving.
• Drafting – A lorry or coach moves a huge amount of air, and we picked up the benefits of this by following behind them. Keep a safe distance, though – never get so close you can’t see what the traffic in front is doing, or react in time to an emergency.

You can read comprehensive tips from experienced hypermilers at cleanmpg.com. As we’re happy to admit, we’re novices at this, and we know that our results will be beaten soon.

If you do better, we’d love to hear about it.

Our attempt has attracted criticism in the cleanmpg forums, much of it around our use of ‘hypermiling‘: the term was coined by cleanmpg.com owner Wayne Gerdes. Strictly speaking, having beaten iQ’s combined fuel economy figures we qualify as hypermilers, but Wayne and some of the forum’s members feel that by using the term to describe only a modest improvement over the car’s official figures, we’ve attracted criticism to the concept of hypermiling itself – that certainly isn’t what we intended.


    1. I found this the first block on the fuel cage drops very quickly and then when it gets near the bottom it just disappears saying (r) not sure how many miles you get when this shows.

  1. I have just read the above report I have had my IQ 8 months I have not taken it on the motorway and I am having problems with the fuel consumption I fill it to the top the gauge seems to go down very quickly and the gauge flashes under 400 miles surely I should be getting more mpg

    Jacqueline Spilsbury

  2. Having drove to tobacco docks and back from mildenhall in suffolk I was driving about 70-75 on the m11 my average miles per gallon was 52 no were near the amount of to gallon that toyota say it does, a bit disappointed form 70 miles per gallon that toyota gave this car,saying that it is one of the best small cars I have driven comfortable very low on noise and steady, I would give this car 7 out of 10.

  3. Hi Mark
    Thanks for your post.
    Great to hear that you love your iQ but sorry to hear your concerns regarding the fuel consumption.
    Fuel consumption figures are derived from a standard EU test undertake by all vehicle manufacturers to act as a guide and a level playing field to help customers when looking at a new car. Because the test in is undertaken in a laboratory, it is widely accepted that the figures do not represent real world driving conditions. We have published some articles to explain more about this and the following Blog post with links may help. https://mag.toyota.co.uk/how-official-fuel-economy-figures-are-calculated#.VClxufldXTo
    Hope this helps with further information but please let us know if you have any further questions.

  4. Hi Mark
    Just to mention on this one you will have approximately 8 – 10 litres of fuel left when the last bar goes out (when the sensor level reaches this point) but we do recommend finding a fuel station as quickly as possible.
    Hope this helps.

    1. Hi, I am finding our 64 plate IQ auto 1.0 struggles to do half the mpg of your claims in traffic; it had 3 bars of fuel left after 145 miles only and took just over 20 litres to re-fill. Hence with 12 litres of fuel remaining and 3 bars showing, how can zero bars of fuel on the dash display possibly be 8-10 litres as claimed? Approximately 250 miles to the tank is our average commuting with traffic or approx 35mpg. Urban claim is 47.1mpg.

      1. Hi Leon,
        We are sorry that you are experiencing this.
        We would suggest you visit your nearest Toyota Centre to have this looked at.
        You can find your nearest Toyota Centre here: http://fal.cn/VIdF.

    1. Hello again,

      Just to let you know that I’ve managed to beat my own mileage with 519.5 miles from a full tank. I wasn’t even trying to go and beat my previous mileage of 511 but hey I’ve done it!

      I’ve attached an image of the dash mileage to show how many miles I’ve done and a link to my most up to date fuelly log.



      What do you think Toyota? I do wonder what I could do with a Prius 🙂

  5. Hello Michael,

    I’ve tried to reply several times and my reply isn’t showing up!

    Great news! I’ve managed to beat Toyota’s 504 miles by going 511 miles, I believe I could have gone further than that but I wasn’t going to trust my calculations on how many miles of fuel I had left in the tank!

    On the 15th June, I managed to get 66.4 UK MPG from a full tank (35 litres).

    My stats can be seen on my fuelly.com page: http://www.fuelly.com/car/toyota/iq2/2009/markdpittam/375309

    Hope this response gets posted..


  6. Hi Mark,
    Thanks for letting us know. That’s very impressive, as always we’d love it if you kept us updated! Keep going…

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