The Great MPG Contest

Do the best small cars really use less fuel than a scooter? We pitted a Kia Rio (claims 88.3mpg) against a Honda Vision 110 to find outIMG_5096

You hear it all the time these days: “My car uses less fuel than your scooter.” Given the number of tiddly hatchbacks claiming over 70mpg – even over 80mpg – while a Silverwing or Burgman 650 uses more, it’s hard to argue against. And if it’s true, that’s bad news. We all know that two wheels are more fun than four, that they’re more efficient in traffic and take up less road space. But it’s hard to persuade a sceptical Government that they should be given a fair crack of the whip when they apparently drink more fuel than a car.

To find out the truth, we pitted the most frugal small diesel car on the market – the Kia Rio EcoDynamics – against a three-year-old Honda Vision 110. The car is Kia’s economy-special, with a 1.1-litre three-cylinder diesel, uber-high gearing and idle-stop (which switches the engine off at red lights). According to the official mpg figures, it hits 88.3mpg on the combined cycle and over 94mpg on extra-urban, which in theory puts it close to 125cc territory. In practice, these official figures have been widely discredited as having little relation to the real world, for several reasons. They are produced a rolling road, not out on the street, by the car manufacturers themselves, and at an ambient temperature of 20-30 degrees C. None of that has much relevance to the average stop-start commute on a cold day.

Fortunately, more real-world figures are available. What Car? magazine has devised its own standard on-road test, and every car they’ve tested has used more fuel than the official figures say it should. According to them, the Kia can manage 70.6mpg, though that still makes it the most economical four-seater car you can buy.

The most frugal two-wheeler you can buy (again, according to official mpg figures) is a tie between Honda’s Wave 110 (a direct descendant of the old step-through) and the geared CBF125, both boasting 158.2mpg. But we couldn’t get hold of either, so settled for the Vision instead, a bog standard scooter from our local Honda dealer, with twist & go transmission and a 108cc fuel-injected motor. Unlike Honda’s PCX 125, there’s no idle-stop or other fancy fuel saving gizmos. It claims an official 141.8mpg.

Big Variations

So what happened? In its first few days on test, the Kia simply drank fuel, managing only 50mpg on short, cold drives across town, though improving to 65-70mpg on longer commutes. But it did respond to driving technique, creeping over 80mpg on even longer, gentler drives – the trick was to change up early, and a little green light on the dash encourages you to change up at 2000rpm. The Vision fell well short of its official figure, giving a consistent 106-107mpg, though that was mostly on main roads at 50-60mph. Given the little scooter is almost flat-out at sixty, that was quite a tough test.

What we really needed to do was test both of them back to back at the same speeds. We already knew that neither car nor scooter would reach its official mpg figure in typical conditions, but what about if we rode/drove them with fuel economy in mind? To find out, we spent most of a day on a 50-mile trip around the Somerset Levels (the bits that weren’t underwater). There aren’t many hills in these parts, and it was a Sunday, so traffic was reasonably light. There were plenty of 30mph limits and we kept down to 40-50mph on the open road bits, using gentle acceleration in between the two.

At this pace, the Vision had no problem keeping up with the car, and if anything the positions were reversed on hills (there are a few on the Levels). The Kia driver tended to hang on to a high gear, to maximise economy, but the Vision’s CVT automatically changed down and we’d creep ahead. That’s why the Honda Wave delivers even better economy than the Vision. It’s based on older technology, but with a semi-manual gearchange (like the old Honda stepthrough) it’s possible to hang onto higher gears, giving lower revs and more mpg.

After admiring the inland sea that passed for this part of Somerset in February, we took a final measurement. Incidentally, the car’s mpg was measured using its own readout on the dash – we can’t vouch for its accuracy, but it’s unlikely to have been pessimistic. The Vision used the lower tech method of brimming the tank, zeroing the trip, then brimming again after the test. Obviously this depends on tripmeter accuracy, but it’s good enough to give an indication of what’s going on. Anyway, the end result of our economy run, not surprisingly, gave the best figures of the whole test – the Kia managed 85.5mpg, still a whisker short of the official figure, and the Vision 152mpg, which was better than the official figure. Maybe more representative of day to day driving were the overall figures for the entire test: Kia 76.9mpg, Vision 121.7mpg.


What did we prove? That even a fairly basic scooter still uses a lot less fuel than the most high-tech eco-minded car. Car advocates will argue that the Kia can carry four or five people in comfort, but how often do see cars used that efficiently, especially on commutes? Also, to get even close to the official mpg figures, you have to drive very slowly. Either way, a small scooter or motorcycle will always use less fuel than a small car.



Running Costs – Car vs Scooter

Here’s a thing. The car uses a lot more fuel than the scooter, but it’s cheaper to service, and pays no road tax. But it will still cost more to run, thanks to higher insurance premiums and the depreciation from that £13,000-plus price tag.

                            Honda Vision 110                                      Kia Rio Ecodynamics

Price                    £1899                                                        £13,795

Fuel*                    £261                                                          £450

Servicing**          £200                                                           £130

Road Tax             £17                                                            Zero

Insurance***        £350.06                                                     £696.77

TOTAL £828.06 £1276.77

*Assumes 5000 miles/year, £1.40/litre, What Car? Mpg test (car) and our average mpg for the Vision

** Rio annual service alternates between £60 and £200

***Quote fom Carole Nash – Comprehensive, 35-year-old, 5+ years NCB, Birmingham


MPG Chaos?

If car fuel consumption figures seem confusing, then those for bikes are worse. Until recently, there were no official figures at all, and we had to rely on wildly varying road test figures (journalists, eh?) or word of mouth. Incidentally, having no official figures has been one justification given by Government for not grading bike/scooter road tax according to CO2 output – that’s why 125s still pay road tax, while small cars that use more fuel and take up a lot more road space pay none at all.

However, this is in the process of changing. A new scooter/bike specific test cycle, the WMTC (World Motorcycle Test Cycle) is coming in – manufacturers can use it now, but they won’t be obliged to publish these figures until 2017. Still, even if WMTC is as flawed as the car standard, it should be an improvement, as it’s a basis for comparison of different bikes, though Piaggio, for one, doesn’t appear to think much of it (see box).

Either way, until 2017 we’re left with a bit of a dog’s breakfast. ‘Manufacturers are free to publish (if they wish) figures obtained from various different methods of measuring fuel consumption,’ says Tom Waterer, the MCIA’s Technical Consultant. ‘This could be at a steady speed, or the WMTC or ECE cycles, or any other reasonable source.’

So who does what? The big Japanese manufacturers have all decided to voluntarily quote WMTC figures, but even here the picture is patchy. Honda and Suzuki do quote WMTC figures for some of their bikes, but not all – it’s probable that some older models haven’t been tested to WMTC standards yet. Yamaha and Kawasaki don’t quote any figures at all.

Piaggio doesn’t either, because it’s not impressed by the WMTC method of extrapolating mpg figures from a bench test. As for the others, Triumph, BMW and Harley-Davidson all use different methods: Triumph favours the old car system of an urban cycle plus steady 56mph and 75mph; BMW offers those steady speed figures only; and Harley (of course) uses an American system. Take your pick!

Honda (WMTC figures)

  CBF 125 158.2mpg

  PCX 125 132.3mpg

  Vision 50 145.1mpg

  NC700 DCT 78.6mpg

  FireBlade 47.1mpg

Suzuki (WMTC figures)

  Inazuma 250 85.9mpg

  V-Strom 650 71.2mpg

  Burgman 650 60.5mpg

  GSXR-1000 54.8mpg

BMW (at constant 56/75mph)

  C600 Sport 64.1/50.3mpg

  F800GT 82.9/65.6mpg

  1200 GS 68.8/51.3mpg

Kymco (basis not stated)

  People One +100mpg

  Like 125 +100mpg

  Downtown 300 +60mpg


Why Should I be Bothered?

Not bothered about fuel consumption? For years, it’s been a low priority for many scooter riders and many more bikers, for understandable reasons. Small bikes and scooters, as we’ve shown, use less juice than the most economical car, so the cost of fuel isn’t such an issue for us. Also, although a lot of us commute every day, annual mileages tend to be lower than cars – some two-wheelers are used for leisure only, wheeled out on sunny weekends and covering only 2-3000 miles a year. For leisure riders, paying £10-£15 for an afternoon’s fun isn’t a big deal.

On the other hand, the world is changing. No T&G reader will need reminding that the price of petrol has gone up, and up…and up. Global demand for oil is rocketing (mainly in China and other developing nations) and with a finite supply that won’t last forever, that puts the price up. The era of cheap oil is over, and the future will almost certainly include the £2 litre.

Following on from that, the Government’s priority is to promote low-carbon eco-friendly forms of transport – hence the increasing emphasis on cycling. To be similarly favoured, bikes and scooters need to have better eco-credentials, something the WMTC figures should make clear. Fuel consumption matters, whether it affects our pockets or Government policy.

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