Having scanned the relevant statute law and authorities, may I dispel the mistaken belief mentioned in your interesting article on freewheels (Motor Sport, May 1974) that freewheeling or “coasting” is some kind of illegal practice. There is no statutory prohibition on the use of a freewheel nor any legislation forbidding a driver, if he so chooses, from coasting out of gear. The Highway Code does not discourage it, nor do the Construction and Use Regulations curb the installation of freewheels in passenger vehicles, or you could be sure that manufacturers such as Saab and Rover would have discovered it. As the owner of a Saab 96 I have the manufacturer’s comprehensive handbook which both instructs and encourages owners in the use of this fuel-saving device. I imagine that the belief that coasting is not permissible arose in the days when brakes were less efficient than they are today and also because of that old maxim of good driving that says “Always be in the right gear at the right time”. I took that to encourage the use of engine-braking and the heel-and-toe technique and I well remember being disconcerted a decade ago to learn that a certain high-performance course discouraged the use of gears when, say, braking for a roundabout from three-figure speeds, on the basis that disc pads were cheaper to replace than gearboxes!
[It also applied, presumably, in the days of “crash” gearboxes when even an expert might experience difficulty in getting from neutral into a low gear if his vehicle began to get away while coasting down a hill.—ED.]
However, the Ministry of Transport Manual entitled “Driving”, published in 1969, has this to say:
“Any form of coasting is wrong, because it lessens the driver’s control of the car, and particularly of steering and braking.”
This assertion is based, the Foreword tells us, on the experience of 30 years of driver testing. I would respectfully agree with the authors to the extent that coasting should not be encouraged with inexperienced drivers or in cars with inadequate brakes. With that proviso, my own view is that, whilst undeniably one cannot call upon engine-braking in an emergency such as total brake failure, nevertheless any reasonably competent driver should feel insulted if it be suggested that he cannot make safe use of freewheeling in today’s cars. Saab actually advocate the use of the freewheel in treacherous conditions on the basis that wheels that are neither driven nor braked will be least likely to skid.
As I see it, the only way in which a driver could possibly be penalised for using the freewheel or coasting would be if his use of the car in this manner could be shown to amount to careless or dangerous driving. Having experience both of a freewheel and of the circumstances in which Courts tend to uphold charges of these kind, I find it difficult to envisage a case where sensible freewheeling could be the subject of any criticism. Certainly my own car, when freewheeling with the engine idling, it charging the battery via an alternator and providing sufficient vacuum for the servo brakes (which are, anyway, of the split-system fail-safe type). Provided one is aware of the altered running characteristics there need be no anxious moments with the freewheel operating. Indeed, if it were to be suggested that freewheels are dangerous, then the authorities would have to take a hard look at cableoperated, rubber block-braked pedal cycles!
As for fuel saving, I have my doubts about the claims made. It is true that if I go all out for economy I can, with the use of the freewheel, improve from my normal 30 m.p.g. to nearly 40 m.p.g. in open-road driving. But this requires such a repression of mY natural instincts and results in such depressing average speeds that, for practical purposes, the freewheel gains me only about 2 m.p.g. in normal driving which, in my case, saves me perhaps £18 per year. Is it really worth it?
Capel Llanilltern C. G. Masterman