Volvo DRIVe Preview Comments

Quote: "As economical and environmentally friendly as this system may be, I'm not so sure that encouraging drivers to coast in gear is a good idea, after all one of the basic principles of driving is that you should always be either accelerating or braking, not coasting."

In the Netherlands it is officially encouraged in driving lessons to coast in gear to minimise fuel consumption (called "Het Nieuwe Rijden" - The New Way of Driving). Actually, in normal driving everbody does a bit of coasting in gear, just for very short moments, and especially in small turns.

"one of the basic principles of driving is that you should always be either accelerating or braking, not coasting"

Only if you own shares in BP or Shell. The key to economical driving is to accelerate and break as little as possible, accelerating burns petrol and breaking wastes your kinetic energy as heat. I'd also argue that it makes you a better driver as you are having to constantly think ahead and anticipate.

"one of the basic principles of driving is that you should always be either accelerating or braking, not coasting."

Yes I've seen drivers do this on the motorway - very annoying!

I think you're getting driving principles mixed up with motor-racing principles

Quote: "As economical and environmentally friendly as this system may be, I'm not so sure that encouraging drivers to coast in gear is a good idea, after all one of the basic principles of driving is that you should always be either accelerating or braking, not coasting."

Although being a driver of now nearly 20 years, I do know that this theory is outdated. In current UK basic and advanced tuition (car, not bike - the latter has not changed and still places for emphasis on driver control) you are encouraged to accelerate firmly to the desired speed, short shifting if required, and then hold at the current speed.

Looking ahead, it is encouraged to read the road and allow the engine to brake the vehicle as much as possible to improve economy. Each manufacturer is different, but most engines will cut off fuel supply to the engine without any throttle input within 1 to 3 seconds. After that, there is no consumption. Idling in neutral or clutch in will of course still consume fuel.

To a driver of quite a few years experience, it feels odd at first to adopt this approach. To see a junction 1/2 mile ahead, and just leave the throttle and glide up to it in gear. It goes against the basics we are used to, which is to drive right up to the junction until the point where it is safe to brake smoothly and then execute the turn. It feels like you're going too slow, and the driver behind you will almost certainly close up, even though the difference is just a few mph.

But the fuel saving is extremely high, especially when in urban traffic.

This may be changed if / when KERS becomes more commonplace in production vehicles, but until it does, coasting in gear is a huge environmental plus.

I apply this principle when in my car all the time. It makes a big difference. A big enough difference that I can of course spend these savings on hooning my motorbike around at every opportunity (which, I hasten to add, still gets a good 50 mpg - not bad for a 650 cc). Plus, it is fun ;)

107hp diesel in an S80/V70? I had a 2.5 petrol 850 estate (became the V70) hire car once, and that was no ball of fire. You'd probably have your foot to the floor the whole time with the 1.6 diesel.

I've found I get better economy out of a bigger engine you're not thrashing all the time.