ADUK Archive

We should always bear in mind that economy is not only based on gas mileage, but also on mechanical wear. Therefore, it's also economically important to run the car on high revs periodically.

Astraist wrote:it's also economically important to run the car on high revs periodically.

Why?

WS wrote:

Astraist wrote:it's also economically important to run the car on high revs periodically.

Why?

I would imagine that a car driven constantly at low revs would suffer from sluggish performance after a while.

I know that I'm going back about forty years, but when filling up with petrol one day, I was talking to the assistant who was one of the mechanics about the various star ratings of petrol in relation to various vehicles. The conversation came round to older drivers. The mechanic said that it was not uncommon for older customers to ask if their car needed a de-coke as it wasn't running too well. He said that they usualy gave the car to the apprentice telling them to take it for a run up the A31. When they came back the car was usually running better due to the fact that they had floored the accelerator and given it a good blow out.

My neighbour came in the other day complaining that his Citroen Berlingo HDI was not running well, and would not accelerate properly. He had phoned the local garage and they had told him to drive it hard to blow the turbo out. He did this and said it belched out clouds of black smoke and after that it was running normally. Sooted up turbo due to driving it too gently?

fungus wrote:

WS wrote:

Astraist wrote:it's also economically important to run the car on high revs periodically.

Why?

I would imagine that a car driven constantly at low revs would suffer from sluggish performance after a while.

I know that I'm going back about forty years, but when filling up with petrol one day, I was talking to the assistant who was one of the mechanics about the various star ratings of petrol in relation to various vehicles. The conversation came round to older drivers. The mechanic said that it was not uncommon for older customers to ask if their car needed a de-coke as it wasn't running too well. He said that they usualy gave the car to the apprentice telling them to take it for a run up the A31. When they came back the car was usually running better due to the fact that they had floored the accelerator and given it a good blow out.

My neighbour came in the other day complaining that his Citroen Berlingo HDI was not running well, and would not accelerate properly. He had phoned the local garage and they had told him to drive it hard to blow the turbo out. He did this and said it belched out clouds of black smoke and after that it was running normally. Sooted up turbo due to driving it too gently?

Traditionally known as the "Italian tuneup", worked back then and still does.
"Eco driving", ain't high gear for as long as possible.
Requires more thinking.

fungus wrote:My neighbour came in the other day complaining that his Citroen Berlingo HDI was not running well, and would not accelerate properly. He had phoned the local garage and they had told him to drive it hard to blow the turbo out. He did this and said it belched out clouds of black smoke and after that it was running normally. Sooted up turbo due to driving it too gently?

I don't believe it's "soot in the turbo", but modern diesels are required to have particulate filters to reduce emissions (http://en.wikipedia.org/wiki/Diesel_particulate_filter). Some types require them to reach a certain heat to clean themselves - if this isn't achieved often enough (ie by using more engine revs and the turbo to create a hotter exhaust) it can cause engine damage/engine management lights requiring the filter to be taken off/changed - see the section in the article above about "Regeneration".

A squirt of easy start into the air filter works wonders for clearing the crap

mefoster wrote:Full throttle, but only up to 2500 rpm? I'm not sure that's even possible.

Full throttle meaning maximum pressure on the accelerator pedal. But then you have to change gear when you get to 2000-2500 rpm, depending on the type of engine.

Of course it is not only that, but mainly being able to maintain constant speed in a possibly high gear for long periods of time. Which is possible if your observation and anticipation are good enough.

I've never driven more economically than when I drive to the system. I spend less time on the breaks (thanks to the anticipation and observation involved), I use block changes (many times seen me accelerate off a roundabout in second from about 15-10 mph to 40 mph and then selecting fourth without bothering with third and the like), I almost never coast and actually I drive a lot quicker, smoother and safer this way too. What more can you want? =P

(worth mentioning I also only drive a 1ltr corsa... which might have a lot to do with it =P)

Paul_Black wrote:What more can you want? =P

More economy?

It's important to run the car periodically in high revs in order to clear out soot and improve lubrication. The car's data sheet usually specifies a certain period of time in which the car needs to be driven in high revs once a given period of time.

Back on topic for a moment:

foxtrot_mike wrote:But what about hesitation and progress at junctions, I like to take a few extra minutes to look and look again before pulling out checking for solos whether and vehicles overtaking.

Im also not very good at judging speed of other vehicles which doesnt help and need a few extra minutes to think.

I really hope you mean a couple of moments - wait for a couple of minutes at a junction and passers-by will start checking you for signs of life.

The systematic approach encouraged by Advanced Driving should help you here. On the approach to a junction or roundabout you can ascertain the geography and layout, and anticipate where hazards will be coming from. As you get closer and the view opens up you'll have slowed enough to check for those hazards, and if they (or any others) aren't there, then you're off without even stopping.

Drivers that only look to see if it's safe to go when they've already arrived at a hazard are not observing, anticipating or planning enough.

I've been in a few cars with drivers who aren't planning, and when they take a long time to make decisions at junctions they are punished for it by other road users. They get overtaken, cut up, pulled out on, beeped at or generally abused - it turns out that what they see as being extra cautious is actually creating problems.

I'd hope that your AD course will demonstrate that the best way to negotiate a roundabout or junction is to think about it before you get there, and help you to do it consistently.

MrToad wrote:...I've been in a few cars with drivers who aren't planning, and when they take a long time to make decisions at junctions they are punished for it by other road users. They get overtaken, cut up, pulled out on, beeped at or generally abused - it turns out that what they see as being extra cautious is actually creating problems...

I find that these problems are more often related to how clear the road needs to be before entering it rather than missing opportunities through poor planning. When traffic is heavy especially when it is moving at speed or it is difficult to judge that speed (bends and traffic moving uphill or downhill seem to affect this) then some drivers will rarely get an opportunity to make progress.

In these circumstances I find myself having to encroach a little on others' convenience whilst trying not compromise safety.