Quote from P5YcHoM4N :

Mine told me the opposite. When a stop becomes a wait, take the car out of gear and pop on the hand brake. Although that is a personal thing, he didn't mind if I didn't bother with the gears as long as I did put on the hand brake.

To be honest neither way is wrong IMO, but the 'acceptable' driving standards for the test keep changing.

Quote from tristancliffe :

More revs and less throttle will be more efficient (and hence give more MPG - ignore what they are saying above).

Theoretically this shouldn’t be the way for an engine to work efficiently. (I understand you might know all these but this post is not just an answer to you)

More revs and less throttle increase energy consumption cause of pump loses. Internal combustion engines basically work like air pumps. Keeping the intake restricted while revs build up just increases the energy that pump needs in order to turn.

Ideally you’d want to run an engine with no "butterfly" resisting air flow at the intake, adjusting fuel mixture in order to modulate power output.
But this is not always possible because lean mixtures (a little fuel - a lot of air) tend to either not combust at all or combust too violently in a way that no engine can handle it.
The "violence" of air-fuel combustion depends on many aspects but mainly in temperature, pressure and mixture distribution existing in the combustion chamber.

Fuel management systems take account all these aspects and provide the proper air fuel ratio. Lean enough fuel mixtures for cruising speeds in mid rpm in part throttle operation, and rich enough mixtures for safely produced maximum power-torque in the whole rpm range at full throttle.
Because the engine works like a pump, by restricting air supply intake, vacuum increases and so combustion chamber pressure decreases.
The less combustion chamber pressure - the less prone fuel mixture is to combust "violently". But also the more like to not combust at all
(So nothing is a straight line here like “the more the better” or “the less the better”…)
Fuel management system is programmed to go as lean as possible in part throttle operation and that justifies the lower fuel consumption while keeping the intake restricted even in an inefficient way like the butterfly valve.


Id say keep the lower rpm that allow you to accelerate lively by not using more than 50% throttle.
Same goes with cruising. Keep the lower possible rpm that allow you to use low throttle (arround 20%) in order to maintain your speed.
But really this depends on your car's fuel management mapping and the air induction technology it uses.

Speaking about less that 1000rpm difference between gears:
Definitely the gear that allows you to travel with noticeably less throttle will let your fuel management system use less fuel.
If the difference in throttle position is not noticeable I’d say stick with lower rpm.

Quote from dougie-lampkin :

It takes a whole second to put in the clutch and engage a gear anyway, so I don't see what the safety issue is?

1 Second at 30mph = 45 Feet (approx 3 car lengths).

Tell me the inability to accelerate for 45 feet isn't a safety issue.

Take the scenario of someone pulling out of a blind side road looking in the opposite direction, with oncoming traffic in the other lane. Travelling down hill, they don't have to be that close before they're too close to be able to stop in time. The only option that leaves you with is accelerating your way out of trouble by getting past them before they get in front, (or into the side), of you. Suddenly that 45 feet, might very well be the difference between getting past them and not.

Only someone with out much experience driving would ever think that the inability to steer/brake/accelerate instantaneously doesn't constitute a lack of control of a vehicle.

For me it's simple, the brakes are there to slow you down, they are not there to maintain a speed- unless absolutely necessary- that's what the pedal on the right is there for. Coasting at anything other than a crawl is needless and quite idiotic imo.

Quote from sinbad :

For me it's simple, the brakes are there to slow you down, they are not there to maintain a speed- unless absolutely necessary- that's what the pedal on the right is there for. Coasting at anything other than a crawl is needless and quite idiotic imo.

You do realize that costing with the car in gear (assuming fuel injection) and clutch engaged cuts the fuel injectors, thus reducing fuel consumption. You weren't really clear about what you mean by coasting, so sorry if I misinterpreted it.

Quote from kaynd :

Theoretically this shouldn’t be the way for an engine to work efficiently. (I understand you might know all these but this post is not just an answer to you)

More revs and less throttle increase energy consumption cause of pump loses. Internal combustion engines basically work like air pumps. Keeping the intake restricted while revs build up just increases the energy that pump needs in order to turn.

Ideally you’d want to run an engine with no "butterfly" resisting air flow at the intake, adjusting fuel mixture in order to modulate power output.
But this is not always possible because lean mixtures (a little fuel - a lot of air) tend to either not combust at all or combust too violently in a way that no engine can handle it.
The "violence" of air-fuel combustion depends on many aspects but mainly in temperature, pressure and mixture distribution existing in the combustion chamber.

Fuel management systems take account all these aspects and provide the proper air fuel ratio. Lean enough fuel mixtures for cruising speeds in mid rpm in part throttle operation, and rich enough mixtures for safely produced maximum power-torque in the whole rpm range at full throttle.
Because the engine works like a pump, by restricting air supply intake, vacuum increases and so combustion chamber pressure decreases.
The less combustion chamber pressure - the less prone fuel mixture is to combust "violently". But also the more like to not combust at all
(So nothing is a straight line here like “the more the better” or “the less the better”…)
Fuel management system is programmed to go as lean as possible in part throttle operation and that justifies the lower fuel consumption while keeping the intake restricted even in an inefficient way like the butterfly valve.


Id say keep the lower rpm that allow you to accelerate lively by not using more than 50% throttle.
Same goes with cruising. Keep the lower possible rpm that allow you to use low throttle (arround 20%) in order to maintain your speed.
But really this depends on your car's fuel management mapping and the air induction technology it uses.

Speaking about less that 1000rpm difference between gears:
Definitely the gear that allows you to travel with noticeably less throttle will let your fuel management system use less fuel.
If the difference in throttle position is not noticeable I’d say stick with lower rpm.

Agreed, but 1500rpm and 100% throttle all the way up the hill, with the engine straining to stay in the engine mountings will be less efficient than 3000rpm and 50% throttle. Whilst I agree that more throttle will be more efficient than part throttle most of the time, it isn't when the full throttle test is way out of the engines working range.

Quote from speed1 :

You do realize that costing with the car in gear (assuming fuel injection) and clutch engaged cuts the fuel injectors, thus reducing fuel consumption. You weren't really clear about what you mean by coasting, so sorry if I misinterpreted it.

I don't consider that to be coasting if drive is still engaged. Obviously it's part of driving to lift the throttle and gently slow without applying the brake, but taking it out of gear, or declutching for an extended period at 60mph is different.

Quote from tristancliffe :

Agreed, but 1500rpm and 100% throttle all the way up the hill, with the engine straining to stay in the engine mountings will be less efficient than 3000rpm and 50% throttle. Whilst I agree that more throttle will be more efficient than part throttle most of the time, it isn't when the full throttle test is way out of the engines working range.

Yes that’s why I clearly state in my previous post that {nothing is a straight line here like “the more the better” or “the less the better” }.
Going full throttle at low rpm is comparable inefficient to going with too low throttle at high rpm. (By “throttle” I mean the pedal control of the car. Recent advanced engine management systems try to hold the electronically controlled butterfly valve as open as possible, trying to alter engine load by fuel mixture, ignition timing and valve lift-timing)

Well, staying near the RPM where the engine produces the maximal torque is probably the best way to go. This will allow you to accelerate at a good rate without straining the engine, with minimal throttle.
Keeping the right speed is important too..
http://en.wikipedia.org/wiki/F ... economy_vs_speed_1997.png

Quote from speed1 :

Plus, what happens if that truck behind you cant stop in time. You probably arent going to be able to get it in gear fast enough to avoid being rear ended.

Then he's an idiot who needs his licence revoked - granted that might not interest you anymore then, but still... If you rear-end someone, it is ALWAYS and WITHOUT EXCEPTION your fault! I would stop driving if I'd have to be always on the lookout for cars behind me to avoid an accident...

Not always and without exception. It's perfectly possible to be at fault in the leading car, it's just rarer.

There is also the mechanical failure issue. Not "ALWAYS and WITHOUT EXCEPTION" the fault of the driver. Sometimes things just happen.

Before it is said, and I know it will be, do you 100% inspect every single part of your car before you drive every single time?

mrodgers - i think he means legally, which is correct, the driver following is at fault.

Quote from tristancliffe :

Not always and without exception. It's perfectly possible to be at fault in the leading car, it's just rarer.

If you rear-end someone, you didn't leave enough space and/or went too fast. There is no possible way you can make an exception to that.

Quote from bbman :

Then he's an idiot who needs his licence revoked - granted that might not interest you anymore then, but still... If you rear-end someone, it is ALWAYS and WITHOUT EXCEPTION your fault! I would stop driving if I'd have to be always on the lookout for cars behind me to avoid an accident...

Tosh. That's rubbish, sorry. It's a rule that was made up by Insurance companies to make their job easy, not because it has any genuine merit.

The "theory" being if you are driving slow enough, with enough space and being attentive you should never hit the person in front. But the reality isn't like that. Driving on the road is only possible if people behave in predictable ways. If someone emergency stops in front of you for no reason you're going to tail end them. End of story. Why? because its IMPOSSIBLE to have a large enough gap between you and the vehicle in front in the real world. Why? because someone will pull in front of you and fill it. So what are drivers expected to do? keep backing off and end up going backwards?

Sorry but in the real world, a more pragmatic approach is called for. Over simplistic "rules" that don't fit with reality only suit certain parties, and have no basis in truth with regard to finding fault.

Quote from bbman :

If you rear-end someone, you didn't leave enough space and/or went too fast. There is no possible way you can make an exception to that.

Come and try driving in London for a day and see how far you get with your simplistic idealistic point of view.

I tend to agree with gezmoor ^^

EDIT: sigh, the one time I put "^^" and it's the first post on a new page. Figures...

most people aren't borgs, thus are using all their attention to look forward, not backward. i mean they don't have eyes on the back of their neck. because they aren't borgs... and borgs have eyes on the back of their neck... because they have machines and they... :/

when i drive, i need 101% attention towards the direction i am driving, because the moment i start paying attention towards where i am NOT driving means that there is an open possibility for something to **** up.

and then the excuse "i just looked for a split second in my rear mirror, honest! i'm a careful driver" somehow i think won't fly.

Quote from bbman :

I would stop driving if I'd have to be always on the lookout for cars behind me to avoid an accident...

Actually, thats by definition defensive driving, or paying attention to traffic around you. Anytime I hit the brakes, I subconsciously glance in my rear view mirror to see what traffic behind me is doing. Judging from that statement you made, I'm sure (whether of not you admit it), you just go when the light turns green. Admittedly, I often do as well, but I've avoided being hit by a light runner at least twice now by looking left and right. You've got to remember, I live in America, the home of some of the worst imaginable drivers. You've got to watch for dumbasses texting, dumbasses reaching for something on the floor, dumbasses doing makeup, dumbasses that are drunk, and so on.

Quote from bbman :

If you rear-end someone, you didn't leave enough space and/or went too fast. There is no possible way you can make an exception to that.

Yes, and people often do not leave enough room. Average reaction for a person to see a situation, make a decision, and move the foot from gas to brake is something like 1.5 seconds (I'm talking just some joe off of the street who isnt expecting anything). So, it is now being taught that you need 3 second spacing at 35mph, and 5 or 6 second spacing at 65.

Quote from sinbad :

I don't consider that to be coasting if drive is still engaged. Obviously it's part of driving to lift the throttle and gently slow without applying the brake, but taking it out of gear, or declutching for an extended period at 60mph is different.

Ok, thanks for clarifying, you and I just have different definitions for coasting.

I've just leave it in gear with the clutch engaged when I'm braking for a stop light or what ever, then push the clutch in when I feel the fuel injectors turn back on (yes, the CRV is so unrefined that you can actually feel the injecotors turn back on at around 1200-1000rpm) and downshift to what ever gear is appropriate for moving forward again when the light turns green.

Quote from george_tsiros :

most people aren't borgs, thus are using all their attention to look forward, not backward. i mean they don't have eyes on the back of their neck. because they aren't borgs... and borgs have eyes on the back of their neck... because they have machines and they... :/

when i drive, i need 101% attention towards the direction i am driving, because the moment i start paying attention towards where i am NOT driving means that there is an open possibility for something to **** up.

and then the excuse "i just looked for a split second in my rear mirror, honest! i'm a careful driver" somehow i think won't fly.

So what you're saying, is that because you use all of your attention to look forward, everyone else automatically does as well? And that their attention never slips from that? Basically, in your world, nobody ever gets rear ended, or t-boned? You're essentially saying that its better to NOT know whats happening around you, which means that less situational awareness is better? I've never heard of that. I'd guess you always blind merge as well, because heaven forbid you even glance in the mirror.

Quote from speed1 :

Basically, in your world, nobody ever gets rear ended, or t-boned? You're essentially saying that its better to NOT know whats happening around you, which means that less situational awareness is better? I've never heard of that. I'd guess you always blind merge as well, because heaven forbid you even glance in the mirror.

basically, in my world, i have eyes all over the place. i've already avoided being rear ended a lot of times and at situations where being rear ended would be very dangerous.

also when merging it is more than obvious that i do check to see if i may do so.

you making such comments means to me you didn't exactly understand what i exactly mean saying that you need to be looking in the direction you are going.

i don't get on this forum to get into heated arguments with others. life is giving me enough of those without me looking for them. right now what i am saying is that 99% of the time a driver can not afford taking care of things that others should be taking care of... (that is, for example, checking in their rear when they are moving forward. even a 1 second glance throws away the perception of speed estimation you have for the front, there is much more lost than just that 1 second) even thought that is what i am doing whenever i am driving myself... i can not, however, give this advice to others. that is maybe why driving for me is a rather tiring matter. i have to be constantly aware of the traffic around me, always have a safe way out, always make sure that i can predict what others do, reckognize difficult or unknown situations... that's why i paid half a grand to take safe driving and advanced control classes and why i will do so again in the future as soon as i have money. i am not a good racer but i may say for myself that i am a very safe driver.

Defensive driving is taught when you learn to drive over here as it is considered to minimises road rage and risk. However most people throw it out of the window once they cut off the L plates.

As for the rear driver always at fault when it comes to shunts. I assume you've never had anyone "brake test" you on the motorway? I have come inches from going up the back end of some twit who thought it'd be funny to drive round me, cut back in stupidly close then jump on the anchors.

God only knows why any sane person would want to do it (if you ignore insurance fraud) as it puts a lot of people in danger.

Quote from gezmoor :

Tosh. That's rubbish, sorry. It's a rule that was made up by Insurance companies to make their job easy, not because it has any genuine merit.

The "theory" being if you are driving slow enough, with enough space and being attentive you should never hit the person in front. But the reality isn't like that. Driving on the road is only possible if people behave in predictable ways. If someone emergency stops in front of you for no reason you're going to tail end them. End of story. Why? because its IMPOSSIBLE to have a large enough gap between you and the vehicle in front in the real world. Why? because someone will pull in front of you and fill it. So what are drivers expected to do? keep backing off and end up going backwards?

Sorry but in the real world, a more pragmatic approach is called for. Over simplistic "rules" that don't fit with reality only suit certain parties, and have no basis in truth with regard to finding fault.

Come and try driving in London for a day and see how far you get with your simplistic idealistic point of view.

Since I got my licence I've had enough idiots slamming on the brakes for no good reason right in front of me, thank you very much... Still, I always stopped in time... I also don't recall going backwards, at least not without the others breaking the speed limit...

Quote from speed1 :

Actually, thats by definition defensive driving, or paying attention to traffic around you. Anytime I hit the brakes, I subconsciously glance in my rear view mirror to see what traffic behind me is doing. Judging from that statement you made, I'm sure (whether of not you admit it), you just go when the light turns green. Admittedly, I often do as well, but I've avoided being hit by a light runner at least twice now by looking left and right. You've got to remember, I live in America, the home of some of the worst imaginable drivers. You've got to watch for dumbasses texting, dumbasses reaching for something on the floor, dumbasses doing makeup, dumbasses that are drunk, and so on.

I differentiate between being aware of one's surroundings and frantically checking every direction for some idiot... I guess driving standards and enforcement of red lights might be better over here...

Quote from george_tsiros :

i don't get on this forum to get into heated arguments with others. life is giving me enough of those without me looking for them. right now what i am saying is that 99% of the time a driver can not afford taking care of things that others should be taking care of... (that is, for example, checking in their rear when they are moving forward. even a 1 second glance throws away the perception of speed estimation you have for the front, there is much more lost than just that 1 second)

First off, I had not realized that this was a heated argument. I dont watch my mirrors, I glance at them (as I was trained to do). You cant honestly rely on other drivers to do anything. I'm not saying everyone is a bad driver, I'm just saying that its fairly good practice to drive like everyone is out to get you.

Quote from bbman :

I differentiate between being aware of one's surroundings and frantically checking every direction for some idiot... I guess driving standards and enforcement of red lights might be better over here...

I see that you live in Austria. What does it take to get a license there? Here, if you're over 18, you take an extremely easy basic knowledge test to get you temp. permit, then you can go back the next day (without any further education or instruction) to take another extremely easy written test, and a 2-5 minute on road driving test (which is also extremely easy, mine involved driving through a neighborhood and back to the DMV, I didnt even have to go through a 4 way intersection or traffic light) and then a maneuverability test (if you fail your drivers test here, for some reason it is almost always on maneuverability despite the fact that most people take the test on very small sedans). So to summarize, it is extremely easy to get a license in the US without any formal instruction. Part of my paranoia could be related to the fact that I drive to my school from time to time. On a bad day in that parkinglot, there are 3-5 fender bender accidents, and frequently much larger crashes. Its like driving in a city of people with an attention span of 10 seconds max.

Quote from speed1 :

What does it take to get a license there?

I'm just explaining the normal way to obtain a licence: First, you need quite some money (~ € 1000.00), then you have to learn the theory part and drive at least 18 hours with an instructor in the car, 1 hour highway and another one night driving included... When you turn 18 (you can start learning before) and an appointed doctor signs you fit for driving (no critical conditions - if your eyesight is too bad you might have to wear glasses mandatory when in the car), you are then allowed to take the theoretical test and if you pass, two weeks later you can take your practical test, which involves a bit of driving in normal traffic (~ 10 min.) and some exercices like parking and slalom around cones. Pass it and you get your licence.

For a few years now they included mandatory "Feedback-Drives" like in Finland after you've gotten your licence. You can't fail them, but you have to show up for it: 3 months after getting your licence first "Feedback-Drive", 3 months later half a day driver safety training and another 3 months later the second "Feedback-Drive".