How many rev's are enough?
This article is intended to help you to understand how to make the decision about how many engine rev's you need for your current situation
Knowing the precise number of engine revolutions necessary
for each particular situation
is not a mathematical science.
Quite a few modern cars come fitted with rev' counters but these are only of limited use to a learner. This article gives general advice on how to make the decision stated in its own title. Bearing in mind that given circumstances are unlikely to repeat themselves exactly, particularly in traffic, it is not wise to be concentrating on a dial inside the car when something far more important could be happening outside.
Why should I pay particular attention to my engine rev's?
If you do not know how to tell when enough is enough on the gas pedal it is quite possible that your driving style will develop into a haphazard and somewhat jerky affair. This will make your progress through the driving course more problematic when this need not be the case.
Hill starts are an obvious example when the amount of rev's applied is critical but you need to remember that this situation does not only occur when your instructor pulls you into the kerb on an obvious steep hill. There are streets in most towns where as soon as the instructor gives the instruction, 'I would like you to take the next road on the left please', the pupil thinks to themselves, 'hill start coming up!' There are many junctions where the approach is on an a uphill gradient. The procedure here for moving off is that of the hill start but if the pupil does not remember this the end result will often be a stalled engine and a confused pupil. Recognising when extra rev's are necessary can be as hard as judging how many.
Moving away from the kerb in traffic and emerging into a new road are two times when making progress is essential. If you get the engine rev's wrong though there could be plenty of noise and no action, the screech of tyres spinning on the road surface, or of course a stalled engine. Get the combination right however and the result will be something altogether more satisfactory. A smooth progressive increase in speed until a suitable speed is achieved for the conditions on the road.
What makes it so difficult to get right?
Experience helps. At first you will over-rev the engine and probably bring the clutch up too far on the biting point. A jerky start does no harm and will get smoother with practice.
Modern engines are very quiet. This sounds like nonsense at first but when you try to control the rev's you will notice that the sound of the engine does not change very much. Some pupils have private practice available in a different vehicle. This throws in a second set of controls for them to get used to. No two vehicles drive exactly the same. Even if they are the same type of car the settings will be slightly different on the clutch and brake cables leading to a different feel to the operation of the controls. Private practice does bring some control problems initially but the extra experience gained is worth it.
Changes in circumstances on the road can throw the judgement of a beginner. A sudden change in the weather or on a dark night turning into a less effectively lit street can be enough. Your perception of the circumstances around you effects your judgement.
How do I get it right then?
The first and most obvious piece of advice is to start carefully. You are not expected to move away perfectly straight away. Do not be afraid to take a little extra time and get it right. When you are movign off correctly then you can start to perform the procedure a little quicker. When you are introduced to inclined starts (hill starts) then be prepared to slow down again if necessary. For some pupils this is literally like a new beginning for moving away from the kerb. Your instructor will understand this and be patient. They are realists.
Operate the clutch gently! Sounds as obvious as the first piece of advice when you are sitting at a computer reading from the screen but when you are in a car on a hill the tendency for a lot of pupils is to want to get it all over with as quickly as possible. A quickly raised clutch results in either spinning wheels or a stall. Do it gently and you need never experience either.
What about the number of rev's under acceleration?
Just for the sake of example you are sitting at the end of a road waiting for a gap to emerge left at a 'T' junction.
Use first gear as normal. You have still got to move off and steer around the corner accurately. Once you are straight and in second gear if the road ahead is clear then get your foot down. Second gear is very powerful and the source of most of the acceleration that you will use whilst learning. Use second gear up to thirty miles per hour on most cars then change gear to third just to maintain the speed. If the speed limit is higher than thirty then hit the gas again and go for it.
On a straight road with available space you are expected to do a suitable speed for the road. The other road users will be. Remember. When emerging into a new road you must not make the vehicle that you have pulled out infront of change speed or direction at all because of your emerge. In these circumstances acceleration is essential.
When moving away froma stationary position in traffic do not use too many rev's in first gear. It gets very noisy very quickly. Change to secong reasonably soon after moving off, your instructor will help you to judge the exact time as it changes between vehicles, then put your foot down. This is a reasonable use of speed.
Neither your instructor nor your examiner want you to be the slowcoach on the road. You must drive at a suitable speed for the road conditions as they are presented to you on the day. If acceleration is required, hit the gas.
How many rev's should I use in slow moving traffic.
Enough that the gearbox is reasonably quiet. A few more is better than a few less in this circumstance because if there are a few rev's in hand you can slow down further as the traffic ahead of you does without the need for a gear change whereas if you only have very few rev's on you will be changing down gears immediately. Second gear without any rev's will not stall the car on level ground whereas on an uphill stretch of road first would probably be required. Just match the gear to the speed and be prepared to slow down or stop at any time. Good forward planning should be your main focus for this decision. If having a few extra rev's on gives you more options in the traffic then that is the way to go.
In summary: -
To drive a vehicle you need to balance the accelerator at a point where the engine develops enough power to pull the car suitably for the circumstances. That is so easy for me to write but a pain in the bum for you to do. We know that. Hill starts and accelerating away from junctions are chalenges in themselves and at the beginning moving away from the kerb is a mountain that gets climbed quite quickly. In traffic you need to look well ahead to notice changes in traffic speed before the car infront of you stops so that you can drive gently instead of suddenly breaking all the time. Experience and advice are the key elements in getting it right. Listen closely to your instructor. They will give you all of the advice that you need to control their particular vehicle. If you are fortunate enough to have a vehicle available for private practice then you will have to apply the same principles that they teach you in the other vehicle as well.
Good luck.
