Question on gears

[EazyE16]

So i have a Corsa B and im learning to drive.
Often when im doing 30 my dad will say to put it in 4th or even 5th gear as it saves petrol. The corsa can easily drive even at about 25mph in 5th, and i can see how i could save petrol as it would be doing less revs, but is it safe to do that or will it damage the engine?

 

[Focus Owner]

i would say it wont damage the engine as long as you don't strain the engine too much
your dad is correct sounds like my driving instructor

I'm guessing when you go below 20mph you will have bad vibrations in 5th
that might damage the engine

someone else will post who is much more knowledgeable

 

[FDF]

At 30 I think its more comfortable to be in 3rd rather than 4th, depends on the car really. I wouldn't use 5th at 20 mph, cause some juddering I would think in a Corsa. I wouldn't worry too much about fuel consumption while you're learning, its more important to learn to drive safely and smoothly. If your instructor hasn't said anything about it then don't worry. Do what your instructor tells you and remember your dad has probably picked up a few driving bad habits, you don't want to learn his bad habits.

Driving for 23 years and still a clean license

 

[MisssportyGT]

I used 5th gear now all time when i can but i mostly drive at around 35-40mph in towns etc.

With my instructor i always just went to 4th they only want to see you use your 5th gear on a dual carriage way.

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[Most Easterly Pandas]

I always use the highest gear when ever possible and I'm not thrashing it, but I now have an auto, so it dosen't matter

 

[Tris Harris]

at that speed the engine will be labouring and therfore using more fuel in 5th. 4th at 30mph would be better, and 3rd for any lower than 25-27

 

[Andy Monty]

problem with 5th is that you have no power available to get yourself out of trouble where as in 3rd at 30mph and 4th(at 40mph ish) you have a bit of poke in reserve to get yourself out of trouble..

then again the new driving test includes an eco section so check with your instructor

 

[JFL]

i usually go on...

upto 10mph - 1st
10mph to 20mph - 2nd
20mph to 30mph - 3rd
30mph to 40mph - 4th
40mph + - 5th

these will obviously vary depending on how im driving etc, such as overtaking , or creeping round in 2nd gear, sometimes i do 34/35 in 5th

 

[Most Easterly Pandas]

at that speed the engine will be labouring and therfore using more fuel in 5th. 4th at 30mph would be better, and 3rd for any lower than 25-27

All depends upon the gear ratio as to if it's labouring or not.

Out if interest, how does labourung use more fuel

 

[Thewitt]

No problem with just cruising along at 30-40mph in 5th, it will be saving fuel, just remember to change down if you need to accelerate for any reason as you will be using more fuel in 5th gear than say 3rd as there will be more strain on the engine in the higher gear.

 

[Most Easterly Pandas]

No problem with just cruising along at 30-40mph in 5th, it will be saving fuel, just remember to change down if you need to accelerate for any reason as you will be using more fuel in 5th gear than say 3rd as there will be more strain on the engine in the higher gear.

Since when? They say change up gear asap if trying to be really eco.

 

[Munkul]

as long as you have power, the engine isnt juddering and the revs arent dropping off, you can drive in any gear really.

i drive in 6th in 30 zone usually, with revs round about 1500-1700 which is JUST enough power to drive without juddering

 

[SeicentoS]

I chuck the clio in 6th as soon as it hits 20mphish (2.0L engine) and the starlet in 5th as soon as I hit 20 aswell, neither car struggles to do this and I always try and drive in highest gear possible unless I'm doing some spirited driving

 

[FDF]

It really does depend on the car, for example in my 20v Marea I can be doing 15mph in 4th and because there is so much power if I put my foot down the car moves smoothly and quickly out of trouble. In my friends 1.4 Toyota the car would just bog down, you would need to be in 2nd or 3rd to move as smoothly and quickly. Depends on engine size and gear ratios, you treat each car differently.

 

[Singh!]

I never really go into 5th untill im doing 40mph plus... there just isnt enough power as i live in a reasonably hilly area its fine when going downhill but as soon as you get to a slight incline 3rd is needed lol
Fuel consumption doesnt really depend on the revs entirely.. its more to do with the throttle position... for example i can get 45mpg doing 40mph in third or fifth just depends how much im pressing the throttle..
In third you are barely touching it as its in the power band.. whereas in fifth you are pressing the throttle more to keep at that speed.
Sorry if this has confused you but its not as simple as being in the highest gear all the time, ... its also useful to look at your mpg readings as you are driving from time to time to see how the throttle position and gear selection change the reading.

 

[sludgeguts]

Since when? They say change up gear asap if trying to be really eco.

You missed out the most important part when youconverted some text to bold...
just remember to change down if you need to accelerate for any reason as you will be using more fuel in 5th gear than say 3rd as there will be more strain on the engine in the higher gear.

As fiatdrivingfan says, you must treat each car differently.
but also each scenario is different.
30mph on the flat with just you in the car & you may get away with 5th gear. adjust the incline or add a passenger & things may be different.

Manufacturers put many gadgets on cars yet miss out a very important one - the vacuum guage.
A great device that can train you to keep your foot off the accellerator enough to save you fuel.

As an example, try cycling in gear 21 along a flat road - easy? Possibly, but you also need to go fairly fast to keep it easy.
Try cycling slower in the same gear. You can still do it but it will require a little more effort - why? same flat road, same gear.
OK, try going from the slower speed to the faster (more comfortable) speed & it will require a huge effort to get there.
It is the same with the car engine. With the vacuum guage, I noticed I could lose 400rpm at 70mph when I changed from 4th to 5th yet when I came to an incline I couldn't hold the roadspeed & rpm whilst in 5th, I would need to drop back to 4th or increase rpm (and put the guage into the red - using more fuel).
You wouldn't notice this labouring in modern cars because the electronics would compensate - hence why many modern cars will happily cruise at 70 in 5th & rapidly accelerate to allow you to overtake.

With the vacuum guage, you could also see that it was acceptable to drive at 30mph in 3rd gear (and still keep economy), giving you the option of allowing the engine to brake the speed or a bit extra poke when you need to pull out (obviously then changing up).
I doubt you could fit these things to modern engines but I'm sure they could fit an electronic equivalent & plumb it in to the various sensors, it certainly helped me control my right foot.

 

[fenton_jd]

I find that if I'm doing 50mph in my GP and leave it in 4th, the car will maintain that speed with only the very lightest pressure on the accelerator and show an almost constant MPG readout between 70-80mpg, however, if I put into 5th, I have to press that little bit harder on the accelerator to maintain 50mph, and the mpg drops down to 40-50mpg.

Appears that if you have the engine smack in the powerband (on my GP that's 3.5k), then it takes very little effort to maintain speed, therefore saving petrol Methinks anyway.

 

[Singh!]

I find that if I'm doing 50mph in my GP and leave it in 4th, the car will maintain that speed with only the very lightest pressure on the accelerator and show an almost constant MPG readout between 70-80mpg, however, if I put into 5th, I have to press that little bit harder on the accelerator to maintain 50mph, and the mpg drops down to 40-50mpg.

Appears that if you have the engine smack in the powerband (on my GP that's 3.5k), then it takes very little effort to maintain speed, therefore saving petrol Methinks anyway.

Yeh exactly my point

 

[Singh!]

You missed out the most important part when youconverted some text to bold...
just remember to change down if you need to accelerate for any reason as you will be using more fuel in 5th gear than say 3rd as there will be more strain on the engine in the higher gear.

As fiatdrivingfan says, you must treat each car differently.
but also each scenario is different.
30mph on the flat with just you in the car & you may get away with 5th gear. adjust the incline or add a passenger & things may be different.

Manufacturers put many gadgets on cars yet miss out a very important one - the vacuum guage.
A great device that can train you to keep your foot off the accellerator enough to save you fuel.

As an example, try cycling in gear 21 along a flat road - easy? Possibly, but you also need to go fairly fast to keep it easy.
Try cycling slower in the same gear. You can still do it but it will require a little more effort - why? same flat road, same gear.
OK, try going from the slower speed to the faster (more comfortable) speed & it will require a huge effort to get there.
It is the same with the car engine. With the vacuum guage, I noticed I could lose 400rpm at 70mph when I changed from 4th to 5th yet when I came to an incline I couldn't hold the roadspeed & rpm whilst in 5th, I would need to drop back to 4th or increase rpm (and put the guage into the red - using more fuel).
You wouldn't notice this labouring in modern cars because the electronics would compensate - hence why many modern cars will happily cruise at 70 in 5th & rapidly accelerate to allow you to overtake.

With the vacuum guage, you could also see that it was acceptable to drive at 30mph in 3rd gear (and still keep economy), giving you the option of allowing the engine to brake the speed or a bit extra poke when you need to pull out (obviously then changing up).
I doubt you could fit these things to modern engines but I'm sure they could fit an electronic equivalent & plumb it in to the various sensors, it certainly helped me control my right foot.

lol thats what i was trying to get at but couldnt get it down that well , btw ive never seen one of those vacuum guages.. what cars were they in?

 

[Most Easterly Pandas]

OMG I'm really sort of lost, but sludge guts, the bit about the bike gears helped make me understand I think