Slight rant warning : Dad and I.
Discussion
You may find this article about brake specific fuel consumption helpful. If nothing else it'll make conversations between the OP and their dad more interesting.
tl;dr - If you're going from 30 to 60 mph the most fuel efficient way is to do so with the throttle fully open but to change up before you get excessive losses from friction.
Given that I have very little mechanical knowledge, I have found this article useful in convincing myself that the most fuel efficient way to drive is to floor it in third then block change when I reach 60mph.
Which is probably b
ks but I'm quite happy with my delusion.
tl;dr - If you're going from 30 to 60 mph the most fuel efficient way is to do so with the throttle fully open but to change up before you get excessive losses from friction.
Given that I have very little mechanical knowledge, I have found this article useful in convincing myself that the most fuel efficient way to drive is to floor it in third then block change when I reach 60mph.
Which is probably b
ks but I'm quite happy with my delusion.Himself said:
VinceFox said:
KardioKate said:
Himself said:
I fail to see how you're losing out?
You've missed the point completely.
KardioKate said:
Actually I was hoping the thread might stimulate some discussion on gear changing techniques.
You seemed more focused on how to use the engine, rather than gear changing techniques.How does his fuel consumption compare with those listed on the HonestJohn Real MPGs website?
KardioKate said:
I honestly get better results if I get the accelerating out of the way, and then block change into 5th to cruise, than getting into 5th as quickly as I possibly can.
Ok, this is what I can find in your OP that you want comment on I think. But sadly I can't quite make out the question. That's probably because I am an obtuse (old) dipst.So what was your question again?
Bert
KardioKate said:
BertBert said:
what's this got to do with Advanced Driving (the forum title)?
Because he is pretty much questioning the techniques I was taught in the IAM?If driving to AD then safety will be maintained as well as getting better mpg than many other styles of driving
The choice all comes down to what the driver chooses to put first - safety or mpg
Ask DAD what he puts first
A previous boss of mine had one of those stupid management books (he even insisted on lending it to me) called "Don't Sweat The Small Stuff" [1]. That's the gist of most of the advice on here.
Seriously if you want uber MPG, you need to drive differently, pump up (or even change) your tyres, fiddle with your engine management, accelerate like an oil tanker, coast down hills, use miles of forward vision to avoid ever having to brake, and completely switch off your brain (apart from the last point).
But you're an advanced driver, and that's not how you do things. You want to be involved with the driving process. You want to make progress. You can still obtain perfectly respectable MPG figures, as you've demonstrated. The other 4 mpg (debatable since it's not even measured in the same car) is the reward for completely spoiling your driving. Don't do it. As others have said, drive your way, don't drive his car, don't enter into discussions about driving, consider leaving home
IMHO block changing up the box will save nothing in mpg terms, most likely, since manufacturers carefully choose the gear ratios in their cars to give smooth acceleration with reasonable economy with all gears in use. Most likely by using 3rd for longer you're wasting the economy you then achieve by using 5th, and you may be using 5th too soon to be economical, even then.
[1] - it was a crap book, don't even bother looking
Seriously if you want uber MPG, you need to drive differently, pump up (or even change) your tyres, fiddle with your engine management, accelerate like an oil tanker, coast down hills, use miles of forward vision to avoid ever having to brake, and completely switch off your brain (apart from the last point).
But you're an advanced driver, and that's not how you do things. You want to be involved with the driving process. You want to make progress. You can still obtain perfectly respectable MPG figures, as you've demonstrated. The other 4 mpg (debatable since it's not even measured in the same car) is the reward for completely spoiling your driving. Don't do it. As others have said, drive your way, don't drive his car, don't enter into discussions about driving, consider leaving home
IMHO block changing up the box will save nothing in mpg terms, most likely, since manufacturers carefully choose the gear ratios in their cars to give smooth acceleration with reasonable economy with all gears in use. Most likely by using 3rd for longer you're wasting the economy you then achieve by using 5th, and you may be using 5th too soon to be economical, even then.
[1] - it was a crap book, don't even bother looking
I have a 2008 1.4 SEAT IBIZA sport
At 2500 revs is does 10 in 1st, 20 in 2nd, 30 in 3rd, 40 in 4th and 50 in 5th which means I can drive using the gears and rev counter in many cases !!
I usually change up to the next gear as low as 2000 revs or up to 3500 revs depending on circumstances
2000 rev upchange if got plenty of time and save fuel by very gentle use of the accelerator
3500 rev upchange to really get a move on/progressive driving
Downchanging gears is done by block changing
Gears for go and brakes for slow - very easy to do for a learner or an advanced driver
SAFEST way to downchange in normal driving conditions is to have the car 'balanced' so no bonnet dipped and that means releasing the brake pedal to do that - it also means that both hands remain on the wheel whilst braking
That does not mean other methods are necessarily UNSAFE
At 2500 revs is does 10 in 1st, 20 in 2nd, 30 in 3rd, 40 in 4th and 50 in 5th which means I can drive using the gears and rev counter in many cases !!
I usually change up to the next gear as low as 2000 revs or up to 3500 revs depending on circumstances
2000 rev upchange if got plenty of time and save fuel by very gentle use of the accelerator
3500 rev upchange to really get a move on/progressive driving
Downchanging gears is done by block changing
Gears for go and brakes for slow - very easy to do for a learner or an advanced driver
SAFEST way to downchange in normal driving conditions is to have the car 'balanced' so no bonnet dipped and that means releasing the brake pedal to do that - it also means that both hands remain on the wheel whilst braking
That does not mean other methods are necessarily UNSAFE
R0G said:
I have a 2008 1.4 SEAT IBIZA sport
At 2500 revs is does 10 in 1st, 20 in 2nd, 30 in 3rd, 40 in 4th and 50 in 5th which means I can drive using the gears and rev counter in many cases !!
I usually change up to the next gear as low as 2000 revs or up to 3500 revs depending on circumstances
2000 rev upchange if got plenty of time and save fuel by very gentle use of the accelerator
3500 rev upchange to really get a move on/progressive driving
Downchanging gears is done by block changing
Gears for go and brakes for slow - very easy to do for a learner or an advanced driver
SAFEST way to downchange in normal driving conditions is to have the car 'balanced' so no bonnet dipped and that means releasing the brake pedal to do that - it also means that both hands remain on the wheel whilst braking
That does not mean other methods are necessarily UNSAFE
heel 'n' toe? saves the clutch a bit too and using gears to slow saves fuel as well. Is this sort of thins taught by IAM types?At 2500 revs is does 10 in 1st, 20 in 2nd, 30 in 3rd, 40 in 4th and 50 in 5th which means I can drive using the gears and rev counter in many cases !!
I usually change up to the next gear as low as 2000 revs or up to 3500 revs depending on circumstances
2000 rev upchange if got plenty of time and save fuel by very gentle use of the accelerator
3500 rev upchange to really get a move on/progressive driving
Downchanging gears is done by block changing
Gears for go and brakes for slow - very easy to do for a learner or an advanced driver
SAFEST way to downchange in normal driving conditions is to have the car 'balanced' so no bonnet dipped and that means releasing the brake pedal to do that - it also means that both hands remain on the wheel whilst braking
That does not mean other methods are necessarily UNSAFE
R0G said:
How does using the gears to slow save fuel???
Perhaps a reference to the engine using less fuel on the over-run than on tickover?Rightly or wrongly, driving a 3.6l about, I don't get too concerned with the finer aspects of fuel consumption. If I want to save fuel, I just drive the Galaxy Diesel.
R0G said:
R300will said:
''' using gears to slow saves fuel as well. Is this sort of thins taught by IAM types?
How does using the gears to slow save fuel???Your dad needs to know foot firm down on the throttle to get up to speed as quickly as possible is the most efficient way to drive. Slow acceleration means you take longer moving 2 tonnes of car up to speed.
That also means he needs to anticipate when he can give it full throttle once the car in front is far enough down the road.
Then obviously highest gear lowest rpm without labouring and cruise off throttle to slow down and light loading.
I enjoy my 350bhp and for economy drive my wife's god awful hybrid company car she's been lumbered with. Hopefully for not much longer, it's so dull you may as well play the economy game. No issues achieving 70+ mpg average. Even 62mpg on a 400 mile round trip up the m-way to north Wales. Zzzz
That also means he needs to anticipate when he can give it full throttle once the car in front is far enough down the road.
Then obviously highest gear lowest rpm without labouring and cruise off throttle to slow down and light loading.
I enjoy my 350bhp and for economy drive my wife's god awful hybrid company car she's been lumbered with. Hopefully for not much longer, it's so dull you may as well play the economy game. No issues achieving 70+ mpg average. Even 62mpg on a 400 mile round trip up the m-way to north Wales. Zzzz
Edited by briers on Monday 28th May 21:03
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