Is engine braking good or bad?

[trashbat]

otolith said:

Similar to the IAM/RoSPA stance on using lower gears in urban limits, sacrificing some fuel economy for better control - although I do remember seeing one of those organisations being quoted as saying that there was no economy cost, which isn't the case in any car I've measured it in!

There's a can of worms

FWIW I do this, but I can't fully understand why they recommend it. The ultimate purpose appears to be facilitating prompt acceleration out of a hazard in an environment where you are likely already going at the speed limit - thus illegal.

Edit: or is the motive also connected to engine braking?

[GokTweed]

trashbat said:

otolith said:

Similar to the IAM/RoSPA stance on using lower gears in urban limits, sacrificing some fuel economy for better control - although I do remember seeing one of those organisations being quoted as saying that there was no economy cost, which isn't the case in any car I've measured it in!

There's a can of worms

FWIW I do this, but I can't fully understand why they recommend it. The ultimate purpose appears to be facilitating prompt acceleration out of a hazard in an environment where you are likely already going at the speed limit - thus illegal.

Edit: or is the motive also connected to engine braking?

A few years back when i was learning my instructor said '30 in 3rd' which i never do as it's just daft for economy purposes IMO. His reasoning was that with most cars 30 in 3rd means the engine's doing around 2000-3000rpm and so it makes a noticeable sound and therefore you end up thinking you're going fast enough. In 4th or 5th (depending on ratios etc.) the engine isn't making nearly as much noise and so you are more likely to push over 30mph.

[SpeedMattersNot]

What if you drive an electric car? :P

[7mike]

trashbat said:

here's a can of worms

FWIW I do this, but I can't fully understand why they recommend it. The ultimate purpose appears to be facilitating prompt acceleration out of a hazard in an environment where you are likely already going at the speed limit - thus illegal.

I'd prefer to think that the use of a ratio that offers a degree of flexibility, given the constantly changing environment, is worth hanging on to if the alternative is lots of gear changing. Watching some drivers (especially now their car tells them when to change up!) is like watching them paddle a canoe .Excessive gear changing does screw up mpg.

[jbsportstech]

davepoth said:

There certainly is that.

On the motorway I try as hard as I can to avoid the brake pedal, as I know cars behind will always brake harder than I have, causing the ripple effect. In fact whenever I get on the brakes on the motorway I have one hand hovering over the hazard switch just in case of coming to a complete stop sharpish.

It waste fuel causes unnecessary wear, but if its your bag.

I heel and toe but take the gear I need not 4 I didn't first,.

[jbsportstech]

GokTweed said:

A few years back when i was learning my instructor said '30 in 3rd' which i never do as it's just daft for economy purposes IMO. His reasoning was that with most cars 30 in 3rd means the engine's doing around 2000-3000rpm and so it makes a noticeable sound and therefore you end up thinking you're going fast enough. In 4th or 5th (depending on ratios etc.) the engine isn't making nearly as much noise and so you are more likely to push over 30mph.

I sometime use 3 or 4, Chris Gilbert uses 4 if the conditions and view allow and clearly states getting economy were he can in a 30 but if in a more closed up scenario he take 3rd for more flexibility if you explain it in commentary I see no issue on a test.

It guidelines you are allowed to decide for yourself what is best in individual circumstances.

[7mike]

jbsportstech said:

I sometime use 3 or 4, Chris Gilbert uses 4 if the conditions and view allow and clearly states getting economy were he can in a 30 but if in a more closed up scenario he take 3rd for more flexibility if you explain it in commentary I see no issue on a test.

It guidelines you are allowed to decide for yourself what is best in individual circumstances.

It's ages since I watched that video, if I remember rightly he goes into 4th just long enough to comment on his token gesture towards saving the planet before sticking it back down again

[GokTweed]

SpeedMattersNot said:

What if you drive an electric car? :P

You'll be lucky to hit 30mph!

[davepoth]

jbsportstech said:

davepoth said:

There certainly is that.

On the motorway I try as hard as I can to avoid the brake pedal, as I know cars behind will always brake harder than I have, causing the ripple effect. In fact whenever I get on the brakes on the motorway I have one hand hovering over the hazard switch just in case of coming to a complete stop sharpish.

It waste fuel causes unnecessary wear, but if its your bag.

I heel and toe but take the gear I need not 4 I didn't first,.

I'm "practicing".

[anonymous-user]

7mike said:

Excessive gear changing does screw up mpg.

Which is of course why the OEM's are moving towards 8/10 and even 12 speed transmissions to reduce fuel economy! NOT!


Ultimately, i pick the highest gear the car will smoothly carry at what ever speed i am CRUISING at, be that 30, 50, 60 or 70mph. Modern engines have such flat torque curves that being a gear higher isn't a major issue, and tbh, to get any meaningful acceleration to "quickly" avoid a hazard would take 2nd gear (or maybe even 1st gear in some cars).

Also, i find the dial mounted just infront of me, the one with the numbers and the little pointy white stick really useful for telling me how fast i am going...........

It should be noted that at low speeds (<40mph) engine friction if in a lower gear (>3000rpm) is of the same magnitude to road load because hardly any aero load exists (aero = square of vehicle speed).
In effect, drive along in a 30mph zone in 3rd, when you could be in 5th and you will be using the same amount of fuel to just turn your engine around as that which is actually providing useful work and moving your entire car along the road!!

[7mike]

Max_Torque said:

Ultimately, i pick the highest gear the car will smoothly carry at what ever speed i am CRUISING at,

So do I, perhaps we have a different opinion as to what constitutes cruising.

[cupraray]

7mike said:

I recently had to assess a company driver with the 'not my fault' attitude. Recently been involved in several non fault collisions, the last vehicle to go into the back of theirs was a 40t LGV. fking lucky to be alive. Like a few here who pride themselves on their driving skills; competency was never the issue, won't keep them out of bother though.

OP; this is not intended as a dig at you btw.

I wouldn't think you've got the abilities to assess the depth of mud a pig is standing in

[7mike]

cupraray said:

I wouldn't think you've got the abilities to assess the depth of mud a pig is standing in

Fortunately the people who pay me would not agree.

and on that note, I shall cease from feeding the troll

[cupraray]

7mike said:

Fortunately the people who pay me would not agree.

and on that note, I shall cease from feeding the troll

you just have...........So the people who pay you are ok with your mud depth assessing

[SVS]

Come on guys, it's time for some peace and love

cupraray said:

7mike said:

I love you

I love you too.

[BertBert]

I'm quite enjoying the dialogue! I can't work out if it's friends having fun or a bona-fide PH tussle! Excellent work chaps.

[7mike]

BertBert said:

I'm quite enjoying the dialogue! I can't work out if it's friends having fun or a bona-fide PH tussle! Excellent work chaps.

I'm sure you're familiar with some of my posting history BB, and the other guy's contributions since joining in the last month. I'll let you work out the rest. But as I've already said, I shall from now on desist from troll feeding.

[FFMan]

to go back to the original theme of the post, I guess this must have been perceived as a problem by someone at some time as I have in the garage 2 kits of vacuum operated switch which are supposed to activate your brake lights from manifold vacuum.

the trigger point is adjustable and I assumed it was intended for cars with lots of engine braking. 70s automobilia now I think.

[rogerhudson]

Lots of rather odd comments seem to be against engine braking?
One basic rule 'always go down in the same gear you would use to go up that piece of road' is a clear call for engine braking.
I am not a hyper-miler by any means but i always change down early and ease off the throttle and only ever use brakes lightly to stop. Yes, having a steel girder rear bumper does help.

[rogerhudson]

real4star said:

When driving Dads (1960)Land Rover to Tesco in Strood

I go around the one way system in top gear (4th)
Indicate and turn left into the side road after the traffic lights (at McDonalds).
I back nearly all the way off the power to start slowing down and follow the bumpy potholed road around to the right.
I change down into 3rd (still slowing) and indicate right to enter Tesco.
Double de-clutch down into 2nd (no synchro) and make the turn into the carpark.
Double de-clutch into 1st and pootle around to find a parking space.

As I was walking into the store I was stopped by another customer (who followed me in) and was informed he had nearly run into the back of me because 'your brakelights aren't working'.

I didn't brake until I was parked as the speed of travel can be controlled easily with the gears.

Did I do something wrong/illegal or was he just following too close?

Edited by real4star on Saturday 29th December 03:00

Live happily in the knowledge that series land rovers will outlive the shopper hatchback.