Go Back   The 75 and ZT Owners Club Forums > The 75 and ZT Owners Club Forums > Technical Help Forum
Register FAQ Image Gallery Members List Calendar Mark Forums Read
Notices

Reply
 
Thread Tools Display Modes
Old 22nd April 2022, 22:27   #61
macafee2
This is my second home
 
Rover 75 Saloon & Tourer

Join Date: Sep 2012
Location: Lincoln
Posts: 14,890
Thanks: 1,630
Thanked 3,032 Times in 2,181 Posts
Default

Quote:
Originally Posted by lipsee View Post
I just waded though 6 pages of claptrap,,, in answer to the buss driving instructor DD busses get just about the worse fuel figures on this planet,,and all that stopping and starting plays hell with the brakes... Now all you old boys still driving old Fodens and ERFs and do,nt mentions Borderers ,those trucks where slow and the brakes where NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-NAUGHTY WORD-,so of course you had to use the box to slow down,,modern trucks with auto boxes and very powerful brakes ,you still need to drop a gear but you can rely on the brakes .. The technique I use in my tourer auto deisel is this .. I accelerate slowly until about 50mph when the box changes into top,then I can press harder until 60/70mph ,then put on CC... Slowing I knockoff CC change to gear manually into forth ,slow down (no brakes ) then third at about 45/50 ,revs go to about 3000. For about the last 8years I,v been driving my 75 from London to Lincs over night ,so I get chance to really drag out a good fuel figure (47mpg if you are interested(on the A1) Having just retired after "yes" 50 years ,and after driving just about everything there is to drive I prefer the old fashion way ( gears brakes,mirrror signal maneuver )not always in that order mind...regards all

someone that drives an auto and engine brakes, now that is as rare as a month of Sundays. I have never been in an auto driven by someone else where they have engine braked. I dont think most drivers of autos know that they can engine brake. I was going to ask is those that drive autos engine brake.

macafee2
macafee2 is offline   Reply With Quote
Old 23rd April 2022, 11:20   #62
SD1too
Doesn't do things by halves
 
SD1too's Avatar
 
Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model.

Join Date: Mar 2007
Location: Former Middlesex
Posts: 20,265
Thanks: 1,587
Thanked 3,749 Times in 3,181 Posts
Default

Quote:
Originally Posted by macafee2 View Post
I dont think most drivers of autos know that they can engine brake.
Hi Ian,

Of course as speed reduces during braking the automatic gearbox will change down in most (but not all) cases. This is usually imperceptible but confirmed by the lack of an uncomfortable downchange when reapplying power.

Simon
__________________
"Whatever is rightly done, however humble, is noble."
Sir Henry Royce.
SD1too is offline   Reply With Quote
Old 23rd April 2022, 17:52   #63
bl52krz
This is my second home
 
bl52krz's Avatar
 
Rover 75 cdt club + Rover 2.5 KV6 Conni SE

Join Date: May 2008
Location: Birmingham
Posts: 11,356
Thanks: 6,587
Thanked 2,262 Times in 1,729 Posts
Default

All this gobbledegook about ‘block changing’ , proves what we older drivers know. That if you are not in the right gear, at the right time, you are not ‘in charge’ of your vehicle. I was taught by an omnibus (bus) inspector in the late 50s. He was our next door neighbour. He sat in my vehicle for around an hour and a half telling me about driving, and the techniques involved. One of the lessons was about ‘using the gearbox to not only accelerate, but to slow down when coming to traffic lights, stop signs and the like. Perhaps some clever person can tell me how you can still be ‘in control’ of your vehicle, if you are not in the correct gear for a set speed at which you are travelling? You can not be still ‘in charge’ of your vehicle if you are not in a gear that corresponds to the speed you are travelling at. I.E. block changing from 4-2 or 3-1. Load of utter rubbish, and if as has been stated on here, it is taught by people teaching people learning to drive, then it flies in the face of sensibility, and should be omitted from any test ,while taking a road test to gain a licence.
__________________
Great Barr, Birmingham.
bl52krz is offline   Reply With Quote
Old 23rd April 2022, 18:27   #64
SD1too
Doesn't do things by halves
 
SD1too's Avatar
 
Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model.

Join Date: Mar 2007
Location: Former Middlesex
Posts: 20,265
Thanks: 1,587
Thanked 3,749 Times in 3,181 Posts
Default

Quote:
Originally Posted by bl52krz View Post
All this gobbledegook about ‘block changing’ , proves what we older drivers know. That if you are not in the right gear, at the right time, you are not ‘in charge’ of your vehicle.

Absolutely right David. Unfortunately we are in an era where the policymakers think that the wheel needs to be reinvented. In an earlier post I described a common situation where "block changing" does not leave the driver in proper control of the vehicle, whereas the way you and I were taught leaves us prepared for any eventuality.

Simon
__________________
"Whatever is rightly done, however humble, is noble."
Sir Henry Royce.
SD1too is offline   Reply With Quote
Old 25th April 2022, 16:57   #65
Torqueofthedevil
Avid contributor
 
Wedgwood Blue 75 Connoisseur saloon, Duotone 75 Connoisseur saloon. Former ZT190 and ZT260 owner

Join Date: Oct 2021
Location: Salop
Posts: 145
Thanks: 367
Thanked 40 Times in 29 Posts
Default

Quote:
Originally Posted by guru View Post
Yep never coast, always leave it in gear as the ECU will shut off the fuel supply whereas when coasting it's still using fuel to keep the engine spinning.
But the engine is still sipping fuel when left in gear! Otherwise it would stop! Nothing wrong with coasting, makes perfect sense in some situations and I'm not at all convinced that the supposed safety concerns have any validity.
Torqueofthedevil is offline   Reply With Quote
Old 25th April 2022, 17:56   #66
SD1too
Doesn't do things by halves
 
SD1too's Avatar
 
Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model.

Join Date: Mar 2007
Location: Former Middlesex
Posts: 20,265
Thanks: 1,587
Thanked 3,749 Times in 3,181 Posts
Exclamation

Quote:
Originally Posted by Torqueofthedevil View Post
Nothing wrong with coasting ...
Hello Charlie,

Coasting, that is making progress with the engine disconnected from the driving wheels, is actually dangerous. Braking distances are increased markedly together with the tendency for the car to understeer to an alarming degree.

What is the point of it?

Simon
__________________
"Whatever is rightly done, however humble, is noble."
Sir Henry Royce.
SD1too is offline   Reply With Quote
Old 26th April 2022, 07:07   #67
macafee2
This is my second home
 
Rover 75 Saloon & Tourer

Join Date: Sep 2012
Location: Lincoln
Posts: 14,890
Thanks: 1,630
Thanked 3,032 Times in 2,181 Posts
Default

Quote:
Originally Posted by SD1too View Post
Hi Ian,

Of course as speed reduces during braking the automatic gearbox will change down in most (but not all) cases. This is usually imperceptible but confirmed by the lack of an uncomfortable downchange when reapplying power.

Simon
That is not engine braking as I know it. In an auto you can move the gear lever sideways and then push the gear lever forward to change down, you then release it and by either pushing forward again or pulling back will change down or up. Some autos have paddles on the steering column, one for changing down and one for changing up.

I was assuming lipsee was using one of these two methods.

macafee2
macafee2 is offline   Reply With Quote
Old 26th April 2022, 07:13   #68
macafee2
This is my second home
 
Rover 75 Saloon & Tourer

Join Date: Sep 2012
Location: Lincoln
Posts: 14,890
Thanks: 1,630
Thanked 3,032 Times in 2,181 Posts
Default

Quote:
Originally Posted by Torqueofthedevil View Post
But the engine is still sipping fuel when left in gear! Otherwise it would stop! Nothing wrong with coasting, makes perfect sense in some situations and I'm not at all convinced that the supposed safety concerns have any validity.
I dont think the engine with fuel injection consumes more fuel then at tick over. It does not draw fuel, fuel is forced into the engine by throttle position and a closed throttle will not send fuel above the tick over amount to the engine.

If you dont think coasting is a safety concern, go somewhere quiet and see what cornering speeds you can achieve coasting and driving around the corner. Worse, is part way round the corner is to coast. You need to be going at speed so you need a big un off area. Try it.

macafee2
macafee2 is offline   Reply With Quote
Old 26th April 2022, 11:44   #69
Torqueofthedevil
Avid contributor
 
Wedgwood Blue 75 Connoisseur saloon, Duotone 75 Connoisseur saloon. Former ZT190 and ZT260 owner

Join Date: Oct 2021
Location: Salop
Posts: 145
Thanks: 367
Thanked 40 Times in 29 Posts
Default

Quote:
Originally Posted by macafee2 View Post
I dont think the engine with fuel injection consumes more fuel then at tick over. It does not draw fuel, fuel is forced into the engine by throttle position and a closed throttle will not send fuel above the tick over amount to the engine.

If you dont think coasting is a safety concern, go somewhere quiet and see what cornering speeds you can achieve coasting and driving around the corner. Worse, is part way round the corner is to coast. You need to be going at speed so you need a big un off area. Try it.

macafee2
I'm not going to try it, because cornering isn't a situation where I would let a car coast! Likewise, if I'm coasting and something happens and I need to brake, I can put the car back into gear in less than a second. But as per my previous post, in some situations (eg no corners, empty road - half a mile from a roundabout on a quiet dual carriageway might be one example) I don't see any harm in it at all.
Torqueofthedevil is offline   Reply With Quote
Old 26th April 2022, 11:46   #70
Torqueofthedevil
Avid contributor
 
Wedgwood Blue 75 Connoisseur saloon, Duotone 75 Connoisseur saloon. Former ZT190 and ZT260 owner

Join Date: Oct 2021
Location: Salop
Posts: 145
Thanks: 367
Thanked 40 Times in 29 Posts
Default

Quote:
Originally Posted by SD1too View Post
Hello Charlie,

Coasting, that is making progress with the engine disconnected from the driving wheels, is actually dangerous. Braking distances are increased markedly together with the tendency for the car to understeer to an alarming degree.

What is the point of it?

Simon
I would suggest simply to slow down gradually, making best use of the car's momentum while using minimal fuel, in a situation where best brake performance and cornering ability aren't needed.
Torqueofthedevil is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 05:37.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © 2006-2023, The Rover 75 & MG ZT Owners Club Ltd