Team-BHP > Team-BHP Advice > On owning a car


Reply
  Search this Thread
708,674 views
Old 18th March 2009, 22:52   #286
Senior - BHPian
 
Join Date: Nov 2007
Location: Bangalore
Posts: 3,998
Thanked: 4,180 Times

Quote:
Originally Posted by supremeBaleno View Post
A car engine has the same sound during normal running and during engine braking ie. it sounds 'live' - don't know how to say this. I doubt that it would sound the same way after fuel is cut-off and when no combustion is happening.
True. Another related question is, if there is a fuel cut off and engine is going without firing, and when the engine comes back to life, there should be a jerk or shudder. Like the one you get when you crank the engine or when you push start a car in a slope.
I am not questioning the 'no fuel' theory but I am just curious to know.
Guna is offline  
Old 21st March 2009, 10:12   #287
BHPian
 
Atlblkz06's Avatar
 
Join Date: Jan 2009
Location: Atlanta
Posts: 164
Thanked: 20 Times

I think you guys are nitpicking and hair splitting too much.

Engines really don't use too much gas when just idling. You're better off worrying about DRIVING efficiently. I dont know how it is over there, but here in the US people are so eager to get places that the typical person keeps accelerating and then brakes hard near lights. I get my foot off the gas the second I see a red light and coast to a stop. Then when the light turns green, I respond quickly and accelerate as needed. Most tend to daydream and step hard on the gas which is a waste.

In the end I've noticed that I'm as fast - or faster than these absent minded drivers that dont pay attention. As an added bonus I also get better mileage

One thing about hypermiling - you you think you're earth's best friend, but please remember NOT to piss off other drivers. You may save 1/10th of a gallon on your drive but by pissing of others you're collectively wasting several gallons of gas by making others brake and accelerate when they go around you and the whole point of hypermiling is lost!
Atlblkz06 is offline  
Old 21st March 2009, 13:42   #288
rippergeo
 
Posts: n/a

Quote:
Originally Posted by Atlblkz06 View Post
One thing about hypermiling - you you think you're earth's best friend, but please remember NOT to piss off other drivers. You may save 1/10th of a gallon on your drive but by pissing of others you're collectively wasting several gallons of gas by making others brake and accelerate when they go around you and the whole point of hypermiling is lost!
Finally! someone who gets it! It is true, having someone in the fast lane completing an overtaking maneuver that lasts 30 minutes, just so that he can get the best mileage....

The angrier the driver, the higher the revs.
 
Old 21st March 2009, 13:47   #289
Senior - BHPian
 
Join Date: Sep 2007
Location: New Delhi
Posts: 3,095
Thanked: 303 Times

Quote:
Originally Posted by rippergeo View Post
Finally! someone who gets it! It is true, having someone in the fast lane completing an overtaking maneuver that lasts 30 minutes, just so that he can get the best mileage....
What blasphemy is this?!
Hypermilers do not overtake! They stay in the partial vacuum behind your car!
You'd be lucky if he has the engine turned on, LOL!
anupmathur is offline  
Old 21st March 2009, 14:54   #290
Senior - BHPian
 
supremeBaleno's Avatar
 
Join Date: Dec 2005
Location: Chennai / Kochi
Posts: 5,545
Thanked: 2,693 Times

Quote:
Originally Posted by Atlblkz06
I think you guys are nitpicking and hair splitting too much.
If not for nitpicking, there won't be much activity happening on this forum.

Quote:
Originally Posted by Atlblkz06
Engines really don't use too much gas when just idling. You're better off worrying about DRIVING efficiently.
Idling ? Where did that come from ? We were discussing about engine braking situations. And driving efficiently differs from person to person. The same hypermiling guy you ridiculed must be doing that because he thinks he is driving efficiently.

I am no hypermiler and neither aim to be one, but if there is a way to avoid wastage, I would like to be aware of that, because in all probability, this stuff (gasoline/diesel) is not going to be around when our kids get behind the wheel. No issues with using it, but let us not waste it.
supremeBaleno is offline  
Old 21st March 2009, 15:03   #291
Senior - BHPian
 
Join Date: Sep 2007
Location: New Delhi
Posts: 3,095
Thanked: 303 Times

Quote:
Originally Posted by supremeBaleno View Post
If not for nitpicking, there won't be much activity happening on this forum.
LOL, very true!

But I sometimes back off from this!
anupmathur is offline  
Old 25th March 2009, 14:43   #292
Newbie
 
Join Date: Mar 2009
Location: Banaglore
Posts: 6
Thanked: 0 Times

Hi, I am new to this forum and this is my first post here. I actually have this query and thought that people on this forum would know the answer, I would like to know in the below mentioned situation would there be any impact on the FE or any -ve impact on the engine. Here goes:
You are driving on an open road say at the speed of 100kmph, about 500-600mts away there is a toll booth so you have stop, now if you shift the gear to neutral and drive on for a few hundered mts more and then start braking slowly as you approach the speed breaker, onec you finally reach the speed breaker and move the car in to 2nd gear and on reaching the toll booth you stop the car completely and are back in netural.
Will the car being in neutral and yet running at a speed decreasing from 100-40kmph impact the engine? The decrease in speed could be beacuse of braking or due to loss of momentum as well.
Thanks in advance.
romajoshi is offline  
Old 25th March 2009, 18:00   #293
GTO
Team-BHP Support
 
GTO's Avatar
 
Join Date: Feb 2004
Location: Bombay
Posts: 70,335
Thanked: 298,731 Times

Quote:
Originally Posted by romajoshi View Post
You are driving on an open road say at the speed of 100kmph, about 500-600mts away there is a toll booth so you have stop, now if you shift the gear to neutral and drive on for a few hundered mts more and then start braking slowly as you approach the speed breaker
Firstly, coasting in neutral at 100 kph is dangerous. Second, look up earlier posts on this thread. There is hardly any fuel saving over slowing down in a gear (which is safer as well).

Quote:
Will the car being in neutral and yet running at a speed decreasing from 100-40kmph impact the engine?
Nope
GTO is offline  
Old 26th March 2009, 08:53   #294
Newbie
 
Join Date: Mar 2009
Location: Banaglore
Posts: 6
Thanked: 0 Times

Quote:
Originally Posted by GTO View Post
Firstly, coasting in neutral at 100 kph is dangerous. Second, look up earlier posts on this thread. There is hardly any fuel saving over slowing down in a gear (which is safer as well).



Nope
Thanks a lot, I always thought it's not safe but also always assumed it's not good for the engine. thanks for clarifying.
romajoshi is offline  
Old 6th April 2009, 05:26   #295
Senior - BHPian
 
VeluM's Avatar
 
Join Date: Jul 2008
Location: Bangalore
Posts: 1,777
Thanked: 1,479 Times

I have a question (not sure if this is the right place, so apologies if it is mis-posted).
Disc brakes are not sprung, so they do not actively disengage from the disc, just sort of don't press any more due to lack of hydraulic pressure. This is true for all cars with discs, I presume.
Has anyone else noticed a lot of black powdery build-up on the front wheel rims and hub-caps due to "carbon deposit" from the brakes?
The reason I ask is that this deposit has to be cleaned frequently at the service centre, else it causes the brakes to bind a bit and hence reduce FE quite a bit.
I haven't noticed anything like this on any of the other cars we (family) have owned (new or old).
PS. The "carbon deposit" thing is the story I was told by the Service Centre people, so I don't know how far that is true either.
VeluM is offline  
Old 6th April 2009, 15:47   #296
BANNED
 
Join Date: Oct 2008
Location: Hyderabad
Posts: 221
Thanked: 12 Times

Velum, that black deposit is called brake dust. check out Brake Dust

I guess 'carbon' is used easily and quickly to describe anything thats black.

personally, I struggle to imagine how fine dust like this can stick and create resistance enough to affect your FE. I may be wrong though.
blacmagic is offline  
Old 6th April 2009, 19:12   #297
Senior - BHPian
 
ImmortalZ's Avatar
 
Join Date: Jan 2008
Location: Trivandrum
Posts: 2,179
Thanked: 488 Times

The fine dust is brake pad residue. This is the material that is shed when you brake. As for the theory that they act like glue, I think its hogwash. Modern disc brakes are self centering and self adjusting. They do stay ever so slightly in touch with the rotors at all times, but this is not because of the dust.

The problem with the brake dust is that it is a chemical cocktail. Without regular cleaning, it may eat into your alloy wheel's finish.
ImmortalZ is offline  
Old 15th April 2009, 00:30   #298
BHPian
 
Join Date: Dec 2008
Location: Hyderabad
Posts: 49
Thanked: 0 Times

What should be the least duration of waiting at a red light to turn off your engine (assuming the traffic light shows the time left to turn it into green)? Does turning it off and on at all stops consume more fuel?
NK@Hyd is offline  
Old 15th April 2009, 08:22   #299
BHPian
 
petrohead's Avatar
 
Join Date: Sep 2008
Location: Bangalore
Posts: 106
Thanked: 0 Times

Quote:
Originally Posted by GTO View Post

Firstly, coasting in neutral at 100 kph is dangerous. Second, look up earlier posts on this thread. There is hardly any fuel saving over slowing down in a gear (which is safer as well).

Nope
Does it affect the braking distance ? ( If when an emergency occurs, Indian roads ain't it! )
petrohead is offline  
Old 15th April 2009, 13:15   #300
GTO
Team-BHP Support
 
GTO's Avatar
 
Join Date: Feb 2004
Location: Bombay
Posts: 70,335
Thanked: 298,731 Times

Quote:
Originally Posted by petrohead View Post
Does it affect the braking distance ? ( If when an emergency occurs, Indian roads ain't it! )
Engine braking can reduce braking distances, while coasting in neutral can make you lose control, especially in an emergency situation.
GTO is offline  
Reply

Most Viewed
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Copyright ©2000 - 2024, Team-BHP.com
Proudly powered by E2E Networks