50 - 54 Mpg at 30mpg at 1000 Rpm? - Chevy Cobalt Forum / Cobalt Reviews / Cobalt SS / Cobalt Parts
All about MPG All about maximizing your Miles Per Gallon (MPG)

Closed Thread
 
LinkBack Thread Tools Display Modes
post #1 of 28 (permalink) Old 03-23-2010, 11:47 PM Thread Starter
Contributor
 
Join Date: Nov 2009
Posts: 489
50 - 54 Mpg at 30mpg at 1000 Rpm?

YouTube - SSPX0099.3g2

YouTube - SSPX0098.3g2

Now my main question is how bad is it for then engine, clutch ect, to be running at 1000 rpm at 30 mph while in 5th?
darklide is offline  
Sponsored Links
Advertisement
 
post #2 of 28 (permalink) Old 03-23-2010, 11:56 PM
XFE
Wootsauce!
Staff Alumni
YourCobalt.com Premium Member


 
Join Date: Oct 2008
Location: Pittsburgh, PA
Posts: 8,593
Send a message via AIM to XFE
my question is...why are you in 5th gear @ 30 mph????




XFE is offline  
post #3 of 28 (permalink) Old 03-24-2010, 12:20 AM Thread Starter
Contributor
 
Join Date: Nov 2009
Posts: 489
Quote:
Originally Posted by Cobaltxfe09 View Post
my question is...why are you in 5th gear @ 30 mph????
Good question, to achieve the best mpg possible, but I'm guessing it's not good for the car at all.
darklide is offline  
 
post #4 of 28 (permalink) Old 03-24-2010, 01:49 AM
Not justice...Punishment
Staff Alumni
YourCobalt.com Premium Member


 
Will mpg's Avatar
 
Join Date: Sep 2009
Location: Brownsville, TN U.S.A.
Posts: 3,829
Garage
I don't see anything wrong with it so long as you are only trying to maintain the speed you are going. Using tallest possible gearing with lowest possible rpm is what good mpg is all about. It's also the theory used in building the new vettes, and why their mpg hwy is up to around 30.

The catch is you should NEVER try speeding up with the car in 5th going this slow. It "lugs" the motor, and is hard on just about every internal part of the motor.

Personally I would suggest not being in 5th gear below 35 mph.

Will mpg is offline  
post #5 of 28 (permalink) Old 03-24-2010, 02:01 AM
Contributor
 
Join Date: Oct 2009
Location: Conneaut, Ohio
Posts: 273
False! at such a low RPM in a high gear WILL REQUIRE the engine to work HARDER and therefore burn more gas. if your in a high gear at a low speed, you hear the engine gets bogged down. this is why some V8s get better MPG than some V6s.


2006 Chevy Cobalt 2LT Coupe - Majestic Amethyst Metallic - Auto Trans
Factory- power windows, power locks, keyless entry, sunroof, chrome exhaust tip, leather steering wheel, leather shifter, white face gauges, fogs, and spoiler
Showoff Thread
Scribs is offline  
post #6 of 28 (permalink) Old 03-24-2010, 03:08 AM
Not justice...Punishment
Staff Alumni
YourCobalt.com Premium Member


 
Will mpg's Avatar
 
Join Date: Sep 2009
Location: Brownsville, TN U.S.A.
Posts: 3,829
Garage
^^^ Wow Scribs. Right or wrong at least you have a lot of passion on the subject. I will agree....... to disagree.

darklide- I recommend that you make up your own mind by trying different techniques and keeping track of your mpg. This information will tell you the best thing to do to max your mpg. Honestly it's hard to judge what will work for you. It will depend on your particular driving conditions, habits, your car, etc. A person who lives in a flat part of the country would have a lot better luck with this approach than someone who has a lot of hills to contend with on a daily basis.

Will mpg is offline  
post #7 of 28 (permalink) Old 03-24-2010, 09:18 AM
Contributor
 
Join Date: Oct 2009
Location: Conneaut, Ohio
Posts: 273
Quote:
Originally Posted by Will mpg View Post
^^^ Wow Scribs. Right or wrong at least you have a lot of passion on the subject. I will agree....... to disagree.

darklide- I recommend that you make up your own mind by trying different techniques and keeping track of your mpg. This information will tell you the best thing to do to max your mpg. Honestly it's hard to judge what will work for you. It will depend on your particular driving conditions, habits, your car, etc. A person who lives in a flat part of the country would have a lot better luck with this approach than someone who has a lot of hills to contend with on a daily basis.
Well, when I had my '93 Ford Probe with the V6 it had 165K miles and I drove 100 miles a day just to and from work. I got 32 MPG in it without doing any mods or even a tune up. I have had to deal a lot with this issue when I worked in maint for a vending company (of all places) because we put many miles on the trucks everyday and saving a few gallons of gas added up a lot by the end of the week. I know about power vs MPG and the size of the engine and gearing making a difference. But one thing is always true, the LESS load on the engine without over revving, is what makes best MPG. Low RPM in high gear is a high load and high RPM in gear is less load but uses a lot of fuel to run at high RPM. Why do you think its a must to down shift a truck when going up hill? It has nothing to do with MPG, its the engine load.


2006 Chevy Cobalt 2LT Coupe - Majestic Amethyst Metallic - Auto Trans
Factory- power windows, power locks, keyless entry, sunroof, chrome exhaust tip, leather steering wheel, leather shifter, white face gauges, fogs, and spoiler
Showoff Thread
Scribs is offline  
post #8 of 28 (permalink) Old 03-24-2010, 09:02 PM
Forum Regular
 
Fr3AkAzOiD's Avatar
 
Join Date: Sep 2009
Location: Raleigh, NC
Posts: 219
My opinion, if you are stuck doing 30 mph, do small pulse and glides in fourth.

Accelerate to 35 in fourth throttle wide open and then do a neutral glide down to like 28 mph.

I never use 5th gear below 40mph, unless maybe if it's on a slight downhill.

If you driving situation has you stuck at 30 mph I would keep it in fourth.

Fr3AkAzOiD is offline  
post #9 of 28 (permalink) Old 03-24-2010, 09:46 PM
Forum God


 
BboyTaktix's Avatar
 
Join Date: Oct 2009
Location: CANADA! Montreal (party city), Quebec
Posts: 3,229
Quote:
Originally Posted by Fr3AkAzOiD View Post
My opinion, if you are stuck doing 30 mph, do small pulse and glides in fourth.

Accelerate to 35 in fourth throttle wide open and then do a neutral glide down to like 28 mph.

I never use 5th gear below 40mph, unless maybe if it's on a slight downhill.

If you driving situation has you stuck at 30 mph I would keep it in fourth.
no that's worse. best thing for mpg, whatever gear you are in, is to stay at constant speed. if you keep slowing down and speeding up, the engine has to keep working to increase inertia of the car to a higher speed. and i would not go to 5th at 30mph either, it's a bit low and i do believe it would wear on the engine more.
BboyTaktix is offline  
post #10 of 28 (permalink) Old 03-24-2010, 11:06 PM Thread Starter
Contributor
 
Join Date: Nov 2009
Posts: 489
Quote:
Originally Posted by BboyTaktix View Post
no that's worse. best thing for mpg, whatever gear you are in, is to stay at constant speed. if you keep slowing down and speeding up, the engine has to keep working to increase inertia of the car to a higher speed. and i would not go to 5th at 30mph either, it's a bit low and i do believe it would wear on the engine more.
What about at 40 mph.
darklide is offline  
Sponsored Links
Advertisement
 
Closed Thread

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



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
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome