Carbs, Fueling, and You! - Chevy Cobalt Forum / Cobalt Reviews / Cobalt SS / Cobalt Parts
Other Cars Talk about cars other than the Chevy Cobalt here

 
LinkBack Thread Tools Display Modes
post #1 of 10 (permalink) Old 07-23-2014, 07:45 AM Thread Starter
Super Moderator


 
Plain Jane's Avatar
 
Join Date: Mar 2013
Location: Montreal, Quebec
Posts: 3,860
Garage
Carbs, Fueling, and You!

Will I see a difference (performance, economy, etc) from using a higher octane fuel (94) in a carb'd and cat'd motor? This is in regards to my old stock Bonneville 3800.

She was rated at 110hp and 190tq from the factory.

---------- Post added at 10:45 AM ---------- Previous post was at 10:40 AM ----------

And is running it hard on occasion beneficial for cleaning out carbon build up?

'07 Eclipse GT build thread - 280whp, 254wtq
Plain Jane is offline  
Sponsored Links
Advertisement
 
post #2 of 10 (permalink) Old 07-23-2014, 07:47 AM
Forum Regular
 
Join Date: Jan 2014
Posts: 163
Theoretically you shouldn't, since the purpose of the higher octane fuel is to prevent knocking from higher compression engines. If your car is designed to run on regular, all the higher octane fuel will do is leave you with a little less money after filling up, I would think. But I'm no mechanic or engineer, so don't take my word as 100% fact.
Justinw303 is offline  
post #3 of 10 (permalink) Old 07-23-2014, 07:54 AM Thread Starter
Super Moderator


 
Plain Jane's Avatar
 
Join Date: Mar 2013
Location: Montreal, Quebec
Posts: 3,860
Garage
I would normally agree, but this car doesn't have the complex computers or tuning of a modern fuel injected car. My thinking is that the engine can immediately take advantage of the higher grade fuel and make more from it than regular 87. No retune or reflash necessary.

That's my best guess however. Good chance I may be barking up the wrong tree.

'07 Eclipse GT build thread - 280whp, 254wtq
Plain Jane is offline  
 
post #4 of 10 (permalink) Old 07-23-2014, 08:05 AM
Staff Alumni
 
money_man's Avatar
 
Join Date: Mar 2012
Location: Halifax, N.S
Posts: 3,127
Its a 100hp car. Run regular and don't waste your money unless you start hearing detonation

2009 Ford Escape Limited - 3.0L, 6 speed auto, 4x4, 25/33 city/hwy imp mpg.
2017 F150 XLT-XTR - 5.0L, 4x4, 3.55's, E-locker, xtr chrome package, fx4 off-road package.
20/25 imp mpg
money_man is offline  
post #5 of 10 (permalink) Old 07-23-2014, 12:32 PM Thread Starter
Super Moderator


 
Plain Jane's Avatar
 
Join Date: Mar 2013
Location: Montreal, Quebec
Posts: 3,860
Garage
Car runs rough. Needs a tune up. I played with the distributer last year without much luck. Good gas may help.

'07 Eclipse GT build thread - 280whp, 254wtq
Plain Jane is offline  
post #6 of 10 (permalink) Old 07-23-2014, 01:34 PM
Super Moderator
YourCobalt.com Premium Member


 
Coby7's Avatar
 
Join Date: Oct 2011
Location: Magnetic Hill, New-Brunswick
Posts: 11,820
Garage
Regular gas actually has more energy in it than higher octane and is cleaner since it has less additives. The car even that old bonneville has spark knock sensors and will set the spark timing just before detonation for best performance. If it runs bad it probably needs new spark plugs or a can of gas treatment.

Every minute spent angry is a happy minute lost for ever and ever!!!
Drives 2016 Cocoa Buick Encore 1.4L Turbo auto KL4CJDSB2GB652675
Drives 2016 Sunset Orange Trax LT1 1.4L Turbo auto 3GNCJPSB8GL142716

Never drive faster than your guardian angel can fly
Coby7 is offline  
post #7 of 10 (permalink) Old 07-23-2014, 02:22 PM Thread Starter
Super Moderator


 
Plain Jane's Avatar
 
Join Date: Mar 2013
Location: Montreal, Quebec
Posts: 3,860
Garage
Thanks Coby. I did check the plugs last year, and even sand blasted them myself, but it could be possible they're past due. I'll find a Bonneville forum and ask around what they think.

'07 Eclipse GT build thread - 280whp, 254wtq
Plain Jane is offline  
post #8 of 10 (permalink) Old 07-24-2014, 04:06 PM
Forum Regular
 
nowachevyowner's Avatar
 
Join Date: Sep 2010
Location: delaware
Posts: 157
The octane rating is the fuel's resistance to spontaneous combustion under compression. The higher the octane rating, the more compression it takes to make the fuel spontaneously ignite. If your car is not high compression you are wasting money. Since higher octane takes more to burn low octane will work better in a Cobalts.
nowachevyowner is offline  
post #9 of 10 (permalink) Old 07-24-2014, 05:28 PM Thread Starter
Super Moderator


 
Plain Jane's Avatar
 
Join Date: Mar 2013
Location: Montreal, Quebec
Posts: 3,860
Garage
Same goes for a carb'd OHV?

'07 Eclipse GT build thread - 280whp, 254wtq
Plain Jane is offline  
post #10 of 10 (permalink) Old 07-24-2014, 05:58 PM
Forum Regular
 
Join Date: Jan 2014
Posts: 163
I would imagine so, since the principles of pre-ignition are the same seeing as the combustion process is essentially the same.
Justinw303 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