Oil Grade Question - Star Motorcycle Forums: Star Raider, V-Max, V-Star, Road-Star Forum
 
LinkBack Thread Tools Display Modes
post #1 of 8 (permalink) Old 02-03-2011, 12:13 PM Thread Starter
Member
 
Gator_Wood's Avatar
 
Join Date: Jan 2011
Location: Central Florida
Posts: 83
Oil Grade Question

When I first got my 1100classic, I was going by the common wisdom of filling it with 91 unleaded on the advice of a couple of people, not thinking about it much. However I recently read on PCS that the stock engine works best with 87. Is this the case, and what difference does it really make? And is it a problem to mix fuel grades in the tank?

2007 V-Star 1100 Classic
Bagger
K&N
OEM Crash Bars
Silverado Windshield

www.DannyGray.com
Gator_Wood is offline  
Sponsored Links
Advertisement
 
post #2 of 8 (permalink) Old 02-03-2011, 03:38 PM
Member
 
Join Date: Aug 2010
Posts: 67
octane in pump gas only determines how easily the fuel reaches combustion, it has nothing to do with how much energy it produces or how efficient the fuel is when it burns.

Generally an engine develops the most horsepower using the lowest octane fuel that will not cause detonation. Unless you have made changes to the engine (other than intake and exhaust) you should go with what the owners manual says.

Mixing doesn't hurt anything provided the mix doesn't make the overall octane too low for the engine. So it can only be an issue on engines that require higher octane.
hig4s is offline  
post #3 of 8 (permalink) Old 02-03-2011, 04:36 PM
Senior Member
 
Fulltilt1's Avatar
 
Join Date: Feb 2010
Posts: 1,530
+1 on the answer and I would add. At 8.3:1 the compression in not high enough ping and or detonate with 87 Octane. At 10.6:1 as with the PCS High Compression Pistons you'd need 91 Octane and with SS Customs 11.1:1 HCPs you'd need 93 Octane. Due in both cases increased above 185psi or more cylinder pressure.

GW
2005 1100 Custom
Speedster Slashdowns
ORKed 5/16" Lines
PODs K&N RU-600s W/PCV
PCS XXX/2 cams
Jetted & PMS Tweaked 20.0/152.5 3.0 turns
AIS Removed/Plugged
Wimmer Machine Custom Oil Cooler & Stash Tube
Pro-1 Tach
Dyna 3000 Step 5/ 6500 redline
TPS Connected
6" Fwd Control Extension W/Boards F&R
Memphis Shades Bullet Fairing
Progressive 465 rear
Progressive Springs and GVE front

10,000 Monkeys throwing crap at the glass and this one thinks he's Picasso...
Fulltilt1 is offline  
Sponsored Links
Advertisement
 
post #4 of 8 (permalink) Old 02-03-2011, 04:37 PM
Senior Member
 
farmalldanzil's Avatar
 
Join Date: Nov 2009
Location: EL Reno OK
Posts: 2,904
Garage
Thumbs up >>>------->

Now that's right on the mark. Two thumbs up
farmalldanzil is offline  
post #5 of 8 (permalink) Old 02-04-2011, 05:33 AM
Member
 
MacVstar1100's Avatar
 
Join Date: Jan 2011
Location: Jonquiere, QC CND
Posts: 84
Thumbs up

Dead on...The only drawback to use higher octane than you need is paying more at the pump...with no benifit

MacVstar1100 is offline  
post #6 of 8 (permalink) Old 02-04-2011, 07:22 PM
Senior Member
 
roxtar's Avatar
 
Join Date: Apr 2009
Location: Eau Claire, WI
Posts: 305
This is unreal! I can't believe there is not one comment about how the higher (priced) octane fuel will give you 20% more power and gains of at least 10 mpg!

Right on, all! Use what the manual says, and use the money you save from buying the un-needed high octane fuel on more important stuff. Like chrome!

2007 Vstar 1300 Tourer
Too many bolt-on goodies to remember!

Gone but not forgotten...

Memeber of the Black Bike Club -- Fastest Color Available!!
roxtar is offline  
post #7 of 8 (permalink) Old 02-04-2011, 08:11 PM
Senior Member
 
linerdave's Avatar
 
Join Date: Sep 2009
Location: N. E. Ohio
Posts: 1,531
Fuel

The 1100 has an 8,3 to 1 compression ratio. does not have an oxygen sensor and fuel injestion. It cannot make changes to alow for higher octane gas.

You may well see a differance on a 1300 with its 9.5 to 1 and electronic fuel control.

Dave
linerdave is offline  
post #8 of 8 (permalink) Old 02-04-2011, 08:35 PM
Senior Member
 
Fulltilt1's Avatar
 
Join Date: Feb 2010
Posts: 1,530
Allow for Higher octane? The 950 is to use 87 octane per manual, same for the 1100. It's the other way around. Higher octane is just a waste of money. If you had higher compression your engine computer might be able to retard the timing to use lower octane fuel. Depending of course on programming limits. Your computer can't raise the compression of your engine. Your compression ratio determines the octane needed. Most high compression engines really don't like the "discount" stuff. LOL

GW
2005 1100 Custom
Speedster Slashdowns
ORKed 5/16" Lines
PODs K&N RU-600s W/PCV
PCS XXX/2 cams
Jetted & PMS Tweaked 20.0/152.5 3.0 turns
AIS Removed/Plugged
Wimmer Machine Custom Oil Cooler & Stash Tube
Pro-1 Tach
Dyna 3000 Step 5/ 6500 redline
TPS Connected
6" Fwd Control Extension W/Boards F&R
Memphis Shades Bullet Fairing
Progressive 465 rear
Progressive Springs and GVE front

10,000 Monkeys throwing crap at the glass and this one thinks he's Picasso...

Last edited by Fulltilt1; 02-04-2011 at 08:53 PM.
Fulltilt1 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Star Motorcycle Forums: Star Raider, V-Max, V-Star, Road-Star Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










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