Go Back   Tech Support Forum > Automotive Center > Automotive Support

mix of regular and premium gas?

This is a discussion on mix of regular and premium gas? within the Automotive Support forums, part of the Tech Support Forum category. I found that my 2006 Escape runs better without knocking while accelerating by using premium gas. But it costs much


Reply
 
Thread Tools Search this Thread
Old 01-27-2011, 08:56 AM   #1
FAQ
Registered Member
 
Join Date: Mar 2006
Posts: 114
OS: xp



I found that my 2006 Escape runs better without knocking while accelerating by using premium gas. But it costs much more than regular gas. Is it alright to use reg-premium-reg-premium gas alternatively?

__________________
FAQ is offline   Reply With Quote
Old 01-27-2011, 10:03 AM   #2
GIGO
 
Raylo's Avatar
 
Join Date: Feb 2006
Location: Maryland, USA
Posts: 1,423
OS: Win7 x64 (desktop and laptop) and XP Pro laptop



Sure, no problem doing that. But I am surprised that you see a noticeable difference.

__________________
Raylo is offline   Reply With Quote
Old 01-27-2011, 02:12 PM   #3
FAQ
Registered Member
 
Join Date: Mar 2006
Posts: 114
OS: xp



Quote:
Originally Posted by Raylo View Post
Sure, no problem doing that. But I am surprised that you see a noticeable difference.
Yes, it does run better. I searched the web for this knocking while accelerating problem. Switching to premium gas is one of the solutions.
__________________
FAQ is offline   Reply With Quote
Old 01-27-2011, 04:46 PM   #4
Automotive Team
Moderator
 
wolfen1086's Avatar
 
Join Date: Oct 2007
Location: Rainey, Virginia Beach, Virginia
Posts: 10,247
OS: Ubuntu 14.04



Cars that are designed to run on Premium will make a knocking sound when they run on regular, its called spark knock,the works case problem that I know of from this is screwed up plugs. but your gas mileage might suffer too, plus I have never run across the long term spark knock so I have no idea what else it could do to the engine.
__________________

Hampton Roads Virginia, I've been around the rock three times and this place was NOT on my top ten list of places to live
wolfen1086 is offline   Reply With Quote
Old 01-27-2011, 11:40 PM   #5
GIGO
 
Raylo's Avatar
 
Join Date: Feb 2006
Location: Maryland, USA
Posts: 1,423
OS: Win7 x64 (desktop and laptop) and XP Pro laptop



Indeed, and most modern cars have knock sensors and computer spark retard that dials back the timing to avoid detonation at the expense of a little power. But even though I haven't looked it up I doubt an Escape specs premium gas.
__________________
Raylo is offline   Reply With Quote
Old 01-28-2011, 07:24 AM   #6
FAQ
Registered Member
 
Join Date: Mar 2006
Posts: 114
OS: xp



Quote:
Originally Posted by Raylo View Post
Indeed, and most modern cars have knock sensors and computer spark retard that dials back the timing to avoid detonation at the expense of a little power. But even though I haven't looked it up I doubt an Escape specs premium gas.
I remembered when I searched for solutions, it did mention about timing too fast or mixture too rich. The Escape can be pretty peppy when stepping on the gas. Maybe that is the cause of it. Escape only asks for the use of regular gas.
__________________
FAQ is offline   Reply With Quote
Old 01-28-2011, 10:02 AM   #7
GIGO
 
Raylo's Avatar
 
Join Date: Feb 2006
Location: Maryland, USA
Posts: 1,423
OS: Win7 x64 (desktop and laptop) and XP Pro laptop



This is a perennial topic in every auto forum I have ever been a member of. My opinion: if your maintenance is up to date it is very unlikely that you will get sufficiently bad detonation (pinging) on the recommended fuel to cause significant spark retard (and thus hurt performance). Keep in mind that the most efficient programming brings the timing right up to the max for the design and fuel and that is what Ford intends and, I'm sure, supplies. And a motor designed and intended for regular will not benefit in any substantial way from premium gas. But the bottom line is it's your $ and if you think you are getting 20 cets per gallon benefit by running premium, then go for it. Won't hurt anything except your wallet.
__________________
Raylo is offline   Reply With Quote
Old 01-28-2011, 04:12 PM   #8
Automotive Team
Moderator
 
wolfen1086's Avatar
 
Join Date: Oct 2007
Location: Rainey, Virginia Beach, Virginia
Posts: 10,247
OS: Ubuntu 14.04



Maybe its the gas?
well...fuel, it hasn't been gas in a hellofa long time.
__________________

Hampton Roads Virginia, I've been around the rock three times and this place was NOT on my top ten list of places to live
wolfen1086 is offline   Reply With Quote
Old 01-28-2011, 04:28 PM   #9
Team Manager, Gaming
Team Manager, Microsoft Support
Team Manager, Hardware Team
Microsoft MVP
 
Wrench97's Avatar

Microsoft Most Valuable Professional
 
Join Date: May 2008
Location: S.E. Pennsylvania
Posts: 49,264
OS: Win7



Too lean, the timing too far advanced, (but the PCM controls the timing on all OBD II engines,) will cause a spark knock, long term it causes burnt pistons, the knock is from high cylinder temps starting combustion before the shark plug fires, when the plug fire the 2 explosions hit each other and cause the knock.
Wrench97 is offline   Reply With Quote
Old 01-28-2011, 05:27 PM   #10
Automotive Team
Moderator
 
wolfen1086's Avatar
 
Join Date: Oct 2007
Location: Rainey, Virginia Beach, Virginia
Posts: 10,247
OS: Ubuntu 14.04



That makes sense, so spark knock would be a VERY bad thing.
__________________

Hampton Roads Virginia, I've been around the rock three times and this place was NOT on my top ten list of places to live
wolfen1086 is offline   Reply With Quote
Old 01-28-2011, 08:52 PM   #11
FAQ
Registered Member
 
Join Date: Mar 2006
Posts: 114
OS: xp



Quote:
Originally Posted by wolfen1086 View Post
That makes sense, so spark knock would be a VERY bad thing.
Then it's the money well spent because I don't hear the knocking when accelerating. But how does the high octane (only 4 octane difference) premium gas/fuel retard the advanced timing?
__________________
FAQ is offline   Reply With Quote
Old 01-29-2011, 02:20 AM   #12
Team Manager, Gaming
Team Manager, Microsoft Support
Team Manager, Hardware Team
Microsoft MVP
 
Wrench97's Avatar

Microsoft Most Valuable Professional
 
Join Date: May 2008
Location: S.E. Pennsylvania
Posts: 49,264
OS: Win7



It does not the higher the octane the higher the flash point so the fuel does not ignite by the cylinder temp.
It may be worth having it checked out for a vacuum leak or a bad knock sensor, the PCM has what's reffered to as a learning curve, it'll learn over a number of key starts where the timing and fuel settings are so once moving to hi-test the PCM will learn the settings in order to go back to regular it'll have to relearn or you'll have to reset the PCM.
Wrench97 is offline   Reply With Quote
Old 01-29-2011, 05:40 AM   #13
GIGO
 
Raylo's Avatar
 
Join Date: Feb 2006
Location: Maryland, USA
Posts: 1,423
OS: Win7 x64 (desktop and laptop) and XP Pro laptop



I don't think that a car designed for regular will typically be able to advance the timing beyond the stock calibration to take advantage of premium gas. It is usually just the other way around. If the knock sensors see a threshold level of pinging (a little is not bad) the PCM will pull timing back. We run TTS datamaster to check and tune our F body motors and you can see the retard events for a too aggressive PCM program. But there are no "advance" events. There is a programmed spark timing curve based on many input parameters and any PCM action retards from that if it sees beyond threshold knock.

Like Wrench says there is a lot of learning going on as well. Maybe it will learn and adjust how fast it makes retard actions if/when it does get pinging and be more aggressive based on history, which might vary from reg or premium gas? I'm not sure about that, though.

But if your motor and sensors are working correctly, and the gas is in spec, the slight pinging you hear should not be damaging.... unless Ford really screwed up. I don't think they make those kinds of mistakes, and I'm not even a Ford guy!
__________________
Raylo is offline   Reply With Quote
Old 01-29-2011, 06:19 AM   #14
Automotive Team
Moderator
 
wolfen1086's Avatar
 
Join Date: Oct 2007
Location: Rainey, Virginia Beach, Virginia
Posts: 10,247
OS: Ubuntu 14.04



Quote:
Originally Posted by FAQ View Post
Then it's the money well spent because I don't hear the knocking when accelerating. But how does the high octane (only 4 octane difference) premium gas/fuel retard the advanced timing?

Its only money well spend if you can afford it.

__________________

Hampton Roads Virginia, I've been around the rock three times and this place was NOT on my top ten list of places to live
wolfen1086 is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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 Off
Pingbacks are Off
Refbacks are Off


Post a Question


» Site Navigation
 > FAQ
  > 10.0.0.2


All times are GMT -7. The time now is 10:23 PM.


Copyright 2001 - 2014, Tech Support Forum

Windows 7 - Windows XP - Windows Vista - Trojan Removal - Spyware Removal - Virus Removal - Networking - Security - Top Web Hosts