Regular (87 Octane) Gas in WRX?
Registered User
Joined: Apr 2003
Posts: 257
From: Arcadia, CA
Car Info: 2003 GGA
My understanding of the situation is this...
Because the turbo is putting a greater charge in the cylinder there is a greater chance the charge will predetonate, aka ping. Predetonation is bad because it is applying the force of detonation at the wrong time (while the engine is trying to compress the charge) and WILL damage your engine. I'm not learned enough to know whether or not the ECU will intervene. Perhaps some others here can speak to that. I'd be interested to know.
Because the turbo is putting a greater charge in the cylinder there is a greater chance the charge will predetonate, aka ping. Predetonation is bad because it is applying the force of detonation at the wrong time (while the engine is trying to compress the charge) and WILL damage your engine. I'm not learned enough to know whether or not the ECU will intervene. Perhaps some others here can speak to that. I'd be interested to know.
Registered User
Joined: Apr 2003
Posts: 257
From: Arcadia, CA
Car Info: 2003 GGA
to finish my thought...
the higher octane gas is less subject to predetonation because the fuel molecules are more "branched" i.e. less linear in structure and thus more stable. The reason higher octane gas provides more power is because the fuel burns more "at once" providing a more concentrated effort/impulse, if you will.
Please feel free to correct me...this is just how I understand the whole mess.
the higher octane gas is less subject to predetonation because the fuel molecules are more "branched" i.e. less linear in structure and thus more stable. The reason higher octane gas provides more power is because the fuel burns more "at once" providing a more concentrated effort/impulse, if you will.
Please feel free to correct me...this is just how I understand the whole mess.
Registered User
Joined: Apr 2003
Posts: 492
From: Rockville, MD
Car Info: 2003 Silver WRX Sedan, 1982 Corvette Collectors Ed.
Omg here's a new one.
Ride The Bus!
No really, ride the bus. You help cover my paycheck!
And its cheap, and its as fast, and its entertaining, and.....
Ride The Bus!
No really, ride the bus. You help cover my paycheck!
And its cheap, and its as fast, and its entertaining, and.....
Guest
Posts: n/a
Fellas, Clint is right. About detonation that is. "Branched fuel molecules" are a little over my head but with the added charge the fuel can definitely pre-detonate. 'Not sure about how the ECU handles this. I would think that there would be some sort of detonation sensor there to retard timing but I'm really not sure. Anyone heard of this or am I way out in left field?
Check out the book "Turbochargers" by Hugh MacInnes (HPBooks 1984, ISBN 0-89586-135-6). It deals mostly with carbuereted vehicles but it's got a lot of real good info.
Check out the book "Turbochargers" by Hugh MacInnes (HPBooks 1984, ISBN 0-89586-135-6). It deals mostly with carbuereted vehicles but it's got a lot of real good info.
Guest
Posts: n/a
Originally posted by RCFerrara
I would think that there would be some sort of detonation sensor there to retard timing but I'm really not sure. Anyone heard of this or am I way out in left field?
I would think that there would be some sort of detonation sensor there to retard timing but I'm really not sure. Anyone heard of this or am I way out in left field?
Guest
Posts: n/a
Race gas locations
The link is a site that gives you all the locations for Sunoco GT100 in your area.
The only time you can skimp using cheap gas is in the winter. The colder air has more O2 so you can use the MID GRADE stuff 88-90 octane. This is only when you know the temps will be below freezing. I do this in the winter and never have issues. But if it's above freezing I put 94 in.
The link is a site that gives you all the locations for Sunoco GT100 in your area.
The only time you can skimp using cheap gas is in the winter. The colder air has more O2 so you can use the MID GRADE stuff 88-90 octane. This is only when you know the temps will be below freezing. I do this in the winter and never have issues. But if it's above freezing I put 94 in.
Registered User
Joined: Nov 2002
Posts: 261
From: So. Ca., CA USA
Car Info: 03 WRX / 08 Forester
Originally posted by vteg
Cali is not in the list. Stop teasing us
Cali is not in the list. Stop teasing us
Registered User
Joined: Aug 2022
Posts: 1
From: Kentucky
Car Info: 2004 Subaru WRX Wagon
This aged well.
This aged well.
So, the manual says something like use premium gas only, but it's OK to use lesser grades from time to time.
Some people say the requirement to use higher grade is bogus, but I don't know.
But I do know that premium gas is like 2.40 on average per gallon in so. Cal. and it takes between $30-35 to fill the tank.
Like most of you all, I love my wrx, but these prices are killing me.
Is the high grade really a must-have? Or could I get regular gas and add octane boost? Does it really matter?
Any serious answers are much appreciated.
Some people say the requirement to use higher grade is bogus, but I don't know.
But I do know that premium gas is like 2.40 on average per gallon in so. Cal. and it takes between $30-35 to fill the tank.
Like most of you all, I love my wrx, but these prices are killing me.
Is the high grade really a must-have? Or could I get regular gas and add octane boost? Does it really matter?
Any serious answers are much appreciated.
Thread
Thread Starter
Forum
Replies
Last Post
specb
Bay Area
17
Sep 12, 2006 01:56 PM
