89 octane ok?
Safety Car
Joined: Jan 2004
Posts: 3,783
Likes: 15
From: Northern California
Yes, 89 octane can be used but, the ECM will retard the timing to prevent engine knock resulting in reduced engine power.
It's stated in the owners manual.
.
It's stated in the owners manual.
.
Last edited by GKK; Jun 26, 2014 at 01:32 PM.
Drifting
Joined: Oct 2001
Posts: 1,770
Likes: 33
From: Cohasset MN
2017 Corvette of the Year Finalist
2016 C1 of Year Finalist
Check your owner's manual. It will probably say that 89 octane with no more than 10% ethanol is OK. However, I am able to buy 92 octane with no ethanol and I know that my '86 coupe runs better on it. My mileage is also a little better and the acceleration difference is noticeable.
Others on this forum say they experience no difference.
Others on this forum say they experience no difference.
Team Owner
Joined: May 2000
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From: Plantation Florida USAF(Retired) 1966-1990
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St. Jude Donor '05 thru '26
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I used 89 octane ever since I bought mine back in 1991.
Also read the manual it will tell you, that's what you run.
Also read the manual it will tell you, that's what you run.
Instructor
Joined: Dec 2013
Posts: 100
Likes: 20
From: Port St Lucie Florida
You will have to scan the car with tuner pro to know for sure. Look for knock counts and timing retard.
My bone stock '89 will register plenty of knock counts (under heavy acceleration) with anything less then premium fuel.
My bone stock '89 will register plenty of knock counts (under heavy acceleration) with anything less then premium fuel.
Le Mans Master
Joined: Aug 2007
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From: WV
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Melting Slicks
Joined: May 2010
Posts: 2,082
Likes: 3
From: Conowingo Maryland
Mines says the same thing, It says anythingless will spark knock causing the ecm to retard the timing causing less performance
Safety Car
Joined: Aug 2009
Posts: 3,752
Likes: 276
From: Melbourne, Victoria, Australia
, turbo/supercharged engines need premium fuel. factory supercharged/ turbocharged vehicles have that in the handbook.It all depends on the boost you are running, my supercharged/ intercooled vette will ping(knock its head of on standard unleaded . I use the 98 octane stuff that is the only fuel that i have no pinging issues with.
If you are using water/methanol injection that will be different as that will help lower combustion temperatures, that is usually used on blowers without intercoollers.
If using low octane fuel listen out for pinging /knocking, i have gotten away with it on the highway where you just touch the accelerator pedal. just take it easy till your next fill.
Safety Car
Joined: Aug 2013
Posts: 4,430
Likes: 609
From: Minneapolis Mn
Octane
I don't see where the year and engine were listed. When in doubt, use whatever is listed in the owners manual. I have a 86 L98 and it has 9.5-1 compression and it runs just fine on 87 octane gasohol. I do have access to 89 octane 100% gas which I use prior to putting my vehicles away for the winter, but it does run about $1.00 a gallon more than gasohol.
Drifting
Joined: Dec 2011
Posts: 1,439
Likes: 23
From: mesa az
Not to high jack this thread but I have a question regarding gas since it is being discussed. At the time of my engine build I asked the builder what about bumping the compression up to 10.5 ? He urged me to just stay at 9.5 and save my money buying 87 octane. My engine runs fine on the cheaper gas. Is there any advatage for 9.5 compression engines to burn 91 or higher gasoline ? I do on occasion thinking it will clean away any unwanted deposits. I see 91 octane selling for $3.80 a gallon so I am saving a few dollars every time I buy 87 octane gas.
Thread Starter
Racer
Joined: Jun 2014
Posts: 332
Likes: 1
honestly i have run 89 octane in everything i have owned and i have never had a problem with any of them. 2008 hayabusa, 2011 hayabusa, 2002 hayabusa, 2012 gmc sierra, 2011 impala, 2012 impala, 1999 porche 911, hell everything gets 89 which has 10% ethanol blend.
For daily driving i would think the ethanol will be fine. If and when i run it on the track i will most surely fill with bp 92 octane.
For daily driving i would think the ethanol will be fine. If and when i run it on the track i will most surely fill with bp 92 octane.
Le Mans Master
Joined: Oct 2004
Posts: 6,314
Likes: 508
From: South-central Missouri
Put another way: the chances for breaking the motor is significantly higher because of the blower in the best of circumstances. If you have to use the lower octane stuff in a pinch, is one thing. But, why increase the possibility?