Is premium gas necessary for a supercharged 3.8?
10-30-2007, 06:56 PM
#1
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Is premium gas necessary for a supercharged 3.8?
Just wondering. Perhaps mid-grade is ok?
Sorry if this question is asked all the time
Sorry if this question is asked all the time
10-30-2007, 07:04 PM
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yes, to keep form getting KR (knock Retard) you must run at least 91
The way i look at it, its only like another 2-3$ per fill up to run 93. so why not
The way i look at it, its only like another 2-3$ per fill up to run 93. so why not
10-30-2007, 07:05 PM
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10-30-2007, 07:14 PM
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There are 2 timing tables in the 96+ PCMs, one is designed for "bad gas" aka 85 or 87 octane.
On a stock car you can get away with it but if you are modded, dont even think about it.
On a stock car you can get away with it but if you are modded, dont even think about it.
10-30-2007, 10:05 PM
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When KR is seen by the PCM, the knock has aleady happened.
It'* like scolding your dog to stop him from barking. The neighbors are still pissed.
In the case of KR, the damage happens slowly in small increments BEFORE the sensors and PCM see it. The bottom line is that if you are in a financial situation where you can't afford 91 or higher octane, you're better off selling the car. You will get more timing and higher mileage with the proper octane than you will with lesser octane, and you won't slowly kill your engine.
It'* like scolding your dog to stop him from barking. The neighbors are still pissed.
In the case of KR, the damage happens slowly in small increments BEFORE the sensors and PCM see it. The bottom line is that if you are in a financial situation where you can't afford 91 or higher octane, you're better off selling the car. You will get more timing and higher mileage with the proper octane than you will with lesser octane, and you won't slowly kill your engine.
10-31-2007, 06:03 PM
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If your close to stock as stated earlier the newer PCMs have 2 fuel tables. And there is a HUGE difference. I used to run 89 in my car thru the winter (it kept the car slow-er), granted it was cold so I was quite a bit safer. So for a temporary fix your fine, to do it permanently your slowly killing your car-very slowly! Just don't be a lead foot with low oct!
You can tell a huge difference in S2 L67'* that have been ran on low oct. most of their lives vs. one that has had higher oct. Go to the dealership and test drive one you'll see what I'm talking about.
You can tell a huge difference in S2 L67'* that have been ran on low oct. most of their lives vs. one that has had higher oct. Go to the dealership and test drive one you'll see what I'm talking about.
10-31-2007, 11:33 PM
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Perhaps I need to dumb it down again, lets assume for a second and take modifications out of the equation.
ANY vehicle that has high compression, or bolted on power adders like a supercharger or turbocharger will require high octane fuel to avoid pre-detonation. If you choose not to use at least 91 gas, the PCM will retard timing and you will experience poorer fuel economy and loss of performance.
You're car will still work, but its not worth the $$
Add in some mods that boost performance and you'd be a fool not to use the proper fuel.
ANY vehicle that has high compression, or bolted on power adders like a supercharger or turbocharger will require high octane fuel to avoid pre-detonation. If you choose not to use at least 91 gas, the PCM will retard timing and you will experience poorer fuel economy and loss of performance.
You're car will still work, but its not worth the $$
Add in some mods that boost performance and you'd be a fool not to use the proper fuel.
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