Originally Posted by Buzz38
I see a lot of talk about octane being about the burn. It'* about the ignition of the fuel as well. Low octane fuel lights off sooner then higher octane. That'* why they want it (high octane) run in sc motors. Higher compression leads to higher heat which leads to pre-ignition with low octane fuel. You go right ahead and tell these cash strapped college kids to save a few pennies at the expense of their engine if you want to. If there that strapped then maybe they should be driving something different. On the other hand, what is more likely to blow their motor? 87 or 91? If your seeing some pre-ignition with 91 then doesn't it make sense that you'll see a lot more with 87? How much of it can the engine take? That'* what your risking. None of this makes any sense anyway. Why buy a car that recommends premium and then run regular? Just buy a car that recommends regular. You have to pay to play. How much have you got?
Jesus this is really sad. I feel like I should respond to this comment in a nice manner, and normally I would, but when you don't even take the time to figure out the difference between pre-ignition and detonation how can I take anything else you say seriously? I mean hell I explained it in this post! I will say though, I've explained a number of times how this will NOT blow your motor. What do you think a knock sensor is for?
Ponder this for a second. One person said the PCM can retard the ignition 15deg. I'm assuming this means -15 as anytime the PCM pulls timing its considered retarding. So with premium you run about 24deg advance at idle. You're telling me that pulling 39deg of timing won't compensate for 87 octane?? Ok but what about WOT? I run about 10-11deg of advance at WOT on 92octane. Take 25-26deg of timing away and you still don't think it can compensate?? Think about that some.
Originally Posted by jr's3800
Bill I agree... If the car reccomends Premium Fuel ( 91 or better ) than use 91 or better.... This is why I have 2 bonneville that will both run off of 87.... I did a little test of sorts.... I drove on 87 for 2 tank fulls and did ok.... I ran 89 and had a bit more power to boot, not much but it was noticeable.... I did 29 MPG pulling the mountains, and running 80-100 mph and I had many foot stomps to the floor while pulling through the mountains, car loaded down, AC on all the way.... And I still managed 29 Mpg.... I'd say thats not too bad.... But If I had an SC'd 3800, you can bet it will get 91 or better.... I just wouldn't be able to live without the performance..
You've said nothing to counter the debate. NOBODY said you won't lose performance. Matter a fact I said several times you WILL lose performance but thats not what we're talking about.
It gets a little frustrating to sit here and read peoples, sometimes cocky, responses about how they lost performance or how "well the label says" or a whole host of other opinions that have nothing to do with what the debate is about or flat out hold no water.
Look if I'm wrong I'm wrong and I'll admit it. But I won't admit it because you tell me about how much better fuel economy you get, what the label says (although aparently the manual says you can use it), or because you think you need to "pay to play." Find an expert or someone mutually agreed upon as an expert that says you will damage your engine running lower octane WITH A KNOCK SENSOR and we can go from there.
OBVIOUSLY this is something that needs discussed because I can (and have) pointed to several 'expert' sources to counter the other side of the debate but all I can get in return is myth after myth....Hey what ever happened to premium being a "cleaner" fuel?? How about oxygenated fuel being "more powerful"??