"miles" wrote in message news:RjXpe.2274$xr.1229@fed1read05...
What's the matter Miles? Are you still upset? Perhaps you should do a little research before jumping in and making an ass out of yourself. Perhaps if you knew anything about how an engine actually runs and how modern emissions systems actually work you would not be so quick to jump in and attack.
Pretty much, but like I said, if you knew half as much as you think you do, you would see the possibility. To further reduce emissions for areas like California where they are very strict, tighter tolerances are required. Then when you add the exceptionally high cost of fuel, especially premium, it is easy to make the assumption that if a vehicle is not to be used for high performance applications, the engine could and would be designed around the characteristics of regular unleaded. This could include things like fuel delivery rates, valve timing, ignition timing, computer curves based on the fuels rate of burn and anti-knock capabilities .... get the picture yet?????
If the fuel burns slower than the engine and its control computers curves were designed for, the O2 sensor is going to detect a false rich run condition because some of that fuel is going to enter the exhaust unburned. I would think that even you could understand this much. Now unless your engine has variable valve timing, there are really only two ways to deal with this situation, increase the timing and/or cut back the fuel. I would hope that even you could understand this much.
Now, since the fuel curves are based on the properties of regular unleaded AND set up for minimum emissions while giving maximum available power, I think that it would be fairly easy to assume that the timing would always be at or near its maximum setting for any given speed and load. That would leave the computer with the simple choice of reducing the injector pulse width (cutting back the fuel amount) to correct what it sees as a rich condition. The problem is that by doing this, what it has actually done is cause a lean run condition.
I guess that you don't know this but unlike a diesel, a gas engine requires a very specific air / fuel ration to run properly. If you run it lean, it will increase cylinder temps and reduce power. I have read posts in here where people noticed power loss when running high octane fuel in engines where the manufacturer stated not to use it. Why do you think that is "all knowing one"? This lean run condition also makes the fuel charge unstable and combined with the added heat, there is the increased possibility of detonation and pre-ignition, both of which can cause damage to the engine, hence, the manufacturers claims of "possible engine damage". Here is a link explaining detonation and pre-ignition.
Yep, so I suggest that you either get started or mind your own business. The sad thing is Miles that you do seem to be a bright guy and we could have some interesting conversations if you didn't resort to turning everything into some sort of personal attack. I'll admit that I was just as bad at one time but I have stopped doing that a while ago. Perhaps if or when you realize that it simply isn't worth the trouble doing that we can get into some interesting discussions and or debates...