At 07:39 AM 4/15/98 -0400, you wrote:
>Speaking of oil...I already plan to switch from regular premium oil to
>synthetic due to the severe driving conditions here. What about gasoline?
>I have started to question the relevance of spending the extra money on
>supreme?premium gasoline over regular. Someone once told me it would help
>my engine last longer to use the supreme gasoline. Any thoughts? Was do
>others use for everyday driving?
Nope; here's the situation as I understand it:
People think of high octane gas as being more explosive, having more power,
etc. In reality, it is the opposite. The higher the octane, the *harder*
it is to ignite it!! Basically the only reason to use a higher octane is
if you are getting pinging. What happens is that the engine is very hot,
and there are some places in the engine that are hotter than others. ("hot
spots") When the fuel hits these spots, they are sometimes hot enough to
actually ignite the fuel (instead of having the spark plug ignite the fuel)
This causes the cylender to fire before it is supposed to, which sucks power
and can hurt the engine. If this is happening, the easiest cure is to
use a higher octane fuel. These hot spots are still there, but the
higher octane fuel is harder to ignite, so it won't go off until the spark
plug fires.
Therefore, if you aren't getting any pinging with 87 octane, buying
a higher octane fuel is just wasted money. I have to use 92-93 octane
in my Dak now because I have the MP computer which advances the timing,
but prior to the computer, I ran 87 octane. Due to the way they
reformulate the gas in the winter, I had to use 89 octane in the
winter. (because I was getting pinging with the 87)
-Jon-
.--- stei0302@cs.fredonia.edu -- http://www.cs.fredonia.edu/~stei0302/ ---.
| DoD# 1038, EAA# 518210, NMA# 117376, USUA# A46209, KotWitDoDFAQ, RP-SEL |
| '96 Dodge Dakota v8 SLT Club Cab, '96 Kolb FireFly 447 (#FF019) |
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I do not speak for the SUNY College at Fredonia; any opinions are my own.
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