Premium Vs Regular

[kbrighton]

Re: Premium Vs Regular

Beats me.......... but since you really do still have to wonder if there aren't situations where pre-ignition you can't hear and the computer can't compensate for may still be happening anyway?

Actually, pre-ignition and detonation are two different things. It's detonation that is caused by too low an octane rating, and is a violent explosion of the combustion mixture, rather than a steady burn. The computer can compensate for detonation.
Pre-ignition is caused by things like combustion chamber deposits, and is characterized by the mixture igniting at the wrong time.

For everything you wanted to know about gasoline, check this FAQ:
http://www.faqs.org/faqs/autos/gasoline-faq/part1

[Will]

Re: Premium Vs Regular

Actually, these are the kinds of threads that I find most useful, informative, etc. & they are the ones I always stop to read, possibly even taking notes. Meaning: threads of a technical or mechanical nature. I don't do much for/with my Retro besides put gas (aha!) in it & change the oil. Due to other threads of this techy type I've put in LED & chrome bulbs, upgraded my stereo speakers & --the most important of all -- snapped in a chrome hood scoop bezel. If we didn't have these discussions I wouldn't be able to "play" with my Retro, nor would I even have a clue that these things are possible (or necessary, in the case of the bezel). So I'll disagree, in an agreeable manner, with those who seem to say it's time to pull the plug on this discussion. If you post it, I'll read it. Special thanks to LoneStar, Bronzebird, &
GoBird, whom I find to be consistently & generously helpful with tech info & even with photos. Discussions about bunnies & Moon Pies are all in good fun, & they lend a flavor of sport & friendship to TBN, which gives me a smile, but if that were all that were offered on this site, I would likely not find TBN as valuable & as interesting as I do. So keep posting this kind of stuff ad infinitum -- my Retro likes oil & loves gas. Until the next Apocalypse ... I'm Will

[E'sBird]

Re: Premium Vs Regular

Don't forget, octane rating is altitude sensitive. 90 octane at 8,000 feet is the same as 92 at 500. Lots of factors to consider. Still, overall this is a good thread.

[MerlotBlue]

Re: Premium Vs Regular

Actually, pre-ignition and detonation are two different things. It's detonation that is caused by too low an octane rating, and is a violent explosion of the combustion mixture, rather than a steady burn. The computer can compensate for detonation.
Pre-ignition is caused by things like combustion chamber deposits, and is characterized by the mixture igniting at the wrong time.

For everything you wanted to know about gasoline, check this FAQ:
http://www.faqs.org/faqs/autos/gasoline-faq/part1

You are correct and I was too far liberal with my interchangeable use of the terms.

I simply should have stuck with "detonation" alone.

My bad!

I've edited out "pre-ignition" and replaced it with "detonation"............ thanks for the "heads up".

This topic just keeps coming up around here and the last thing I want to do is add to the confusion.

Ultimately my own "confusion of terms" is seeping into this one as I actually tend to look at detornation as a form of "pre-ignition".....due to the lack of a controlled, slower burn that happens when too low an octane is used. The detonation we all refer to as "ping" on acceleration is the sound of pistons taking a beating as the fuel burns to quickly and unevenly in the environment of extra compression.

Still, it's not the same an I appologize for muddying up the water on this one.

[Phillip]

Re: Premium Vs Regular

Now that we are in the late spring months, and so the petrol does not contain 10% ethanol, I am getting very, very good mileage. On mostly highway driving, my last tank of petrol averaged 25 miles per gallon, which is about 4 miles per gallon better than I have ever gotten in the past.

Strange!

[Rondor]

Re: Premium Vs Regular

Cars has been one of my hobbies for over 50 years, and the biggest thing I have learned is how to determine who knows where-of they speak and who don't. This site fortunately has some pretty qualified opinions and a lot of other good guys who enjoy their cars but know very little. What's nice is most of them know they don't. I know very little about todays cars and will keep it that way since I know many who do know. I am now in the drive and enjoy group. And t-birder's sre the best