BTW, that said, the Volt's engine (and it's nearly identical cousing in the 1.4L turbo Cruze Eco) made green engine of the year for 2012... it's a very nice plant, smooth and torquey in the low end with the tiny blower in the Cruze.
It's actually not a GM engine in the way Americans think of them.
The 1.4L I4 in the Volt is designed by Opel (Opel Family 0), so it is actually a "European" engine, although under the GM umbrella.
Sadly, GM US doesn't seem to be able to design anything good less than 3 liters. The 1.6L eco engine is also an Opel design.
Sam
It is totally a GM engine. Opel is just a GM division like Chevrolet or Cadillac. They have been wholly owned by GM since 1929. GM is doing the smart thing. They are making the best use of every divisions strengths.
I've been watching both the spark advance the knock sensor retardation and I was SHOCKED at how much the latter was used.
It basically seems like the regular spark advance is the coarse adjustment(0.5 degrees) and the knock sensor retardation is used as the fine adjustment(0.1 degrees). The knock sensor is being used under all but the lightest load conditions.
It was very interesting, and could explain why some people are able to detect a difference between low and high octane fuel - probably signaling that something is wrong with their engine.
I ran 100% gas high octane fuel for 3-4 tanks in two cars and was not able to detect a difference in normal driving.
Quote:
Originally Posted by theaveng
Okay. The Volt's engine has a lower compression than our engine. Why do you think they require 91 then?
Because it has vastly different combustion chamber design. Do you ignore my posts on purpose?
Quote:
I notice my tank runs out of fuel faster (fewer total miles) with E10 because it has less energy.
A gallon of 100% gasoline contains 114,000 BTU. A gallon of E10 contains 112,000 BTU. That's a difference of 1%. Is it possible to detect that? Sure. But you'd better have the exact same 100mpg commute every day, or I'm just simply not going to believe you.
Quote:
Originally Posted by theaveng
That sounds wrong. The charge of fuel is so small the combustion time is near instant & any difference between 87 and 91 "time to burn" is probably not measurable.
Of course it's measurable. Everything that exists is measurable. High octane fuel burns slower than low octane fuel. It also contains less energy than low octane fuel. However, refineries typically try and keep the difference to within 2%.
Wow, I finally got someone to post their observations on the timing which I drive with.
Have you noticed the advance around 3200 rpm.
Look at full throttle around 2K.......PANIC
Willie
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cool vid eli! wonder what the advance was? Im gonna have to check out the advance that willie mentioned-should be interesting to see.
"It was very interesting, and could explain why some people are able to detect a difference between low and high octane fuel - probably signaling that something is wrong with their engine"
Eli, are you saying the people that notice the change might have something wrong with the engine? or, the opposite? (im reading it either way so unsure what you mean).
as for e10 gas. Ive not noticed a perceptible diffrence with that vs 100 gas. Now granted if i hooked up the scanner and data logged it then sure, i might see something-but not feel it. now e85 vs e10, then yes-(but thats a whole new post)
On my Dodge I can normally go 350 miles on a tank, but with E10 I have to stop at 300 else I will be run out. I have observed exactly the same with the Plymouth I used to own. E10 may only be 2% lower than regular gasoline's energy but I see a much bigger difference than that in real use (about 10%).
As for the knock sensor, I would expect it would be used less often with the 91 grade than the 87 grade.
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cool vid eli! wonder what the advance was? Im gonna have to check out the advance that willie mentioned-should be interesting to see.
"It was very interesting, and could explain why some people are able to detect a difference between low and high octane fuel - probably signaling that something is wrong with their engine"
Eli, are you saying the people that notice the change might have something wrong with the engine? or, the opposite? (im reading it either way so unsure what you mean).
as for e10 gas. Ive not noticed a perceptible diffrence with that vs 100 gas. Now granted if i hooked up the scanner and data logged it then sure, i might see something-but not feel it. now e85 vs e10, then yes-(but thats a whole new post)
I'm saying it's likely people who are able to notice a difference with high octane fuel have carbon build up in their combustion chambers, possibly from burning oil.
Quote:
Originally Posted by theaveng
On my Dodge I can normally go 350 miles on a tank, but with E10 I have to stop at 300 else I will be run out. I have observed exactly the same with the Plymouth I used to own. E10 may only be 2% lower than regular gasoline's energy but I see a much bigger difference than that in real use (about 10%).
As for the knock sensor, I would expect it would be used less often with the 91 grade than the 87 grade.
It's actually less than 1% of a difference in energy. I'm not doubting your experience, I'm just saying it wasn't because of E10. If you can notice that much difference in a regular car, the difference would be readily apparent in the Insight, and it is not.
And that's exactly what I'm trying to say. The knock sensor in the Insight is used extensively, every time you drive, regardless of what kind of fuel you have in the tank.
I ran a tank of regular and a tank of Premium to see if I could notice any difference in the numbers, but it was too much data for me to take in.. I would have to log it.
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"I'm saying it's likely people who are able to notice a difference with high octane fuel have carbon build up in their combustion chambers, possibly from burning oil."
Thats possible, even probable. I have extensive idleing hours from all the years of traffic. While the short term may be a placebo effect (more power etc) Im inclined to beleive there is an improvment (based upon my etended range in miles). I do agree though, aside from what i have seen on the scanner, a full data log would be needed to see the true, full outcome of the results.
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