Poor Fuel Economy solved!? Maybe

The red and gray lines do overlap indicating identical performance.
The only way that makes sense is if you've already had it explained to you. That would not be possible looking at the graph without an accompanying explanation which happens to be my belabored point.
 
The only way that makes sense is if you've already had it explained to you. That would not be possible looking at the graph without an accompanying explanation which happens to be my belabored point.
Well, now you’ll be able to share this knowledge down the road in the best way you see fit (if you so choose)! :D
 
Well, now you’ll be able to share this knowledge down the road in the best way you see fit (if you so choose)! :D
I wouldn't venture to share this knowledge. While the explanation is quite believable I have no way of verifying it.
 
If you have experience with torque and horsepower graph this graph is very clear, if you don’t then yes i can see there could confusion. Torque and horsepower are almost always shown like that with both curves on the same graph, because in reality, horsepower is just torque multiplied by the RPM. (Horsepower = Torque x RPM / 5,252). And the fact that the formula is divided by 5 252 means that the torque and the horsepower always crosses each other at 5252 rpm.

There is no harm in suggesting more explanation is given as hardrightedge did, but it is also not expected to have to do it every single time. This is a thread about valve carbon deposit. With the amount of technical information in this thread on the various topics, i also wouldn’t have expected to have to explain the graph anymore than it is.

But as long as questions are answered when members ask them when they don’t understand the graph, i don’t see any harm in posting it.
 
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The red and gray lines do overlap indicating identical performance. Like you said, the red covers the gray (mostly) until there is a difference in performance. If it weren’t for yrwei sharing this graph over and over again, we’d never be able to squash the “does higher octane yield X?” questions that keep cropping up. Yrwei to the rescue! 😄
If we magnify the power curves between 3,600 ~ 4,000 rpm, we can actually see the red lines (AKI 87 fuel) are a bit higher than the gray lines (AKI 93) on both torque and hp.
 
It is implied that the red line has the data for both octanes, otherwise it would mean that the car goes 0 mph until the revs go over 4,500 for the grey line lol. I can sort of understand people thinking "Where is the grey line?" when first looking at a chart like that for the first time.
All of us are just trying to inform one another or to correct one another, not to frustrate people or seemingly insulting people's intelligence. Yrwei52 is always very through and he is a very smart man, which gets me so frustrated from him correcting me all the time! He is so frustrating!!! Haha just kidding :)
 
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