Different % nitrometane change ignition temperature?

[unclechimist]

Hallo, I’m new in this forum. I came from the world of modeling.
I have some doubts about chemical processes inherent in that environment and some questions for you. I hope you can help me.

The first thing to ask is to help resolve this apparent contradiction:
consider two basic mixtures used: methyl alcohol and nitro methane.
Data sheets shows that the methyl alcohol has ignition temperature to 12° C, boiling point to 64.7°C and autoignition temperature to °464, density 0.79 (some data shet reports 400°C)
The nitro methane has an ignition temperature to 35° C, a boiling point at 100.8°C, and, though a temperature of a auto 418°C degrees, density 1,13
How do I explain this? From layman I would expect that the auto of nitro methane occurs at a temperature greater than that of alcohol-methyl.
Which data shet is correct?

Prepare now two mixtures using as a base methyl alcohol: the first with a 5%, percentage of nitro methane, the second with a rate of 40%.
We havegot a simple motor. On top of the cylinder, and inside it, there is a glow plug that, through electricity, bring to a temperature sufficient to trigger the less "Heat" and then leave at the same temperature for the subsequent mixture test.
Injected into a cylinder the 5% mixture so that the air inside the cylinder and the oxigen released by nitro methane are exactly the quantity used to burn the total mixture.
Through the rotation Axis, we climb the piston regular beginning to collapse liquid and air. Let us assume the compression ratio of the engine is 6 / 1, which is the initial volume of the cylinder is 12 cc, at the end of the stroke volume will be reduced to 2cc.
At some point, the mixture reaches the autoignition temperature.
We repeat the test with the mixture to 40% of nitro.

Which of the two mixtures, in the condition indicated (each with the proper amount of air and equal temperature of plug) will go first?
Once lit, as will be different the two combustion in pressure, temperature and expansion speed of the flame?
Thanks.