Darren, perhaps N2toh was refering to octane, which is the reluctance of gasoline to explode, but rather to push the piston down. High octane gas is almost the opposite of high cetane diesel, and would be a disaster to run in a diesel. because the reluctance to burn would lead to quite a fuel load in the cylinder before it finally lit off (from compression ignition), causing a potentially distructive knock.
I hope you two are'nt starting to flame.
Scott E