08-03-2023, 11:51 AM
I can't see the small theoretical difference in normal and premium petrol showing up in the performance when running a Seven.
A few years ago, a fuel trial was done using a friends 1920s side-valve Vauxhall where kerosine - heating oil - was added to the normal petrol and a satnav used to see if this improved top speed and therefore performance. The top speed was measured on repeated averaged runs up and down a quiet stretch of dual carriageway. The results suggested that the addition of 10% kerosine gave a bit more power. I seem to remember a couple or so extra mph translated to about 10% more power from the engine, given the cube power law for increased speed (drag being squared, and resistance linear) versus power output. So, even this significant change to the fuel composition had little effect and wasn't worth the bother.
A few years ago, a fuel trial was done using a friends 1920s side-valve Vauxhall where kerosine - heating oil - was added to the normal petrol and a satnav used to see if this improved top speed and therefore performance. The top speed was measured on repeated averaged runs up and down a quiet stretch of dual carriageway. The results suggested that the addition of 10% kerosine gave a bit more power. I seem to remember a couple or so extra mph translated to about 10% more power from the engine, given the cube power law for increased speed (drag being squared, and resistance linear) versus power output. So, even this significant change to the fuel composition had little effect and wasn't worth the bother.