Brand of Gasoline

[Louis-Alain Richard]

Spent the night with my good friend Lucian, a mechanical engineer that is a
tech/sales trainer at BWM Canada. He also translate and writes the teaching
material from Munich. He knows a bit about cars, let me tell you.

I've asked him about knock sensing in BMW engines and he said that knock is
monitored all the time. Even on the highway at part throttle. More, he said
the ECU will try to advance timing all the time, until knock events are
detected, and then back up a bit. It will do that again and again and again.
That way, the ECU knows that it extracted the last bit of energy from each
liter of fuel for any conditions (temp, speed, gradient, atmospheric
pressure, etc). 

This fact do confirms the theory that Premium fuel is not only for WOT
events, but is beneficial all time on an engine that is mapped for it. 

And regular gas is detrimental for such engines... 

Picture the G37 IPL convertible that I drive this week. I'm SURE the
preceding journalist didn't fill her up with premium. At low speeds, 25 mph,
I can clearly hear knock with a steady throttle when the 7-speed auto trans
gently upshifts. And every time I accelerate the tiniest bit... Sounds like
an old Tercel from the 90's.

Fuel economy is appalling : 17l/100km in town, that is 14 mpg.

Will empty the tank this weekend and report back with Premium.

Louis-Alain