100% Gasoline vs 10% Ethanol
I have always heard that 100% gasoline is better for your engine. I have always payed a premium for 100% gasoline versus gasoline with Ethanol whenever possible. The other day I stumbled across and...
Forum Discussion
GaryUT wrote:
Almost every vehicle calculates alcohol percentage. The PCM uses the O2 sensors and the evap system to calculate the alcohol percentage every time fuel is added to the tank. This is one of the data points used to set fuel trim.
Octane is calculated using the knock sensors and engine load, and timing is adjusted as needed.
Gary
You give O2 sensors way too much credit. It's a rather dumb device, not much better than an on/off switch. Wide band sensors which are used by people that race, have increased capability. OEM's for most gas engines use a cheap sensor. I don't know if vehicles certified for E85 use a sensor with finer resolution.
