Why do you have to use Premium Gas

[JoeManNorth]

LMAO! nicely put

 

[JoeManNorth]

let's say you save 20 cents a gallon at the tank by using chummy 87 octane piss in the tank. so for a 12 gallon fillup you saved a whopping $2.40. if you fill up twice a month you just bought yourself a #1 at the golden arches. so by not using premium gas, for whatever reason, you've saved $57.60 a year or the equivalent of a dozen big mac meals per year. congratulations.

 

[blueballmp3]

okay what i seem to understand is that the timimig on the ecu is advanced when runin 91, but retards the timing if you use the 87? if so how say youve been runing 87, how do you get the ecu to go back to the advanced setting?

 

[bazooka joe]

hope this helps:
An engine control unit (ECU) is an electronic control unit which controls various aspects of an internal combustion engine's operation. The simplest ECUs control only the quantity of fuel injected into each cylinder each engine cycle. More advanced ECUs found on most modern cars also control the ignition timing, variable valve timing (VVT), the level of boost maintained by the turbocharger (in turbocharged cars), and control other peripherals.
ECUs determine the quantity of fuel, ignition timing and other parameters by monitoring the engine through sensors. These can include, MAP sensor, throttle position sensor, air temperature sensor, oxygen sensor and many others. Often this is done using a control loop (such as a PID controller).

 

[Captain KRM P5]

okay what i seem to understand is that the timimig on the ecu is advanced when runin 91, but retards the timing if you use the 87? if so how say youve been runing 87, how do you get the ecu to go back to the advanced setting?

i don't think the MP3 ecu retards timing when you toss 87 into it. i think it will probably ping or detonate even slightly so if this is done. someone can correct me if i am wrong.

 

[flat_black]

Yeah, actually, if you put 87 into it, the engine will ping/knock, which the knock sensor detects, then retards timing... So, by the nature of the beast, yes, it does actually retard timing, but only because the knock sensor is registering trouble.