Effect of low octane gas?

[FX-MAN]

I have the same problem as the guy above. At about 4000rpm my car is having a total loss of power (like the turbo is just not working).

However, I always fill up with 92-94 octane (whatever the highest octane is at the station). Could brand make a difference? I did go to a cheaper non-national-chain gas station...

This is the second time this week that it's happened though, and its really annoying me.

 

[Da 6]

not all gas stations follow the strict octane ratings. Some have bad gas in general. I remember in texas shell was the don't go to stations cause people were missing like crazy and V8 owners were at one point only running 5-6 cylinders. Try a difrent brand of gas. Whats your location? If you are in the 48 try using cheveron with techron from gas station or in the 20 gallon concentrated formula.

 

[seanw]

I have the same problem as the guy above. At about 4000rpm my car is having a total loss of power (like the turbo is just not working).

However, I always fill up with 92-94 octane (whatever the highest octane is at the station). Could brand make a difference? I did go to a cheaper non-national-chain gas station...

This is the second time this week that it's happened though, and its really annoying me.

I only had this problem b/c the dealer apparently filled up the tank with 87 octane before handing it over to me. I checked with them and they confirmed this. Now that I've filled it with 93 a few times, it is running normally (ie., great!). I have heard that non-nationals stations are more likely to have old tanks which allow water to get into the gas somehow. These days with the strict environmental requirements, it seems unlikely that this is true, but you never know.

 

[Nando 6i]

Higher Octane Fuels

about using higher octane fuels and power:

As mentioned earlier, higher octane fuel burns slower that's why it's more resistant to pre-ignition / detonation. To extract more power out of it the ignition has to be advanced to provide a longer burning time before the exhaust stroke. If the PCM is programmed to maximum safe ignition advance with 93 octane, then using higher octane may slightly reduce power because it will burn slower and less power will be extracted. At the same time it will provide a bigger margin of safety against detonation; that's why even though my RX-7's ECU is programmed for 91, I always use 93 or 94.

Now, some cars will continue to advance timing until detonation is detected, in these cases 100 or 110 octane race gas will provide more power.

You guys got a little bit to technical for me (boom07) but I think from what I read is that higher octane WILL reduce power on for example a Mazda 6i (No Turbo) but not on a Mazda 6 with Turbo...correct ?

Finally, since 91 Octane is a more of a controlled burning fuel. Would it be safe to say that if you want to get more miles out of for example, My Mazda 6i can i put 91 Octane (note: not caring about loss of power)? But in the future (say 2 years from now) switching to 87 Octane (due to the fact that I will be modding my 6i)?

Your inputs would truly be appreciated?
Thank you.

First Mazda
1990 MX 6 (No Turbo) - switched to a 2005 Mazda 6i Hatchback November.

 

[Da 6]

I have a tuner who emails me the tune (SCT Xcal2 Tuner for the other car) and thats how it temporarly runs race gas. Other than that timing/boost never changes untill you drop below the reccomended octane level IIRC.

Anything above 87 in N/A 6 will result in bad gas milage, washed down cylinders, depostis, and not so Zoom-Zoom acceleration.

 

[MS6freek]

i live in montreal and im putting 94 octane daily drive, very good for the car, instant response and all the power is there. (thumb) (first)