Coincidence?

[Fadec40]

Has anyone experienced anything like this?

I have a 98 328i. When I got the car, I began using Sunoco 91 octane. Performance was good, no knocking. But, just like clockwork, a day after I filled the tank with gas, the check engine light came on. Got the fault code, replaced gas cap. Good for two weeks. A day or so after every fill up at the same station, check engine light came on. Same code everytime..

The slow learner I am, I went to Amoco 93 octane.

No check enginel light for three fill ups now.

has anyone experienced anything like this with fuel?

[Furious]

sometimes i get a bad tank of gas, if that happens i usually use an octane booster to level it out a bit and my car runs good.

[Deloriant]

Could be the stations cheap gas that they use....but you shouldn't need 93 octane unless your car is heavily modded.

Are you always screwing on your gas cap properly?

[BlantonG13]

93 octane is yummy...the owners manual states that you should use 91 octane for best performance and results. It doesn't hurt to wash your system out with 87 or 89 every now and then...

[Turbodefrost]

So what is better, to put 89, 91, or 93 octane? I've been told many different things, so now i'm just confused. used

[Turbodefrost]

oh, ok, that wasn't there when i asked this... Good to know

[BlantonG13]

thats been happening to me all day...haha. Its like the site is lagging or something. I've been hitting the refresh button nonstop...Its probably just the cookies set on my computer...

[Kevin325i]

You can also check ethanol content in the gas, ethanol collects moisture so if you live in a humid area try and find a station that uses less ethanol. 10% is the lowest I can find around here, but it's 93

And on my gas door it says "premium unleaded fuel only" so screw what my manual says. Actually I'm pretty sure it says 91.

Kevin

[wulley1]

inside the gas door, mine says 89. I've tried everything, and it doesn't seem to run better or worse. Around town, I use 91, but on long trips I use 87. I've never seen a difference in gas mileage or peroformance, but that's just my car.

[Fadec40]

The label on mine says 89. I went with the 91 becuase, for me, the car did run noticeably better. The reason I went with 93 was to see if that check engine light would stay off with a higher octane. It did. I am planning on venturing back to 89 or 91 from another gas company. Like I said, I replaced the gas cap the first time I got the light. As for the gas being cheap, it was Sunoco, not JOE's GAS.

[Kevin325i]

Yeah my car is finicky. It only takes mobil 93 octane or the plugs foul

[Fadec40]

Another tidbit is that I noticed a little better mileage with the 93.

[Mark31186]

Ive used 93 since i got my car...... and yeah from mobil... like kevin hehe i need it for my chip too well 91 for the chip but it said 91 or higher so thus = 93 octane

[Rookie]

93? The hottest fuel I have been able to find is 91 premium. The only place close I know of is over an hours drive and a trip over the board into canada to get 94.

[spieluhr]

i think the car can definately tell a difference in different station's gas. I usually fill up with Chevron Premium 91, but one day i went to the Shell and used that new V-Power Premium and the car ran ok but it seemed like the engine swallowed the gas, i had the worst gas mileage ever.