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Gas Quality

My Jeep Commander 2006 (a problem vehicle until i had it repaired/much replaced by non-dealer service center, i.e., i know that these are ‘finicky’ cars on their best days), the engine light comes on steadily/not flashing indicating poor quality fuel. It did this 60mi after this last fill up at the gas station, and it did so after 60mi following the previous fill up. The engine light then goes off -as Jeep told me it would - after driving it about 60-70miles. this happened a couple of times last summer as well. I’ve tried going to different gas stations in the area thinking different stations would have different fuel suppliers, but what i noticed is that BP and Sunoco for example are getting delivery from same truck. ?: how can i determine quality of gas before I put it into tank? I always put in premium but it doesn’t matter what the label says if the quality isn’t any good.

Using a Top Tier gasoline provides some assurance that the fuel meets quality standards. Other than that, you’re pretty much dependent on your past personal experience.

I am less sure your check engine light is a direct result of fuel quality. Usually the CEL means there is an issue between what the front sensor and rear sensor is reading, and that issue is not necessarily poor quality fuel. Has anyone told you what the codes set are, when this happens?

A check engine light does not indicate poor fuel quality, head over to Advance Auto, Pep boys or a similar ‘McPart’ store and have them read the code for you. Most places will do that for free. Once you have the code # (ie P1234) post it back here and someone will be able to give you some guidance. Since it is happening after a fill up I suspect a problem with your gas cap not sealing correctly. As you noticed with BP and Sunoco a lot of gas comes from the same refineries and same distribution centers, the only difference might be the additives each brand puts in.

Thank you I will do just what you said! And, I love your radio program. Prior to this car I had a Jaguar, and the radio show helped me know how best to maintain that car well and economically.

We don’t know what’s making your CEL come on but it’s not fuel quality…Also, every penny you have spent on premium gas has been wasted too…Jeeps run fine on regular…

I know,I had 2 Jeep Wranglers prior to the Commander that ran perfectly well on regular. It’s just that I had so many problems with this Commander that I want to only put the best into it; give it the best opportunity to run well. I was told it could be gas cap but I didn’t believe it. I’m going to do that scan this week, and get the new gas cap.

I want to only put the best into it

Just remember that octane is not an indication or measure of quality. It is only a measure of how fast the fuel burns. High octane means it burns slow. Some cars need high octane (usually high compression engines (performance cars) Using high octane a car not designed to take advantage of the higher octane is a total waste of money.

oh alright i had no idea. i thought it was measure of quality. thank you. what i save going forward this month in gas-$, I will use to pay for new gas cap…