TheDosDog

I know there is a lot of debate on what grade of fuel is best to use in the 8 but now there appears to be another significant concern. Being fairly close to both the auto and petroleum industries I have always been of the mindset that gas is gas, knowing all fuel originates from just a few refineries and the only real difference is additives. Well, not true any more. Fuel with excessive sulfur content is being sold in select US markets (California is one of them) mostly through the off brand independent stations. As a result automobile manufacturers are seeing increases in warranty claims for fuel system related failures. While the performance characteristics of this fuel is comparable, the high sulfur content makes it more corrosive, damaging O2 sensors, fuel sending units and in some cases even corroding fuel lines. I recommend staying away from off brand fuel unless you know they get their fuel from one of the major refineries (Shell,BP etc.).

Edit: It appears some of the majors are doing this too. See Nubos post regarding Shell in the south east.

kbull

This has nothing to do with the octane rating, then? If I were to get 91 octane from some no-name station, that would be as bad as 87 from the same station?

TheDosDog

Correct, this related to the quality of the crude and the refining process. Not the octane rating.

MazdaManiac

iTrader: (3)

This is interesting to me.
Though this has been a point of contention with me in many discussions that I have had with others about fuel quality and specs beyond AKI, I'd like to see your data on this.

Where have you seen published reports on sulphur content? That would be good information to add to my compendium of fuel information?

ivyrose

Ok, so with that said is there going to be a significant difference between 87 & 91 from a brand name source?

Gyro

We don't have 91 where I live. its only 87,89 and 93 for grades. I use 93.
I did use 87 once because the other grades were not pumping. I have 0 gas and needed to buy some where i was. I saw absolutely no difference in performance. It was only a one time thing.

what are the grades available in parts where 91 is available? 89 91 93?

TimH

87, 89, 91

Sea Ray

This happened a few weeks ago in Louisville, Ky. A bad batch of gas caused numerous vehicles to have to have the fuel gauge sensors replaced, and it might have been too much sulfur. Most of the cars ran out of fuel even though the gauge showed some left. The gas company paid for the repair which was pretty expensive for most people, about $500-600. I don't remember the brand but I don't think it was not a major one.

neit_jnf

I've seen 86, 87, 89, 91, 92, 93 and 94 unleaded and 110 leaded

310Guy

If you change octane it usually will take a tank or two to see any difference...

rx8spiritR

well, can you actually feel the difference between 87 and 91? who put 87 in his 8 here? and does it feels the same as 91 to you?

Nubo

Actually, in this report, Shell was the main culprit...

MazdaManiac

iTrader: (3)

Which report?

TheDosDog

Fuel supplies are regional and based on refinery production in a specific region. Many brands "even majors" share supply from the same refineries. There may be no way for us to defend against this issue if we are in a region receiving high sulfur fuel since many stations in a region receive fuel from the same suspect refineries.

Nubo

notice the word "this" was underlined. It's a hyperlink -- click it to go to the report.