No worries, just wanted to keep everthing in perspective. I think I'm going to stick with Shell and run a tank of Mobile every 5th or 6th tank.
I agree I used nothing but Amaco but now it's BP and I'm not sure it's the same. Amaco was a very clean gas.

 

I prefer shell

 

Evo is the only mag to carry a really good test of gasolines and its findings are applicable here.

My gasoline experience is strictly in the USA and comes from being a consumer of gasoline -- lots of it from driving big miles in my cars (120K in a '96 Mustang, 28K in an 02 Camaro (in 4 months), 120K miles in an 02 VW Golf TDi.... oh this doesn't count because of course it burned diesel, 257K miles (and counting) in my 02 Boxster, 40K miles in an 06 GTO, and now over 85K miles in my 03 Turbo) -- and during many of these miles have used supermarket gasolines -- gasoline sold by a discount gasoline station -- and with my Boxster have found the CEL comes on more readily using this gasoline.

I reverted to using discounted gasoline when gas prices spiked a few years ago.

When I switched to in this case Shell gasoline the frequency in which the CEL came on dropped. It didn't stop coming on entirely -- weak converter and no gasoline is going to restore the converter -- but it just so happens the converter is marginal enough it is sensitive to gasolines and I believe serves as a canary in a coal mine regarding gasolines.

And I ran strictly the discount gasoline and then strictly Shell long enough over many tanks fill ups and over many months of driving and at two different times when gas prices spiked up and the price difference between the two gasolines enticed me to buy a discount gasoline in order to save money on my monthly gas expense. In both cases using the discount gasoline and Shell the driving conditons and climate conditions were consistent that the results gave myself plenty of confidence that the frequency of CEL coming on was due to the gasoline and not other factors.

More recently I was talking with a Porsche tech about gasolines and he told me of a class he had completed not too long ago -- this class was held down in southern CA and given by PCNA -- in which the instructor brought in two samples of gasoline bought at local stations.

One sample came from a supermarket gasoline station, the other from a top tier gasoline station.

The instructor poured some gas from each container into a clean beaker and added a similar amount of distilled water and then stirred each sample.

Solids appeared and settled out of the supermarket gasoline while the top tier gasoline remained clear.

Convinced the tech there's a significant difference in gasolines. I didn't need any further convincing.

Sure, you can run whatever gasoline you want but me I'm staying the heck away from discount gasolines based on what I've observed over the years.

Both of my cars receive a steady diet of mostly Shell in town, because there's a busy Shell station handy and it offers gas at a lower price than nearby Chevron and Unocal/76 stations. On the road I seek out Shell but will use other top tier brands if no Shell station is handy.

Sincerely,

Macster.

 

Something that will blow your mind! Goto several gas stations and put gas in 20oz Soda Bottles, label them and then freeze them in your freezer and see the difference in fuels. Most fuels have 7-10% water in them but some cheaper fuels have 20%+ water and you will also see weird frozen colors.