Shell Gasoline...Better?

[Eddie]

My opinion is that if you use/get the correct octane then all gas will run as gaood as any other in the short term. I feel the name brand gas and especially top tier (Chevron & Shell in my town) do better over 10s of thousands of miles becaue of the injector and fuel system additives. Just my thoughts. I mix & match. two fill ups with name brand to one off brand like Murphy at Walmart.

 

[Craig in Canada]

Originally Posted By: Eddie
My opinion is that if you use/get the correct octane then all gas will run as gaood as any other in the short term.


My experience is directly contradictory to that, depending on the sensitivity and performance category of the engine involved.

In my case I was always running Sunoco Ultra 94 in Southern Ontario, Canada. I would usually buy from the same (busy) station but sometimes bought in other locations. I could observe tank-to-tank variability in the fuel quality with this engine (which called for a range of 91-93 AKI).

During the 5 years I owned this car I only had 3-4 truly exceptional tanks of gas. I would say in general that fuel in my area is subpar compared to the southern US, for example. This trend is also observed by less demanding vehicles owned by family who snowbird to FL annually.

 

[i6pwr]

Originally Posted By: Craig in Canada
In my experience (which is far from all-encompassing) I haven't run across an ECU/DME that tracks when you fill up and takes that as an opportunity to test the map at full advance.


The ECM will do that exactly, but from the extremes of full retard to full advance, it's alot of parameters to cover in milliseconds. I believe the reason there are different tables is to give the ECM a narrower bank of values to look at, if you have low octane, there is no need to even apply full advance so it's removed from the equation and allows for a smoother response.

I know my 02 GMC has this, so I figure this is likely around in many other ECM's...I just don't know that 100%

 

[Eddie]

My opinion was based on my experience with 4 vehicles. 1986 Saab, 95 Jeep GC 4.0, Subaru 2.5L and now my Mazda CX 7 which is turbo charged. I found no difference in gas mileage or performance whether using Top tier or Murphy gas.I use Major brands most of the time for the fuel system cleaners in them. Respectfully Ed Hayes

 

[i6pwr]

Originally Posted By: Eddie
My opinion was based on my experience with 4 vehicles. 1986 Saab, 95 Jeep GC 4.0, Subaru 2.5L and now my Mazda CX 7 which is turbo charged. I found no difference in gas mileage or performance whether using Top tier or Murphy gas.I use Major brands most of the time for the fuel system cleaners in them. Respectfully Ed Hayes


10-4

I agree that unless your vehicle calls for the high octane it's just money down the tubes. As for the tables....could be a GM thing only....I dunno.

What kind of mileage do you get with that CX-7? Was looking at those recently along with the RDX, but the Acura got bad reviews for ride harshness.