Improves Engine Performance

Your local gas station probably offers you 3 levels of gasoline, like
gold, silver and bronze. These typically have different levels of
octane in them and you will generally get a little better mileage for
the more expensive type.

In addition to different octane levels there are many different
additives that can be in a companies brand of gasoline and this
differentiation can have a big impact on your vehicle.

One type of additive is a detergent which generally cleans your
engine. Without some level of detergents engine deposits form and this
causes reduced fuel efficiency, acceleration and power as well as
increasing emissions and rough idling. more....
http://www.zone-car.com/?gasoline-detergent-improves-engine-performance.php

 

Saturn has a flyer of recommended gas brands and also recommends Chevron
Techron additive for older cars.

 

The OP is a zone-car spammer with idiotic information.

 

According to a newsletter from www.Autotap.com when trailer towing (or
anytime under a heavier than usual load), a higher grade of fuel will
actually help mileage. Reason is that any pinging sensed by the knock
sensors will cause a retard of the timing or mixture enrichment. This was
part of the newsletter touting the digital dashboard enhancements that run
on a PDA with the autotap software. The virtual gauges could show fuel trims
and spark advance in near real time. One of these days I have to play with
that a bit.

Other than that, I use a can of injector cleaner every couple of months and
run regular gas (includes 10% ethanol here in NY). So far, so good.

Oppie

 

I've also noticed that Shell gas runs worse in my SC2. Weird. I cant burn
rubber anymore when I fill up twice on shell. Switching to any other brand
seems to restore mild power back to my car.

 

Interesting that you mention that about Shell. It is one of the least
expensive fuels in this area. I tried it a few times and would guess that I
got between 10 to 20% less mileage on a tank than the BP that I usually use.
I don't recall the lw300 saw any difference in power. Then again I bought
the Shell when gas was near $4/gallon last year and it was all about the mpg
and not even trying for power...feather-footed on the pedal and all that.