I used Shell when I went to TX a couple a months ago. It was about the only name brand gas I consistently saw with the exception of BP (which stinks) and had no problems with it at all. Locally I use Sunoco most of the time and give Citco a run now and then but location does play into the equation as Vic said

 

I'm not sure I agree with this, but my math is pretty fuzzy sometimes.

If the differential between 87 and premium pretty much stays the same, the only way to make up the difference is to get more MPG from your fuel. I can't see how you can recover the cost at a faster rate just because the overall price of both 87 and premium raise equally at the same time.

On topic, I'm a big fan of the chip mod, but have no opinion on what to do first. I've never had an 87 tune, but my truck is not a daily driver. I mostly use Chevron gas in my L and I'm very happy with it.

 

The point being made is that they don't rise equally. Usually they keep the differential between the grades the same in cents. If 87 goes up from $2.29 to $2.39 then 93 goes up say from $2.49 to $2.59.

The percentage increase is:

87: $2.39 / $2.29 - 1 = 4.37 % increase
93: $2.59 / $2.49 - 1 = 4.02 % increase

If you knew exactly how much mileage you were gaining you could set up an equation to determine at what price point the mileage offset the higher price.

You can get a good guess at the break even point by this approach.

$2.49 (93) / $2.29 (87) - 1 = 8.73 % higher price.

Therefore 8.73 % better gas mileage will put you close to break even. So my city mileage of 15 mpg would have to increase to 16.3 mpg to break even on fuel consumption.

The issue with a performance tune vs say an intake mod is this. With the intake mod you don't have to change to a higher priced fuel, so the cost of the intake mod can be paid back over time by the improved mileage. With a performance tune that requires more expensive fuel, you first have to overcome the higher priced fuel before you can apply mpg savings to recovering the cost of the mod.

My rule of thumb is that intakes and to a certain extent exhausts can possibly pay back over the life of the vehicle. Performance mods have to be justified on power gains alone rather than fuel savings.

Just my 2 cents worth.

Enjoy.

 

Yes, that point DOES hold true - meaning, even if premium gas goes to $5.00 a gallon, regular will still be $4.80 a gallon - the overall national average between regular and premium stays at approximately 20 cents per gallon.

Yes, there are a few areas where jerks are gouging and charging a larger differential, but by and large it stays the same.

Back in the 60's, when Sunoco 260 was 39.9 a gallon, Sunoco 190 was 19.9 a gallon - when gas went to 50 cents a gallon, premium was still 70 cents a gallon, when gas hit $200 a gallon, premium was still $2,.20 a gallon - and so on.

SO that being a fact that has stood the test of time for decades, it's obvious that the higher gas prices go, the less MPG gain you need to see in oder to break even or even spend *less* actual $$$ for gasoline when using premium gas that is properly tuned for in *our* custom tuning - and *that* was the point.

There is no way, short of using grep fuel or driving the vehicle harder, that you're NOT going to see an increase in MPG between running on the factory program on 87 octane gas versus running on our premium gas performance tuning and using good quality premium gas - the only way you can prevent that from happening (assuming you actually calculate MPG properly) is either by driving the vehicle harder, or by using "cheap" gas that has a lower BTU(energy) content. The principle is as sound as it gets, the BSFC drops every time.

Just some general FYI for you there, Lyfisin, that I hope explains this better than I did the first time around!