Okay, I've made a VERY interesting discovery.. at least IMHO it is very intersting.

Since getting a hybrid I've been bitten by the hypermiling MPG bug. Now, I don't always hypermile, but I do always watch my MPG.

Some time ago someone here listed the suggestion of using Tier 1 gasoline for optimal MPG. Tier 1 costs more than regular grade gas, but it does provide an improvement in MPG. But it can't be missed that in this time of skyrocketing gas prices... the increased cost of Tier 1 is significant.

It also represents a significant amount of money to a gas station that is selling Tier 1 gas.

Let us do some simple math.

Many average gas stations have tanks that hold 2,000 to 10,000. If we work with 30 cents as the average difference in price between cheap gas and Tier 1... this represnts $600 to $3,000 each time a gas station goes through their tanks.

I watch my MPG like a hawk, and I ALWAYS fill up at gas stations that are supposed to be selling Tier 1... but as soon as I fill a tank and see my MPG drop to 30 or lower... I know I just got sold cheap gas... but it was sold to me as Tier 1 gas and it was sold at Tier 1 prices.

After getting stuck like this a couple times I realized a gas station owner in these difficult financial times who wanted to make an extra $3,000 a week could easily fill his tanks with cheap gas then sell it as high quality Tier 1... and THAT is exactly what is happening.

The MPG meter on my hybrid is now a crook catcher... and once I catch a crook I'll never go to his gas station again.

I don't know of any gas station owners that fill up their own underground storage tanks. That job is left to the distributor of the oil refineries. So if it is the case that you're getting a different type of gas when you're paying for Tier 1, then you should place blame on those guys who drive the big oil rigs, because they are the ones that pump it into the ground.

Also keep in mind that the quality of gas (which could affect your MPG) varies depending on the gas station you are at. I. E., Acme gas Vs BP.

Hmmm. I have to disagree. Most all of the gas comes from the same place. The refinery in NJ sells to all the major chains, BP, Shell, Exxon etc.. It is the same gas, just going to different dealers. Secondly, you never get 100% tier 1 or super because most pumps run all three grades through one hose. The hose is about 1 1/2 inches ID and 12-15 feet long, thats a lot of fuel (which the last user got regular) and at least 1-2 gallons will be mixed into. And my final 2 cents, Tier one or super is actually less powerful (explosive) than regular. It has an added retarding agent which allowes it to reduce knocking and pinging by delaying or lessening the possiblity of early detonation. The retarding additive makes the fuel less combustable therefore (my assumption) reducing the energy it can produce. Anyone out there working in a refinery should be able to confirm my belief.

Hi,

First, TheSpoils, tier 1 has nothing to do with octane rating. Tier 1 is a marketing scheme where several companies agreed to sell gas at a certain purity with a certain cleanser additive that supposedly gives greater gas milage. This is in all grades of gas. I have seen a slight difference in Shell gas over the others, but on the whole I have not seen much of a difference among quality name brands. There is more then one refinery, even in NJ.

Second, Marianne, individual stations may be privately owned even if they are part of a franchise. They may have older equipment that, as TheSpoils mentioned, may not give as pure a gas as others. Cheating does occur, and you should not go to a place you can't trust. Be aware, however, that just because a place is listed as tier 1, it does not mean their gas is better, it just means their parent company agreed to be in that group and sell that gas.

Also, many cities and states mandate additives like ethanol at certain times of year. Tier 1 is only based on gas based on the standard. If ethanol is mandated, then that gas no longer meets the tier 1 standard even if it is sold by a tier 1 station. This would not be their fault. My entire State (NJ) has additives in all gas at certain times of the year, but where you live it might be by area. Your station at home might sell better gas then the same name brand station where you work, because it may be in a different zone.

Tier 1 gas is mostly marketing. Companies are constantly coming up with new ways to keep more of our money. (Remember when self-serve was supposed to save US money.) Find a station with a consistent quality that you trust and stick with them.

I buy tier 1 Shell and the price difference from other stations for regular is not 30 cents but usually 2 or 3 cents. the There is a 5 cent per gallon discount if you use a pre-paid card which brings the price below the posted cheap gases. This is true in Pennsylvania.

Here's the critreia for Tier 1 gas:

http://www.toptiergas.com/deposit_control.html

It's all about the additive package for deposit control and includes ethanol as a additive as well:

1.3.1.2 Base Fuel. The base fuel shall conform to ASTM D 4814 and shall contain commercial fuel grade ethanol conforming to ASTM D 4806. All gasoline blend stocks used to formulate the base fuel shall be representative of normal U.S. refinery operations and shall be derived from conversion units downstream of distillation. Butanes and pentanes are allowed for vapor pressure adjustment. The use of chemical streams is prohibited. The base fuel shall have the following specific properties after the addition of ethanol:

1. Contain enough denatured ethanol such that the actual ethanol content is no less than 8.0 and no more than 10.0 volume percent.

It also includes all grades of a retailer as well - not just premium.

Here in my part of New England the only Tier 1 gas available is Shell and I pay no more for their gas than at other retailers - $3.11 for regular on my last fill up.

I will have to try the shell tier1 for myself. I use the cheap wawa gas right now. Thanks for the insight into tier 1.

The first statement is definitely not true if you're comparing gasoline formulations between different regions of the US. See http://www.exxon.com/USA-English/Fil...p%20100102.pdf.

In my old post at http://priuschat.com/forums/prius-ma...tml#post236235, I mentioned that Chevron CEO mentioning there being 18 different formulations of gasoline. http://www.energy.ca.gov/gasoline/ty..._gasoline.html mentions 10 different gasoline formulations and I'm not talking about regular, midgrade and premium.

06 Toyota Prius, 04 Nissan 350Z; mom has 07 NAH

Ok allow me to rephrase my statement. Gasoline produces approx 125,000 BTU or 131 megajoules of energy per gallon. That number should be consistent, So ... the difference between exxon, shell, wawa is? A 100 watt light bulb produces the same 100 watt worth of light regardless if it is a GE or Phillips or Sylvania...etc
But as posted earlier, I'm still going to try the so called tier 1 and will post my findings.

I think we've got a whole bunch of confused posters here and people talking about different things. What the heck do people mean here when they're talking about "tier 1"? Are they talking about http://www.toptiergas.com/ or are they higher octane gas? http://www.toptiergas.com/ has nothing to do w/octane ratings. I don't know what "tier 1" is.

As for BTUs per gallon, it's not so easy to say it's just 125K BTUs per gallon. Take a look at http://209.85.173.104/search?q=cache...ient=firefox-a for instance. As I stated earlier, there are many different formulations of gasoline in the US which can definitely affect its energy content. Too bad I'm not a chemist, petroleum engineer or automotive engineer.

As for "A 100 watt light bulb produces the same 100 watt worth of light regardless if it is a GE or Phillips or Sylvania". That's not true either. There are longer life incandescent bulbs that have lower light output (measured in lumens) than conventional bulbs. Unfortunately, I don't think I can send you working links but if you go to http://www.sylvania.com/ConsumerProd...eneralPurpose/ and look at the 1st Double Life Soft White Bulb (product #11332) vs. a regular Soft White (product #12770), you'll see the former emits 1530 lumens vs. 1690 lumens. The former lasts 1500 hours while the latter lasts 750 hours. I personally have some of the double life bulbs.

06 Toyota Prius, 04 Nissan 350Z; mom has 07 NAH