What grade gasoline do you use

[Tempus]

<div class='quotetop'>QUOTE(jrfaris @ Apr 13 2007, 03:10 PM) [snapback]422877[/snapback]</div>

Toyota probably get's some benefit from the major producers for including the Top Tier. Or was added by their lawyers, not their engineers (like the I agree button).

You are right that there are some brand differences but the basic gas is the same. The difference is the additives put in, usually cleaners, etc. These may or may not be good for your engine long term. They are often just a marketing ploy.

Anyone who relies on price as a measure of quality is misguided. This would imply that purchasing gas at the most expensive Chevron station by the freeway would give you a better product than the cheaper downtown Chevron.
[/b]

You need to do some research. You clearly don't have any idea what you're talking about.

The Top Tier gas program is a joint effort of the Auto Manufacturers, specifically, BMW, General Motors, Honda, Toyota, Volkswagen and Audi.

They say the 'minimum' detergent quality in gasoline is inadequate for modern motors and they want gas manufacturers to agree to meet what tests show to be good detergency in ALL grades of gasoline (Not just the poorly-named 'premium' grades).

You can go to the top tier site and read the science on why modern cars with modern emissions need more detergents (not just for engine life but for emissions), or google is also your friend in such cases.

When you buy gas from a manufacturer who has been certified 'top tier' you are assured that the gas has good additives. When you buy from the manufacturers who haven't joined, or from joe's corner station, you roll the dice.

[bulek]

<div class='quotetop'>QUOTE(V8Cobrakid @ Apr 13 2007, 06:22 PM) [snapback]422700[/snapback]</div>

This web page (bladder system) has this to say:

OCTANE RATING: At a minimum, the gasoline used should meet the specifications of ASTM D4814 in the United States. For the Prius, use only UNLEADED gasoline with an Octane Rating 87.

NOTE: Do not use premium gasoline. It may cause starting problems with the Prius. There is no gas milage benefit when using premium gas!

NOTE: Starting may occur many times in a single drive cycle unlike conventional vehicles compounding potential "hot soak" issues.

this page explains what a "hot soak" is. section 3.1 All it really says is that a hot soak refers to the evaporative emissions when the engine is off. I have ideas and theories on this but I'll stop with my .02 here.
[/b]

That's interesting. In my country we do have 95 and 98 octane gas. My (EU) Prius manual says one should use 95 or higher. When using lower octane gas than 95 one can lead to breaking of gas engine. Hmm... does it mean the EU engine is considerably different to US version?

- Piotr

Edit: It seems the reason for that is that octanes are calculated differently... 95 in EU is similar to 91 in US.

[jrfaris]

<div class='quotetop'>QUOTE(Tempus @ Apr 13 2007, 12:26 PM) [snapback]422885[/snapback]</div>

The Top Tier gas program is a joint effort of the Auto Manufacturers, specifically, BMW, General Motors, Honda, Toyota, Volkswagen and Audi.
[/b]

So it's kind of like saying use only genuine Toyota parts. They have a vested interest in promoting the program which may or may not be to the financial benefit of their customers.

[Tempus]

<div class='quotetop'>QUOTE(jrfaris @ Apr 13 2007, 04:19 PM) [snapback]422929[/snapback]</div>

So it's kind of like saying use only genuine Toyota parts. They have a vested interest in promoting the program which may or may not be to the financial benefit of their customers.
[/b]

No, it's not.

It's like saying use only good grades of Motor Oil that meet X specification.

Or use only Brake Fluid that meets X specification.

Or use only Coolant that meets X specification.

Or use only Transmission Fluid that meets X specification.

Fuel is just about the only remaining fluid that goes in your car (aside from maybe Washer Fluid), that isn't subject to actual verifiable specifications, which is pretty much a bad thing for both auto manufacturers and drivers.

The manufacturers of all those other fluids have agreed to meet minimum standards. Fuel is still the Wild Wild West.

So, by your logic Toyota has some sort of ulterior motive in specifying the minimum standards for Brake Fluid that may or may not be of benefit to you?

Very confusing train of thought there.

Personally, I WANT the manufacturer to tell me what works well, and what will cause me to run through the red light in front of the Cement Mixer.

[JimN]

I switched to Shell when I got their MasterCard that offers a 5% rebate on their gas. They also have a promotion now that posts a $10 credit after it is used twice at the station.

[jrfaris]

<div class='quotetop'>QUOTE(Tempus @ Apr 13 2007, 04:04 PM) [snapback]423014[/snapback]</div>

So, by your logic Toyota has some sort of ulterior motive in specifying the minimum standards for Brake Fluid that may or may not be of benefit to you?

Very confusing train of thought there.

Personally, I WANT the manufacturer to tell me what works well, and what will cause me to run through the red light in front of the Cement Mixer.
[/b]

Don't believe Toyota is writing the spec for brake fluid. But they are (with other auto makers) for Top Tier gas. To me that makes it similar to specifying genuine Toyota Parts.

[Tempus]

<div class='quotetop'>QUOTE(jrfaris @ Apr 13 2007, 09:01 PM) [snapback]423055[/snapback]</div>

Don't believe Toyota is writing the spec for brake fluid. But they are (with other auto makers) for Top Tier gas. To me that makes it similar to specifying genuine Toyota Parts.
[/b]

Is that a statement of opinion or an imperative?

You don't believe Toyota is writing specs for brake fluid or you're telling me not to believe it? Very unclear diction.

Either way. So, you're under the impression that Auto Manufacturers do not have input into the standards process for brake fluid.

Question: What is the Standards Body for Brake Fluid?

Answer: The SAE

Question: What does SAE stand for?

Dude, you should really quit while you're behind.

[cc9150]

<div class='quotetop'>QUOTE(wdross @ Apr 13 2007, 02:54 PM) [snapback]422862[/snapback]</div>

All car engines are designed for a specific octane rating to be used.
[/b]

But I wasn't referring to octane. I referred to the Top Tier gas standard as specified by Toyota, Honda, and BMW:

www.toptiergas.com

If you buy the cheapest brand (not octane rating), you get what you pay for. You probably pay more cents per mile to drive with the gas that costs the least to fill the tank. Why pay more cents per mile?

Use the gas that costs you the least per mile to run. It won't be grocery store or no-name gas.

[jrfaris]

<div class='quotetop'>QUOTE(Tempus @ Apr 13 2007, 06:47 PM) [snapback]423070[/snapback]</div>

Dude, you should really quit while you're behind.
[/b]

Is this a competition? I thought we were just discussing gas quality. It just seems curious to me that an ad hoc group of auto makers decide to establish there own "standard" rather than working through an established organization of engineers (such as SAE) to develop a universal standard.

[Tempus]

<div class='quotetop'>QUOTE(jrfaris @ Apr 13 2007, 10:41 PM) [snapback]423098[/snapback]</div>

Is this a competition? I thought we were just discussing gas quality. It just seems curious to me that an ad hoc group of auto makers decide to establish there own "standard" rather than working through an established organization of engineers (such as SAE) to develop a universal standard.
[/b]

Ah, now that's a good question.

I don't have a definitive answer for that, but I do know how standards bodies work, and we can make some informed speculation about the inner competition that's likely going on here.

Just as ISO and IEEE have different agendas based on the makeup of their members and consituents, it seems logical that other such differences of opinion may exist in other standards arenas.

We've already seen that the Auto Makers (via the SAE), set standards in many automotive areas.

Now, who sets standards for most Petroleum Products (Hint, the initials are API).

It seems probable that the members of the API might have a different agenda from the members of the SAE. The API members are the same ones that tell us that 'Premium' gas is better because it 'cleans engines' better. Of course that's a crock, and is indeed a 'marketing ploy'.

In the final analysis, of course, neither the SAE or the API really get to set the final 'official' standard with out Regulatory Authority. Each area of industry has a Regulatory Agency, and in the case of Automobiles, it would be DOT.

So, if an Industry group has a standard that makes sense, it can get a further boost by getting a Regulatory Blessing. The Regulators though generally just rubber stamp the industry developed standards. That's why you see Regulations that say things like "SAE Standard XXX is hereby adopted as DOT Standard XXX". The government really doesn't have the money to develop and maintain standards, the industries do, so it's symbiotic.

But, someone has to wrassle all the various standards groups into line. In the US this role has fallen to ANSI. You can think of ANSI as the "Godfather" of US Standards. In fact though, its more like a "Council" where the "Families" can get together and work out their differences without having a war.

If all goes well, your can of Oil will list API, SAE, DOT, and maybe even JASO (Japanese Auto Standards) or ILSAC (International Lubrication Standards) compliance.

But, what if SAE and API disagree? What if SAE believes there needs to be a standard and API doesn't want one?

The standards arena is really a good old boy network, and "Standards Potatoes" (All Hail Vinton Cerf!) aren't going to piss in each other's cheerios.

So what's an industry to do? If the Auto Manufacturers believe that there needs to be a standard for gasoline, and that crap gasoline is prematurely killing cars, killing emissions equipment, killing mileage and increasing pollution, what can they do?

The time honored approach is "Voluntary Standards". You go to the manufacturers, and sell them on the benefit of complying with the standard.

I believe that's what we're seeing here.

In my opinion, the Auto Manufacturers have the best insight into what's best for cars. No one has more incentive than them to avoid things like engine sludge and clogged injectors.

They also have a history of 'poking' the standards bodies with their own sudies and data.

As an example I present the "SA vs SL" oil wars.

Just like gasoline, oil with the proper additives is better for cars. The path to better oil does not always run smooth though.

I have attached an example of the types of research Auto Manufacturers develop and present in favor of standards that benefit cars.

We're seeing exactly the same thing now with gasoline. The studies and research all back the manufacturers.

You can decide whether they are 'just' looking out for themselves, or whether perhaps they are also representing the automotive consumer in this ongoing tug of war over 'standards'.

Even if you decide that the motives of the Auto Manufacturers are totally impure and mercenary, and the API is no better, you still have a choice to make. I suggest that your best choice would be to take the recommendations of the Auto Manufacturers. They are fighting for things that are good for cars. Wonder who the API is fighting for?

Look at the document I attached. You can go to the store and buy different types of oil. But, the Auto Manufacturers recommend a certain minimum quality in modern cars.

You can go to the store and by different types of gasoline. But, the Auto Manufacturers recommend a certain minimum quality in modern cars.

I doubt after reading that document that you'd knowingly put SA grade oil in your Prius. Being a smart consumer you'd probably want at least SL grade and if you could find SM grade you'd go for it.

Gasoline quality does affect cars. But, how do you know when you're getting "SL" quality gasoline and "SA" quality gasoline.

The current 'official' minimum gasoline detergent standards are the equivalent of the SA oil. They were developed long ago in a different era. The only way you can KNOW you are getting the "SL" grade gasoline is by buying from a manufacturer who adheres to the standard. If you don't you are getting a minimum of "SA" Grade gasoline, but that's all you're sure of.

You pays your money an you takes your chances, but your chances are much better with "Top Tier" gas at the moment.