What grade gasoline do you use

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

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.

 

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

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.

 

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

 

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

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.

 

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.

 

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

 

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

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.

 

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

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.

 

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

 

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

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.

 

<div class='quotetop'>QUOTE(Sunnyvale Prius @ Apr 13 2007, 06:43 AM) [snapback]422507[/snapback]</div>

:lol: :lol: :lol: :lol: :lol: I love how this subject gets most people fired up!,Its just a difference of $1.51 per fill up between REGULAR and PREMIUM. or just 20 cents more per gallon.

besides the owners manual states minimum octane rating of 87 OR HIGHER......not octane rating of ONLY 87.

also, I thought (i'm sure I will be corrected if I am wrong) that the higher the octane the better the engine performed under high stress driving. I am not easy on the Prius nor am I on any car. this should help the engines resistance to "knock".(period)

 

My concern with higher octane is the amount of fuel being burnt completely. If you can reach stoichiometric combustion with 87 octane then going to a higher octane and lossing perfect stoichiometry is not beneficial to your wallet or the environment or anyones health since that unburned fuel is just coming out your tailpipe. This could also reduce the lifespan of your catalytic converter. The same can be said for flooring the gas pedal often because when the engine revs up the air/fuel ratio drops which means your efficiency drops and you pass unburned fuel through the system.

This is based on a normal vehicle so I'm not 100% sure if anything is different in regards to a Prius.

 

Top tier gasoline is simply a standard for the composition of the gas (which nearly all US gasoline meets) and the type and level of detergent additives:

From http://www.toptiergas.com/

More on the specifics on their page at http://www.toptiergas.com/deposit_control.html

 

<div class='quotetop'>QUOTE(TomorrowMatters @ Apr 14 2007, 07:46 AM) [snapback]423189[/snapback]</div>

It might help if you had a more complete view of what is going on in the engine.

Octane is a measure of how resistant to ignition a fuel is. Higher octane fuels are harder to ignite, and lower octane fuels are easier to ignite.

Engines are designed with a particular compression and timing, with the goal being that the fuel will be in its most flammable mixture at the very moment the spark ignites it. The more precisely tuned this is, the better the engine will run, generating more power, with fewer emissions.

As the fuel is injected into a compressing cylinder, it heats up. In a diesel engine, this heat alone ignites the fuel. In a gasoline engine, this heat must prepare the fuel so it is ready to be ignited by a small spark. You can think of diesel fuel as REALLY high octane gasoline. It needs a LOT of heat and compression to ignite.

If your octane is too low, your fuel is too flammable, and it may ignite BEFORE the spark goes off. This results in knocking, or pre-ignition. It is both bad for your engine, and bad for your power and emissions.

If your octane is too high, your fuel may not fully burn, which can result in higher emissions.

Race cars often need high octane fuel. NOT because they are running the engine 'harder', but because they are using higher compression ratios, and more advanced timing to get the most power out of a given engine displacement. Unfortunately, this has given people the impression that the fuel has something to do with the power, or abilities of the engine to perform under stress. The fuel is just being chosen based on the time of ignition.

I've got a friend who runs a successful motorcycle racing team, small displacement class. They run 85 octane in their engines, since he builds them low compression, long throw. Its just his technique. Higher octane does not equal higher performance, or better performance under stress. Its all about the engine design.

When you choose a higher octane fuel, the ONLY thing you are changing is the timing of the engine. In small ranges, this doesn't change much, if anything. If you go too far off, your engine will suffer. It is worse to go too low than it is to go too high, so they specify a minimum. But specifying a max would be nice too.

And finally, the "If you can afford the car, you should be able to afford the gas" quote someone else dropped is exactly what the auto makers want to hear. Mercedes repackages FEBI suspension fluid, and charges twice as much for it. People actually buy it, knowing full well that it is the same stuff, because "they should be able to afford it, since they are Mercedes owners, after all."

Its like in the movie The Iron Monkey, when the doctor is treating two patients, one poor, and one rich. He gives the poor man his medicine, and charges him very little. Then he gives the rich man HIS medicine, and charges him 10 times as much. The rich man protests, to which the doctor replies, "Well, you are a rich man, so you need rich man's medicine. You wouldn't want to be using poor man's medicine... would you?" "NO no, of course not! I'm rich, I can afford the rich man's medicine! I'll take that!"

-Sam

 

87 octane, unless they are out of it, then no choice but to use the more expensive stuff. And I'm not sure why but my car always gets better gas milage on Phillips 66's gas. It's less expensive too.

 

<div class='quotetop'>QUOTE(jrfaris @ Apr 13 2007, 02:21 PM) [snapback]422882[/snapback]</div>

I agree that it is a lot of work/effort to determine the best gas. I tried regular(toyota reccomendation) and Premium. also did a short study using $/mile. Nothing much to really report. However, in this area, I filled with a tank of Exxon and it appeared to be getting more mileage 56 on same conditions instead of 52. I have gone back and forth a couple of times and the results seem to always be the same. the Exxon definately gets better. I know there are summer and winter blends, so maybe there is something in the blend. My Prius also loses 4 to 5 MPG in COLD weather, but I allow warm-up b4 driving. Wish there was som practical way to determine the amount of energy in a specific (Wallmart/Exxon)gallon of gas. More ENERGY= more MPG (in theory) B)

 

I run 103 Octane Jet-A race fuel in my Prius- I believe that accounts for the 400 HP output of the engine. I was going to supercharge it and then I stumbled on the 103 Octane trick. Man what a differrence and for only about $10 per gallon........
Come on now- I run 87 octane and always will. The car was designed for that grade of gas. Why not just flush $2 down the toilet every time you fill up with Premium grade? Same thing really.

 

I must be the cheap-nice person heretic in the group then. 87 only, and whoever is selling it cheapest. This often means Costco.

I did the exact same thing with my Accord. No engine troubles over a 6-year period. It developed some kind of fault where it'd unlock and lock the doors by itself while I was driving, but I don't think anyone here can argue that that's caused by gasoline additives.

In the end, it's really up to you. As I mentioned earlier, this brand pricing of gasoline seems to happen only down in the US; in Canada (or at least the western bits of it), I find everyone in a small region sells gas at the same price.

 

<div class='quotetop'>QUOTE(zqfmbg @ Apr 22 2007, 12:33 PM) [snapback]427906[/snapback]</div>

Kind of related, I guess, but has the Prius been subject to any of the "sludge" issues that Toyota's used to get? Our '98 Sienna van had sludge, and while this is probably not the official version, the service manager at our dealership told us it may have been due to cheap gasoline. GM and Toyota both had problems with sludge in engines, and I suspect that perhaps their "Top Tier Gasoline" recommendation was just a defensive move on their part. I see where Toyota is settling the class action lawsuit regarding sludge (I sure wish I could get my $800 back!)