djct_watt

Nor is it true that all scientific facts are based on facts. . . controlled experiments are exactly that. . . in fact, if you are clever with statistics, samples can be skewed, results controlled, and data corrupted. The fact is that humans are involved in the process, and the results will always be prone to human error, purposeful or accidental.

That doesn't mean that science is all together worthless, it just means that "studies" and results should be taken with a skeptical eye.

Chikubi

^^^^ what he said.

Me, I was just trying to save time and headaches by posting the layman's version of this,http://www.faqs.org/faqs/autos/gasoline-faq/part1/, the Gas FAQ, which says essentially the exact same thing, but in nowhere near as succinct a fashion. I wouldn't have mentioned the Shell Oil FAQ at all if I thought it was just company hype.

SciFly

in my input on top page two i said that "glippy is entirely correct". No, I was sloppy to have said that. And Jethro, I did not advocate using higher octane fuel. You misunderstood me, but I did err first.

gslippy's page one boner is found in this misapprehension of what happens. What is KNOCK? it is not this, not quite, anyway:


Knock is the descriptive word of the sound of audible -detonation-

Detonation is of such violence as to make a rattle or knock by sheer shock to the metal of the combustion chamber surfaces. It matters not one bit even if all the mechanical parts are a-1 tight. The noise occurs just the same at detonation, which is a shock wave much as if it were a hammer strike.

It's all owing to a nearly instantaneous, all-at-once combustion

Detonation occurs for very specific reasons. A pioneer researcher in this field, Sir Harry Ricardo, discovered the cause, effect and means to vastly reduce detonation. I can quote interesting text from his classic and rare out of print book, The High Speed Internal Combustion Engine

Ricardo's importance in IC engine history cannot be overstated. His anti-detonation cylinder head design was considered to have swung the outcome of WW1 in our favor. The increase in engine effiency brought by the Ricardo Head saved much fuel and allowed higher power outputs for any given compression ratio or fuel employed. In those days there were not too many ways to increase octane rating. Most fuel was of an octane rating which today would measure out at 60 or so. This was before TEL as an anti-knock revolutionized engine design even further by knocking out the knock, very nearly completly.

snowromance

lol people see "premium" and they think its better. not realizing they are hurting their performance by not using what the engine was designed for. not the smartest bunch. it works the same with sportbikes from the people i know. their manuals say 87 just like mine but they only put in premium because they dont know anything about their bikes except for when they clean it its shiny

xBster

87 for me...I have tried the higher octane a couple of times...actually dropped my mileage a bit and didn't notice anything else that would warrant paying the extra $$ for it.

2Black2Box

I'm confused; since when did this post turn into an insulting stand up comedy show? I thought the question was "what type of fuel do you use?" Not "tell me how much money I'm loosing if I use 93."

I don’t understand how we got from “what do you use” to “CAN’T YOU READ?” How is it in any way considered a loss or a waste of money to one who believes that there is a performance boost in using higher octane, or one who sees it? A waste can only be determined by the person in the situation, and if that person doesn’t consider his/her decision to be a waste, then it is not.

Helpful information gentlemen; helpful information… I see a bunch of negative, bias a$$ opinions. That is negativity that we don’t need.

87 is the cheapest gas, but it is required for the Xb. It is also the same gas that is used to operate lawn equipment. I’ll take my chances in quality with a higher octane, thanks.

By the way, I use 89.

snowromance

sorry man but its not whatever someone believes is right for them like you said. its not about negativity. its about the masses of people that dont know anything about their engines and see "premium" and think that its better for their car. i mean i cant blame you guys the title would get me thinking too. But then you do some research about it and realize that you are being kinda dumb and wasting your money. not here to tell you how to spend your money just letting you know you are wasting it and looking foolish. keep doing what you do, if i owned a gas station i would want you wanting "premium" as well.

tell ya what jet fuel is what we use in 300 million dollar jets and is rather expensive. im gonna start taking my chances with that and put it in the xb because its obviously the people who designed the xb's engine are wrong in telling me to use 87 octane since honda lawn equipment runs on it too and that just cant be right.

2Black2Box

I understand your point. I'm just saying, I saw that someone asked another if they can read. Then I see people calling others stupid. Thanks to everyone for the advice, whether it is good or bad advice; but no thanks to the ones that HOLD the power call someone else stupid or dumb on an internet forum.

If some of you get a glimpse of the people here that are a healthy 300 lbs, I bet the reactions change from "your stupid" to "I'm just saying I wouldn't do that."

The internet puts golden gloves on the people who use it to insult others. Gloves that do not exist in person.

Instead of calling someone who doesn't know any better "stupid" you can post helpful facts that may change the way they look at it.

Me personally, I know all about what Toyota tells us to put in our car. It just seems as though I get better gas mileage when filling up with 89. Do I? I haven't done a scientific study on it, but it appears so.

You're a hell of a comedian with the jet fuel thing though...

Fusion-Ti

regular...with the amt of miles i put on, it saves a lot...plus, the extra octane doesn't really help..but if it makes you feel better using 93, go for it. Unless you're going FI, I don't think you really need the extra octane.

2Black2Box

93 is just too damn expensive to put in there for me. When I got a free gas ticket, I tried it out; but I didn't notice a difference that was good enough for me to continue punishing my pockets for the constant fill up.

SciFly

All that octane rating denotes is the fuel's resistance to detonation.

There is some anecdotal information (subjective opinions) stating stating that higher octane fuel burns more slowly. I can't say...

What can be said, is that fuel still burning late in the combustion cycle contributes no power to the engine, plus, burning mixture rushing past the exhaust valves will tend to burn, warp or otherwise shorten the life of the exhaust valves.

Aside from "I think" and "I've heard..." stories, the web surely offers first-hand scientific studies on this worn out topic.

Note that the SELLERS of gasoline -never- claim that higher octanes make low-octane engines run better. WHY? Probabably because they cannot make false claims.
Otherwise, if premium were great for low compression engines, the gasoline companies would be advertising for the 87 octane auto owners to "step on up to premium octanes for power! economy! action!"

but they don't...

jct

i use the cheap stuff 87 octane

SciFly

for humor!

Jet fuel is "more powerful" per gallon than gasoline.
It's high grade kerosene.
It's denser than gasoline; more energy per unit.

Too bad, these heavier fuels have abysmally low octane ratings--they cannot be used in compression engines--other than diesels, practically speaking.

vintage42

Scion says there is no benefit from any octane higher than 87:
------------------------
Scion Customer Experience Discussion Thread
Scion xB horsepower and torque [Incident: 060901-000071]
From: Scion <scion_mail@scion.com>
Response (Vernon) 09/06/2006 04:09 PM
… The vehicle is engineered and tested using 87 octane fuel. We recommend that fuel for optimum performance, reliability, and fuel economy on the vehicle. The vehicle does make the same power at maximum throttle position on 87 octane as it would on higher octane fuel.
-----------------------

biblicone

I drive around looking for the cheapest gas possible... hehe.

airdave

A statement that circulates around quite often is that all fuels are alike and come from the same place or refinery.

While this is somewhat true - all refineries share their BASE product with other companies - what sets the brand name companies apart is the additive package added at the rack when a given tanker truck loads the product for a specific station delivery, ie, Chevron, Texaco, etc. The additive packages includes higher percentages of detergents, injector cleaners, dispersant, etc. depending on the brand chosen. Without singling out a certain brand lets just say the price DOES reflect the quality of the fuels. While here in California we have a certain minimum spec on the additives used, the "majors" actually do add more additive percentage for better mileage and engine cleaniness/performance than the off brands.

So, that being said, the quality of the fuel you put in your car is certainly dependant on the brand.

I worked as a tanker driver and plant manager for 27 years and have come across this misconception more times than I can count from the uninformed general public.

mrfuzzy4

I'm a simple box owner with simple pleasures. 87 on the cheap. gas is gas, i'm not really into the whole conspiracy thing. I think all gas is just about the same - as low grade as possible. it's a business's product after all...

from what i read, no 93 won't really hurt your box, although some feel there might be a loss of hp, it seems unlikely. What's really under consideration is if it actually helps. Some say yes, some say no, some go ape on anyone with a different opinion. This is one of those topics that is best left alone, like politics. I would suggest only using an 89 if you wanted a higher fuel, but it's your money. plus 93?! you driving a lambo?! even premium cars only use 91.

SentraSE-R

IIRC, 22% of my fellow students in class got Ds and Fs for grades. That correlates well with the % who buy premium fuel for cars that gain no benefits from premium fuel.

There seem to be two types of people in the world. One type thinks logically, heeds the arguments, and buys regular fuel (for cars designed to run on regular fuel) based on a logical decision. The other type believes, on no rational basis, that premium fuel "can't hurt," or "might work," and buys it on faith and hope. The PT Barnums of the world live off of those gullibles. What's humorous is when the gullibles start insulting the rationals, as happened in this thread.

SentraSE-R

Good points, Dave. I've seen the same tanker leave a name brand station and go to an independent station, and v.v. In Alaska, we had just one refinery in the state, Tesoro, so all our base fuel came from the same source. I don't place a lot of faith in additive differences, since I've never had problems with fuel injectors gumming up, etc.

MadMike550

I use 93 in my 66 Mustang..and the cheap-o stuff in the B