Rx900

i wonder why in some countries(like the Philippines) have regular start at 93 and some premium at either 95 or 96? does that mean that the regular 93 is like "premium" here? i really dont know much about gasoline.

lilprince

I have an camry that i drive as my beater and when I put 87 in it I get 350 miles in a tank and if I put 91 I only get 275 Miles but you should put what they reccomend for the cars you drive if you put low octane like 87 for a car that should use 91 octane it will have a pre-detonation (ping) can could cause hot (hard) spot in the cylinder bore on the block

CVsIS250

Again, it is not pre-mixed

According to my buddy who is an engineer for Marathon Co., the pump pulls out of both tanks. They don't have three tanks in the ground...way too much space.

Only two types of fuels are delivered. The pump pulls out of either of them or both.

CV

trebien

A custodial engineer?





Typical gas stations in the past have 4 or 5 tanks.... each for the 3 grades of gasoline, and one for diesel (if they sell it) and sometimes a fifth for waste oil. When you drive into one, yo ucan see the little raised areas that are the fill-up points for the tanks. Each one is usually a different color for each grade.

Granted, times change and maybe this is a new policy or design, but typically, stations have a seperate tank for each grade of gasoline.

For instance, click here.

loflin

hmm, well I don't know 'nutt'n about it at all, except I did understand Trebien's original point (which we drifted away from), and to restate, that was, when you are doing mpg tests of different octanes, you need to do multiple tanks of each (preferably from different gas stations each), to have a valid sample, as with just one or two tanks, you MIGHT have got a fillup from an octane grade that was running a little higher than their label for that particular batch, Therefore the difference between your two octanes you are testing might not be much of anything.

But, back to the ongoing and exciting "discussion" on how many underground tanks at a gas station. Trebien, the diagram and link you post, really doesn't add proof one way or another, since, even though it's a "typical four tank" station, it is only showing 2 grades of gas. Look at the piping.

trebien

You're right, in that the primary point is to use mutiple samples.

It's hard to tell on the right hand side because of all the pipe crossover (they are crossing over each other, not connecting, in most instances), but the pumps at the bottom of the diagram are serviced as follows, from the left:

Pump 1 - 1st/second tanks (regular grade)
Pump 2 - 3rd tank (mid-grade)
Pump 3 - 1st/second tanks (regular grade)
Pump 4 - 4th tank (premium)


Possibly there are 2 tanks for regualr grade, because they sell more of that type than the others. But each pump only pulls from dedicated source tanks.

BobsGX

What I would like to know is when I pull up to a single handle fuel pump that delivers all 3 grades of fuel from one dispenser handle, and the previous purchaser used regular unleaded (87 octane) fuel, and I am purchasing premium unleaded fuel (93 octane), how much of the regular unleaded (87 octane) fuel will I get before I get the premium unleaded (93 octane) fuel?

Does anyone know for sure? Maybe someone who does repairs on these fuel dispensers would know. I've heard anywhere from 0 to a gallon before the proper fuel reaches the pump handle. Most of those fuel pump hoses are over 10 feet long so I imagine the hose holds quite a bit of fuel.

In other words, are we paying a premium octane fuel price even for the regular octane fuel that was left behind in the fuel fose from a previous buyer? If so, that isn't fair.

sayadil

On behalf of everyone i did a research on this.
first of all.. Putting in higher octane is a total waste of money. Higher octane fuel other then rectifying Premature Ignition (only incase on engine knocking to recommended octane level) doesn't do anything else. It doesn't even outperform regular in cleaning up ur car either.
here's the link to the federal trade commission website.. clearing things up for lot of us.
http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm

Other then that... Mid grade is obtained by just mixing higher octane 91 and lower octane 87. Its equal ratio of both fuels which gives mid grade octane level of 89 (1 above or down). ITS NOT PRE MIXED. (in case of Esso/EXON). So CVsGX470 was right about that.
Quote below is from edmonds.com regarding octane issues...

"Interestingly, Mazor noted that at some gas stations, there are only two grades of gas. However, they blend the regular and premium at the pump to produce the mid-grade gasoline. This allows them to have only two underground tanks for the gas storage."

Hope that clears lot of confusion.. so suggest putting in midgrade to everyone, putting in higher octane (then the manufaturer suggested) is giving more money to the gas stations.

trebien

Thanks, sayadil... more mis-information from the king himself... "on behalf of everyone".

Did you even read the first paragraph? Geez.

"...the recommended gasoline for most cars is regular octane. In fact, in most cases, using a higher octane gasoline than your owner's manual recommends offers absolutely no benefit. It won't make your car perform better, go faster, get better mileage or run cleaner. Your best bet: listen to your owner's manual."

What it says, is what many (and myself) have said... if the engine is designed (higher compression, increased timing) to take advantage of the higher octane, then you should use it. If not.... then it offers no benefit. The article doesn't say "everybody should use regular, and it's a total waste of money to use premium". That's a crock.

"...suggest putting in mid-grade to everyone." Bad advice, dude.

My uncle owned a commercial contruction company. I've seen many a gas station being built during summer jobs. Seperate tanks for the different grades... seen it with my own eyes. I'm not saying that it isn't possible that some stations use only 2 tanks and mix, and never did. But definitely, some don't.

I've also built 800+ HP race engines... so I know a thing or 2 about compression, timing, ignition advance, etc. and how a gasoline engine actually works.

Thirdly, NOT ALL GASOLINES HAVE THE SAME ADDITIVES IN THEM. BULL!!! What the article says, is that octane ALONE doesn't help with deposits. It's not talking about the different additives from each level or brand of gasoline, that are increasingly added to most gasolines, as you get into the "premium" octanes. There is a minimum deposit control (DC) additive requirement set forth by the EPA - the LAC level... but using more than the minimum helps things over the long term in reducing carbon buildups on injectors, valves, combustion chambers, etc.

Also, that article quoted above was published in 2003. As time goes on, more and more engines are using advanced timing and higher compression... so more and more are requiring the need for premium gasoline, due to the technology in them.

You can continue to argue all you want. It's quite ridiculous. And even worse, it's bad information that could cause damage to a vehicle, and long term expenses both in terms of mileage and durability.

Goodness gracious, people. PLEASE do your own research before taking this crap to heart. Any fool with a keyboard can disseminate information... or mis-information, as the case may be.

Despite trying to help, I'm done wasting my time.

trebien

BTW - moderators... please leave this response intact for the sake of people doing research now or in the future have valid and accurate information to reference. This type of erroneus information needs to be corrected. Thanks.

sayadil

Well first of all trebein.. i have seen ur response in most treads and it seems like u make fool of urself everywhere.. don't know why you take everything as a personal attack...
now let me clear few things up...



[I]"...the recommended gasoline for most cars is regular octane. In fact, in most cases, using a higher octane gasoline than your owner's manual recommends offers absolutely no benefit. It won't make your car perform better, go faster, get better mileage or run cleaner. Your best bet: listen to your owner's manual."

What it says, is what many (and myself) have said... if the engine is designed (higher compression, increased timing) to take advantage of the higher octane, then you should use it. If not.... then it offers no benefit. The article doesn't say "everybody should use regular, and it's a total waste of money to use premium". That's a crock. [/I]

It clearly says to follow owners manual.. which clearly states that GX engine is designed to handle 87 and above. putting in higher octane is a waste of money. Addictves can be added every now and then (STP $2-3 a bottle good till 8 times u fill up) so putting in higher octane in gx is a waste of money as it will not give you any other benefit. simple enough for you.

"...suggest putting in mid-grade to everyone." Bad advice, dude.
its the advice from the website itself (and several others) which says if your engine is designed for lower octane .. higher octane is a waste of money... and i'm sure noone except people like you wanna waste money .. specially on gas of all things which is going up n up .

My uncle owned a commercial contruction company. I've seen many a gas station being built during summer jobs. Seperate tanks for the different grades... seen it with my own eyes. I'm not saying that it isn't possible that some stations use only 2 tanks and mix, and never did. But definitely, some don't.

We honestly don't care about what ur uncle does or owns.. edmunds (a well reputed website) mentions MOST stations.. so for most pumps they mix it at the pump. unless you can tell us specifically what gas company sends PRE MIXED gas so that we know .i confirmed personaly with ESSO and they clearly explained that they only get two kinds of gas 87 and 91 and they mix the two. bigger stations have more storage tanks .. that doesn't mean anything.

I've also built 800+ HP race engines... so I know a thing or 2 about compression, timing, ignition advance, etc. and how a gasoline engine actually works.

whats the point ? by the way you talk, i can only imagine what kinda engines u design..
r u saying to put higher octane in GX .. we r only talking about GX here... so get to the point (if you have one) just coz u make engines doesnt mean u r more qualified then people who are working at fedral positions or techinicians working at lexus.

"Thirdly, NOT ALL GASOLINES HAVE THE SAME ADDITIVES IN THEM. BULL!!! What the article says, is that octane ALONE doesn't help with deposits. It's not talking about the different additives from each level or brand of gasoline, that are increasingly added to most gasolines, as you get into the "premium" octanes. There is a minimum deposit control (DC) additive requirement set forth by the EPA - the LAC level... but using more than the minimum helps things over the long term in reducing carbon buildups on injectors, valves, combustion chambers, etc.

where exactly did you read octane alone doesn't help with deposits.... and regardless.. putting in higher octane for the sake of addictves is as dumb as ur argument.

Also, that article quoted above was published in 2003. As time goes on, more and more engines are using advanced timing and higher compression... so more and more are requiring the need for premium gasoline, due to the technology in them.

we are not talking general terms on this forum.. we r talking about GX in specific and the technology advancement related to GX... as of now GX engine is still designed with 87 in mind so unless the owner manual tells you to put higher octane you don't have to... thats the bottom line.. doesn't matter what people like u say... its the fact and its been talked about on lot of informations websites like the FEDRAL WEBSITE I LINKED... not a confusing map which had nothing to proove.

Your wasting your time on this forum and misguiding people.. my point (as the title of the forum) was to tell people not to waste thier money putting in higher octane fuels rather then midgrade in GX 470. Whether you agree or not it doesn't make a diff.. i'm sure there are people who still rather put higher octane and then there r people who will understand that GX doesn't need higher octane fuel and for addictves they can always use products like STP once every few months. people can save hundereds of dollars by reading to the website.

trebien

sayadil - I'm not responding to you anymore, since I'm too busy making a fool of myself everywhere.

To be clear for everybody, so they can make their own choices. Just facts:

The GX470 gained an updated engine for the 2005 model year. All 2005 GXs and above have this new engine. It includes their VVT-i system, the Variable Valve Timing with Intelligence system... to better control timing and accomodate different grades of gas. It also increased the compression ratio from 9.6 to 10 to take advantage of higher octane fuels.

To quote the owners manual of a 2006 GX470:
To quote the sticker on the inside of the gas filler door:
Just for kicks, I stopped by 3 different gas stations today. An Exxon, Chevron and Shell. I asked them if they had seperate underground tanks for the mid-grade, and they all did.

There is no alignment adjustment whatsoever for the rear axle of the GX470.

Take care.

CVsIS250

Dude if you stopped at 3 different stations to ask about their tanks, you have absolutely too much time on your hands or you are full of doo doo. You poke fun at my buddy for being a "custodial engineer," but you rely on information about the structure of the pumping system from the guy who sells beer/coffee and smokes at your local BP. Give me a break...

sayadil is correct in his support of what I said before. Gas companies DO NOT pre mix mid grade. It would be a complete waste of time and resources. No matter how they mix (because I am not an engineer) they do so at the station. If my information about having only three tanks is wrong because you found a picture on the net of a set-up, I am sorry. However, I guarantee you that the extra tanks are for nothing more than storage of the amount a fuel they need to stay in business and have enough in supply. There is only 2 (3 or 4 if E85 or Diesel) types of fuel at the station.

YES, the GX calls for premium fuel. YES, we have beaten this subject dead. But, yes, sayadil is correct that you can run the GX on 87 forever and will not harm to the engine and you will change the mpg minimally. I use 93 because of the additives that clean your engine.

CV

The G Man

Can't we all just get along.

The turth of the matter is, if you own a 05 or 06 GX, using premium is not a total waste of money. It may be money not wisely spended in some people's opinion. You will notice some slight increase in power, the engine run quieter and smoother and a slight increase in gas mileage. Rather that justify into the extra $4 per tank full, thats entirely up to you.

CVsIS250

I agree...seems as if some here think that every disagreement is a personal attack.

CV