Octane Rating
 

We've talked about it repeatedly...I'm a "Regular" guy. ;)

I'll be a "regular" guy:D very soon

I've always found it interesting that some people prefer lower octane fuels when the difference in price is usually less than $1.50 a tank fillup. And I also find it interesting that a good percentage of these people smoke cigarettes and are willing to throw $2.50 or more away a day on cigs that go up in smoke!

I can understand if moneys tight, every little bit helps....but I'd be willing to bet that the vast majority of people who put regular fuel in their vehicles do not take it slow off of stop lights with gradual increase in speed to conserve fuel, never drive over 55mph and never let their vehicles idle for more than 3 minutes.

Hey, this is just my opinion, it's neither right or wrong, good or bad. Just somethings that I have observed over the years. If you wish to comment on or rebute what I said, that's fine. State your opinion, but you don't have to add chopping my opinion up into to little pieces to make your point. That way your opinion can be respected also.:cool:

The Lexus RX 300 owner's manual states:

Select Octane Rating 87 or higher. For improved vehicle performance, the use of premium unleaded gasoline with an Octane Rating of 91 or higher is recommended.

Uh huh!
 

additude,
I agree. Don't smoke. Fill your RX up with premium. Words to live by my man, words to live by.;)

attitude, I will say this... your moniker is accurate! :D

Anyway, I put the best fuel I can buy because as you said a couple dollars per fillup is not going to break me. I'm sure I wont even miss the extra $75-$100/yr.

And I enjoy a nice tasty cigar as much as the next guy... haha!... I'm thinking about getting baby seal skin hubcaps, eating some raw beef right off the cow and driving really slow in the ultra fast lane.. I'm an a-hole--eoeo...

:rolleyes: :D :rolleyes: :D

Yeah, okay. Truth be known, I also enjoy the occasional puff... But if it meant lowering the fuel quality I put in my RX to be able to afford it, the puffin' would be the first thing to go.
I agree about not missin the extra $75-$100 annually that it takes to run your RX on premium - it's like being the owner/manager of a prize fighter and feeding him fast food all day long - yeah, it might be the cheaper alternative, but wouldn't you get more bang for the buck if you spent a little more and fed him a proper diet?
Alright, that was lame. Just fill it with premium already.
(oh yeah, Premium also cleans carbon deposits off your fuel injectors, so even if you dont' regularly use premium, it'd be a good idea to at least use it every 4th tank or so)

Prove it. :D

I use the best there is for my RX. It's called 87 octane. Any thing more is throwing your money away.

In the words of Daddy-O, Prove it. :D

CK,

You ask for proof when you choose to provide none?

That every 4th tank line is straight from an Amoco TV commercial. An oil company that wants people to spend more money has you quoting their advertisement. Madison Avenue succeeds again.

See the blurb about Amoco below.

87 Octane is the recommended fuel for the RX. It's not the fast food of gasolines. It's not the cheaper alternative. It's recommended by Lexus.

Higher octane gasoline did reduce engine knock in older engines that used carburetors to regulate the air/gas mix. The older engines could not regulate the air/fuel mix going into the engine as efficiently as a computerized fuel injector. A carburetor in need of adjustment could cause too much fuel to be mixed with the air, which meant the gasoline would not burn completely. The excess gas soaked into carbon deposits and caused a premature ignition of the gasoline from the heat of the engine cylinder. The premature ignition made a sound that came to be known as 'engine knock.' When this happened, people would change to the higher octane/slower burning gasoline to resist the premature burn, thus minimizing the knock. Upping the octane was beneficial then, but engines and gasoline formulations changed.

Over the last 20 years, engines use fuel injectors with computers to accurately control the air/fuel mix over all temperature and environment ranges. The accuracy of the fuel injectors and computers is based on using the recommended gasoline for that engine. Most cars are designed to burn regular unleaded gas with an octane rating of 87. The recommended gasoline for most cars, including the RX 300, is regular 87 octane.

One common misconception is that higher octane gasoline contains more cleaning additives than lower octane gas.

Please note this fact: All octane grades of all brands of gasoline, by law, contain engine cleaning detergent additives to protect against engine/valve/injector deposit build-up.

http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm

http://theserviceadvisor.com/octane.htm

http://www.auto123.com/en/info/colum....spy?artid=590

Six years ago, Amoco Oil has agreed not to make any performance or environmental benefit claim for any of its gasolines without first having scientific evidence to back it up.
http://www.ftc.gov/opa/1996/9602/amoco.htm

Wow Daddy - you laid the smack down on me.
I was just playing, not looking to get lectured.

My "proof" is straight from a post you made in this very thread:

"The Lexus RX 300 owner's manual states:

Select Octane Rating 87 or higher. For improved vehicle performance, the use of premium unleaded gasoline with an Octane Rating of 91 or higher is recommended."

I call your attention to the part about 'improved engine performance when using an OR of 91 or higher.'

I'm not a victim of television advertising - I don't remember EVER seeing that commercial. I got that straight from one of the techs at Lexus that it would be a good idea and guideline to follow. So while he may be a victim of marketing, he also knows his stuff.

As further proof, one of my neighbors is a gas tanker driver - very educated about the differences between different grades of gas. He's a firm believer in the type difference in the type of detergents used in Premium versus Regular, as in his words they are 'more effective at removing carbon deposit build up than Regular gasoline.' He's a personal friend and has no vested interest in the type of gasoline I buy.

The info above may or may not be concrete enough to satisfy you, but for the extra $2 it costs me at the pump to fill up with Premium, I'm going to continue to do and it not spend another second researching this topic - at some point the law of dimishing returns comes into play with regard to spending too much time researching something like this. If I was really that concerned about gasoline price and fuel economy, I would've bought a hybrid and wouldn't have spent as much on my ride to begin with.

I don't mean to be rude - I'm just starting to find this topic a little silly and trivial. You say pohtateoh, I say patahtoe.

;)

Daddy-O. Thanks for providing the "proof" for my quote above. You said it a lot better than I could have.

Here is a link to a Car and Driver article on Octane.

Car and Driver Octane Evaluation

C&D: "Our tests confirm that for most cars there is no compelling reason to buy more expensive fuel than the factory recommends, as any performance gain realized will surely be far less than the percentage hike in price. "

Yes, fine. That's a function of both the priciples of "diminishing returns" and "diminishing marginal utility," whereas the benefit gained by going to the next level may not rise proportionately with the cost of going to that next level for SOME individuals.

No, the benefits of using premium may not increase proportionately with the financial cost of doing so, but that means nothing to me personally. If I can gain ANY benefit from using premium, for the EXTREMELY MARGINAL cost of using premium RELATIVE to the other expenditures in my life, I'm GOING to continue to use premium.

Daddy-O, your personal thresholds might be different from mine. I also place a monetary value on my time, and in this case the amount of time I have spent debating the issue has cost me more than anything. Let's just say I have more than reached my limit of "diminishing returns and marginal utility," but part of me still loves a good debate, and that's why I've posted one last set of comments here.

Good luck to all of you in your quest for truth about fuel grades!;)

Daddy-O,

The sentence in that article truly says what it does, but when reading the entire article, especially the paragraph the sentence is contained within, it references to the fact that if your car isn't designed to use Premium octane fuels, it will not benefit from it. Right out of the RX manual it states, "Select Octane Rating 87 or higher. For improved vehicle performance, the use of premium unleaded gasoline with an Octane Rating of 91 or higher is recommended."

Meaning that the RX is designed to take advantage of premium octane fuels because it will "improve vehicle performance" as stated in the RX manual. By using 87 octane fuels, you will experience a decrease in performance.

"Cheapskates burning regular in cars designed to run on premium fuel can expect to trim performance by about the same percent they save at the pump." This is a quote from the same paragraph in the article.

The conclusion is that a driver can burn any type of fuel they want in their vehicles, but on vehicles designed to take advantage of premium fuels, the use of a lower octane fuel will decrease performance by about the same difference in price of the two fuels.

You would have a valid argument if the RX were not capable of taking advantage of premium fuels.

To take it a step further, an increase in power and performance relates to less gas usage per mile of driving. If the vehicle has more power and better performance, then the driver is not going to need to "Give it more Gas" to accelerate from a full stop or during an accelerated pass, etc. so the cost differences are further minimized.

The RX 300 was designed to run on 87 Octane gasoline or higher.
If the manual said 91 Octane or higher, I wouldn't burn 87 Octane.

The price difference between regular and premium is currently 13% in my area.

Your logic would see my mileage drop 13% from 25mpg to 21.75mpg.
My 0-60 time would suffer 13% and move from 8.5 sec to 9.6 sec.

This has not happened. Not even close, bud.

This is going to be one of those topics where you're not going to change anybody else's mind about it by debating, as we've all formed our own opinions based upon our butt dynos, statistical observation, and information that's available to the public.

I agree with some points, disagree with others, and finally in conclusion would like to say WHO GIVES A FLYING SQUIRREL?!!

Ya know, if we'd all put our heads together and try to find that answer to something truly useful like the solution to world hunger or elminating CWD from the deer herd we might truly have something.... but to me arguing over the type of fuel to put in your Lexus is starting to seem a little bit vein.

BTW, I'm going to use Premium for my RX each and EVERY time I fill up... and NOBODY is going to convince me that this is a BAD idea - I would much rather err on this side of the issue than the opposite.

It wasn't designed to run on 87 octane. It was designed to run on 91 or higher, however it can run on 87 octane, but there will be a drop in performance. That's what the manual says.

Quote:

---

The price difference between regular and premium is currently 13% in my area.

Your logic would see my mileage drop 13% from 25mpg to 21.75mpg.
My 0-60 time would suffer 13% and move from 8.5 sec to 9.6 sec.

---

That's not what I said, that's not my logic, that's what the professionals at Car and Driver said. I am quoting; not making a statement and you can bet I will take their word, their lab reports, and their test results with calibrated instrumentation over your "Feeling" any day without hesitation.

You can run 87 octane all you want. I don't care if you use diesel or what you do. I've made my point, which is validated on scientific evidence, certified test results as reported by professionals within the industry.

Quote:

---

This has not happened. Not even close, bud.

---

Prove it. Car and Driver did and made a statement to the fact.

I'm outta here; this is a ridiculous argument of evidence and fact against hearsay and baseless perception.

3 tanks regular then 1 tank premium.................

just because.............. i can't figure out what to do with the extra 2 bucks in change sitting in the RX at the end of the month

Well I guess I am just a cheapskate according to a previous post. But after running a regular vs. premium test on both my RXs, reading all the previous posts and other tests done, and reading the car and driver article I am convinced regular is the way to go.

Huh?
mikey, have your read the car and driver article?
have you read your owners manual?
have you read all the previous posts?
have you looked at all the other tests done?

If yes, then my feeling is the conclusion should be if the most important thing to you is saving a few bucks each year on gas, then Regular is for you. If you want the BEST POSSIBLE PERFORMANCE out of your RX and don't mind spending a few extra bucks to get it, then you'd want to go with PREMIUM - this is in accordance w/ the C&D tests and article, as well as your RX300 OWNERS MANUAL!!!
Sheesh, for me it's not even a matter of using Reg or Prem anymore, it's a matter of acurately interpreting the SOLID evidence and fact as Additude stated. If you are CHEAP, that's FINE... I know lots of cheap people out there and I call many of them friends. But com'on, for the extra $$$ involved in using Premium vs. Regular, the only argument against using Premium is that you're being cheap. Even the friggin owners manual tells you to use 91 octane or better for optimum performance.
If you're cheap, that's fine. There's nothing wrong with it. Just don't sit here and tell me that Regular gas is as good or better than Premium - you're just snowing yourself.

Yes, I have done all that and still say regular is the way to go. I would buy premium in a minute if I thought it provided any marginal benefit to me.

The manual states "Select Octane Rating 87 or higher. For improved vehicle performance, the use of premium unleaded gasoline with an Octane Rating of 91 or higher is recommended"...not "BEST POSSIBLE PERFORMANCE" or even "optimum".

C&D:"Our tests confirm that for most cars there is no compelling reason to buy more expensive fuel than the factory recommends, as any performance gain realized will surely be far less than the percentage hike in price. "

Look a the cars they tested: A 300hp BMW and Turbo Saab.
Both require Premium fuel right out of the facdtory. Look on their web sites Their fuel requirements are published.

Again, I'm not seeing a 13.8% gain. Again, not even close. I'm proving it everyday and have posted my results and mileage regularly in this forum for 5 months. I started with premium, switched to regular and now have switched back to premium in an experiment that I am currently in this forum.

This reminds me of all those BS political campaign ads you see on TV. They give you a small spin on a certain issue that just happens to support their angle/campaign platform.

Looking at the big picture based on all information available to me, I chose to vote for the Premium candidate because I feel the benefits of electing him outweigh the negative costs. You're a different voter and a different individual - does that mean I don't like you or even think you made the wrong decision for you? No way man - I'll still buy ya a beer after we vote! :D

I think most of the information for people to make their decision is right here in front of them on this thread, and the rest is in their own personal observations and own personal butt-dynos ;)
Any further debate is just starting to sound like mud-slinging, and we all know how petty and childish that sounds when "grown-up" politicians resort to those type of campaign tactics - makes you feel like you don't want to vote for either one of them regardless of their stances on the issues at hand.

At the risk of already having crossed that line, I'd like to propose leaving this topic as "agree to disagree," with both sides having presented their arguments to the fullest extent necessary for the educated voter to make the decision that is right for them. Just my .02 - God, didn't I say I was outta this a long time ago? I must be bored on a Friday...:rolleyes:

I guess that was hearsay and baseless perception. ;)

Yup, guilty. ;) BTW, it wasn't me who spoke those words originally - I'm more tactful than that!:cool:

For the record, I hear both sides points - I just don't wanna see this get ugly. If we're gonna spend a ton of time debating something about the RX, it might as well be how to turbocharge the VVT-i engine or install nitrous or something along those lines. Let's just say the utitlity of our debate has diminished :o

I'll fix it...Check the poll.

LMAO! Good one Daddy-O. I guess being the forum moderator has it's advantages eh?!! Wow, I didn't know the RX forum even had 819 users?! We've really grown!

Yes, behold the power of cheese!

That is exactly what it states.

It`s only designed for premium if it states;(premium unleaded fuel only)as per my 1987 Mercedes 300E stated.

Hey, CK1, when I want to know something about International Whifflebells, I always consult the truck driver who delivered them. Those guys always know everything about what they're tooling around the country. LOL. My '02 RX runs just fine on regular. It would run just fine on premium. It is not the couple of extra bucks premium costs me that bothers me, it is the many, many, extra bucks the industry gleans from we the people. I always used premium in my '97 Jag Vanden Plas 'cause Jag told me to in no uncertain terms. That engine may be the best 6 cylinder ever manufactured. We had other issues with the car (paint, headliner, mounts & bushings), but we spent zero dollars and zero cents in 7 years and 72K miles on the engine. Sort of reminded me of the old Dodge & Plymouth sixes from the early 60's. Oh, yeah, I'm no spring chicken. Enjoy your day, guys.

Yeah like the old bullet proof 255 slant six. Noisy engine,but ran,and ran.