alextv

I recently purchased a 2001 LS430 and the salesman told me that he knows of several people that use the middle grade of gas. My question is how that will effect the gas mileage and or the power. Please post any experiences deviating away from the hitest gas. Thanks

DaveGS4

iTrader: (2)

Alex,

Welcome to ClubLexus!. One of the best features of our forum is the 'search' button up top.... many of the questions you might ask have already been discussed (sometimes several times) and you can get some great insight immediately.

For example, the premium vs mid gas topic, here are just a few threads I found right away by searching for 'premium gas':

https://www.clublexus.com/forums/sho...ht=premium+gas

https://www.clublexus.com/forums/sho...ht=premium+gas

https://www.clublexus.com/forums/sho...ht=premium+gas

https://www.clublexus.com/forums/sho...ht=premium+gas

https://www.clublexus.com/forums/sho...ht=premium+gas

https://www.clublexus.com/forums/sho...ht=premium+gas


Not sure where in NC you are, but check the Regional forums. We have meets pretty regularly in Charlotte and you're welcome to join us. The next one is a detailing 101 class sponsored by Zaino.

nthach

i ran 87 and 89 in my LS400, i had some slight knocking, but that went away. But there was a noticeable loss, the engine wasn't as smooth as it was with 91.

daryll40

I've posted this before, but here again is what I do since I HATE to pay for gas....yet I'll spend $60,000 for a car. Go figure. I am psycho!

Midgrade is 89 octane most places. Not quite enough. Hightest is 93 octane...too much. So what I do is mix 87 octane and 93 octane to get 90 octane which is close enough to 91 that the book recommends. In the end, the price is exactly the same as midgrade but you get a little more octane for the same money. The "cost" is that it requires two transactions at each fill up and, accordingly, takes about 1 minute longer. I've gotten so used to doing it that I don't even think about it any more.

The tank holds 22 gallons. Each 1/4 tank is 5.5 gallons. The fuel gauge is very very accurate. If I am down to half a tank, I put in 5 gallons of 87 octane then the rest (about 6 gallons) of 93 octane so the mix is tilted a notch higher than 90 octane. At 3/4 down, you need 16.5 gallons or 8.25 gallons of each, again tilted toward the higher. In "tilting", I buy a slightly "rounded down" amount of the 87 octane first, being careful to stop at exactly the number of gallons I calculate. I then just fill up to the brim with 93.

Probably I save $50/year doing this. Insanity I know. But it makes me FEEL like I am squeezing some value out of those crooks who supply our habit...er...our oil.

Daryll40

Pagong

does this work for people who live in California? since they have the pee like 91 octane instead of 93 that the others are getting?


Since I live in Washington state I am lucky to have 93 octane at the pump, but at 1.91 / gallon I will pass and just mix grades like what daryl said.

Beowulf

Sorry, but I disagree with the penny-pinchers. We're blessed with incredibly cheap gas compared to the rest of the world and you want to save $50/year by cheaping out on the fuel??? Everyone's entitled to their own opinion, but I believe in doing all that I can to maximize the quality of my stewardship. The last thing I want to hear is engine knock, especially from this car!

Some day I'll be able to pass it on to someone else, confident that the vehicle was always maintained at or better than manufacturer recommendations. Gas is cheap here in the Atlanta area - I don't quibble about the price for premium. Even if it weren't, I'd still opt for a premium fuel diet for my LS.

'04 LS 430 Black Onyx/Champagne, Modern Luxury, Smart Access, Preferred Accessory Package

buttons

Sir Robert Cotton:
agree that you do have cheap gas in Ga.--can't wait to cross the state line when I travel to GA. last I bought was $1.38 and that was premium !!!! in Dec 2003.

Pagong

Good thing I have an old model LS 1990 to be exact. But I never have put any other fuel other than premium in this car. I just wanted to know if the newer cars have less timing pulled on them because of the poor octane that they have...(Cali).

And on a side note, I think this is why some of these guys afford such a high dollar car, cuz they are cheap when it comes to gas...LoL...

daryll40

You are absolutely right. While squeezing buffaloes so that I save $50/yr on gas may, indeed, be somewhat psycho, it's that same "accumulation mentality" that has allowed me to be as financially strong as I am at age 44. Read "THE MILLIONAIRE NEXT DOOR"...that's me. Except for the $60,000 Lexus.

And I would argue that I am not at all doing anything "wrong". The car calls for 91 octane and that's exactly what I'm putting in. I am willing to work (mix 87 and 93) to get that 91 octane (a little over 90 octane, really, but close enough) at 89 prices.

By the way, 89 octane gas is absolutely the biggest oil rip-off. They do what I do with the mix tilted more toward 87 octane, yet charge exactly half way in the middle. Yet 89 octane is not halfway between 87 and 93.

As to California...I have no clue. California is a whole 'nuther culture and country when it comes to motoring. I guess out there you just have to pony up for the 91 octane that they sell as the top octane.

Daryll40, The Millionaire Next Door, Except For My Lexus

Pianoman72

daryll40, you are crazy like a fox. I like the way you think.

daryll40

massshelti

You should do a test. Run the car on 89, and keep track of mileage. Do this for a couple of months. Switch to 93. See what happens to the mileage. The additional octane might allow the computer to adjust the fuel mix to use less gasoline.

Has anyone tried this?

alextv

Thank you for the responses to my question. I am new to the group and did do a search after I posted my question and got varying views on the subject. I think the one that sticks out the most is the person that drove 2500 miles and tested the three different grades of gas. His experience was as high as 28 with hitest and as low as 23 with regular with the middle grade in the middle. Daryl has the solution if you want to go to the trouble of pumping twice. By the way I am as cost conscious as he is and agree with him that controlling expenses is the way to accomplish wealth as I am 56 and would not now own a LS430 if I had not done similar things. Thanks again for your responses and look forward to be active in the club.

daryll40

You'll get used to pumping twice. It's just not a big deal, really. One problem that does occur is that some pumps won't accept your credit card a second time. I have a debit card from my checking account that I use for the 87 octane and put the 93 on my credit card so as to avoid that problem.

As to having an "accumulation mentality"....just because you have money doesn't mean you have to be stupid with it. I would argue that even owning an LS430 falls into the category of "a luxury, but at least it's a QUALITY luxury". In other words, it still a "value" within the luxury category.

Daryll40, Valueman

SeattleGS400

iTrader: (1)

A while back, I spent some time reading up on the different octane grades--I don't have the original article by a gas company chemical engineer. But to summarize, here's what it mentioned:

1. Regular unleaded (octane 87) and mid-grade unleaded (octane 89) use a entry-grade of gas base stock. The difference between octane 87 and 89, is that octane 89 has a higher content of the octane chemical. All base gases contain variable percentages of heptane, septane, octane, nonane, dodecane, etc. but it's the octane that is the anti-knock index number. Quality in the entry-level base stock is supposedly quite variable in its chemical gas content.

2. Premium gas (octane 91+) is made from a premium base stock. All gas companies, whether they be Chevron, Texaco, Shell, Phillips 76, etc. use this very high quality base gas stock. It's like the regular base stock is tap water, while the premium base stock is more like distilled water--a more pure form. This premium base stock is different from the regular and mid-grade base stock, and is supposedly inherently much cleaner burning than the regular base stocks. All-in-all, premium gas from the different petrol companies is essenitally the same premium base stock, except for the proprietary additives the invidual petrolelum companies add. Further, based on geographical limitations and shortages, the oil companies even buy premium base stocks from each other--i.e. Chevron is temporarily short in say Seattle, so they buy from Seattle Shell's refinery some of their premium base stock to ship to Chevron's refinery to make their own version of premium gas by adding their proprietary additives. Lastly, ever wonder why the really cheap gas stations don't sell premium? They don't want to fork up for the expensive gas with the better, premium base stock.

Lower octane levels in gas is easier to ignite than higher octane. You want controlled gas combustion at the precise time--if it ignites before or after it's supposed to during the piston movement, it will rob your car of power and efficiency--so having the proper anti-knock index (aka octane rating) is optimal. Some lower compression engines are designed to run on 87octane gas, and they won't do any better with octane 89 or 92 gas--it's just that you'll pay more for the same performance. However, for higher compression engines that are designed to run on octane 91 gas, if you run say octane 87 or 89, the gas is more combustible and can cause engine knocking--the gas ignites at the wrong time--which isn't good (robs of effiecincy and power). To compensate for the knocking, the engines computer will detct the knocking and will change the spark timings, but will cause you to get a lower power output. That's the reason why you CAN run lower octane in your car when premium is not avaiable, but it's probably not good for the car running in a retarded spark timing state in the long-run.

Basically, my interpretation is this:

IF YOUR CAR CALLS FOR PREMIUM FUEL: Use premium fuel, and your car will run cleaner, more powerful and get better gas mileage than on lower grades of gas.

IF YOUR CAR CALLS FOR REGULAR FUEL: I'd use the regular fuel for proper operation. While you could use mid-grade and premium gas, the car's engine design will NOT take advantage of the higher anti-knock index of the fuel, and you'll just be burning more costly gas that you really didn't need.

Side note exception: I've also read that if your regular-gas car has higher mileage (say over 80K), it's sometimes beneficial to use a mid-grade gas to get better efficiency (with higher mileage, accumulated deposits on the internal components can lead to improper combustion). Try it out sometime.

If I find the original article on the above ideas, I'll post it.