timoc42

6 months old huh....lets try some really old threads and resuscitate them back to life...

joegolf68

Ok. we can bump the thread.

RAristo

Always premium on my Lexus and Toyota.

sha4000

iTrader: (1)

premium for the most part b/c any time i put in a lesser grade my MPG goes way down

joegolf68

Ok, the really critical answer to me is, for those who use mid-grade of low octane, what have you seen with performance? I'd love to hear from someone who has used a lower grade for several years and hear the results. I use premium and was told that if I bought low grade and added an octane additive I would save money and get even better results, I didn't bite as I really just don't know and why should I risk my car to save a few bucks? I only have 25K miles on a 2002 so am looking to sell and would like to have a perfect car to sell so when I get the 2007, if it is TRULY improved, I know I have sold someone a great car that won't have problems years later. I wish I could find cars as good a shape as I see them........ hmmmm.. maybe I should just drive them to the ground but I can't stand not having the latest toy.

Off subject, but in other posts they are talking about the new LS but looks like it might be the gs instead, don't know. If Lexus wants me to upgrade, they better put in some more toys and change the ugly box style they have now, otherwise, I can drive this thing for ten more years!

RA40

iTrader: (6)

Yup.

seatac

Premium

Bane

If the engine was designed for 91 octane, use 91 octane. Simple as that.

If you think about it from a monetary standpoint... Midgrade is usually ~10 centers cheaper per gallon. if you put 20 gallons of fuel in at each fillup (which is quite a lot) then you save a whopping $2.

No offense, but if you own an LS430 and you can' afford $2 extra each fillup something is wrong. Even if you put 20 gallons of gas in your car a WEEK that's still only $104 at the end of the year. You'd end up spending that taking the wife to a nice dinner... so just cut out one fancy dinner a year and use premium

rjm

I bought a new LS430 2 months ago. I asked the dealer if it would be OK to use mid-grade (89 octane) fuel in the car and he said my car had been filled up with regular (87 octane) fuel and that is all they have ever put in any car on their lot. He said the car will run great on regular 87 octane fuel. I have been using 87 octane and it runs fine. On a 1600 road trip (all interstate highways) I averaged 27 mpg and never have experienced any pinging or lack of power or performance whatsoever. Ed Wallace, who has the most popular automotive radio show in the southwest, says that any car manufactured since the mid-80's will run fine on regular octane fuel. The computers adjust for 87 octane just fine with no harm whatsoever to the engine. 91 octane is recommended in the manual because that is what is used in the horsepower ratings. By using 87 octane, you will lose a couple of horsepower but not enough to ever notice it. I have used 87 octane in Mercedes, BMW's, and Lexus' with no problems whatsoever.

campisi

I use (and have always used) 87 in my 03 LS430. No problems with pinging but I don't drive it like I stole it If I was interested in drag racing it then I'd put 91 in.

440+6

That wouldn't save you anything it would cost more, not to mention screwing up your whole car, and not passing emissions inspection. Because all octane boosters contain lead in the form of something called techtrablahblah. These cars are designed to use a specific octane, use premium only, the only one who benefits is the gas station because now youre paying for more gasoline that is lost from using a lower octane.

joegolf68

Feel free to reread my post..

joegolf68

Ah, finally a coherent answer, thanks.

For those who say, I it says use 91 so case closed, I love the faith! Like when floppy disks use to be expensive and they had 440k and 800k. I saved more than half by simply removing the tab on the floppy. Folks use to say, oh my, you can't do that, it just won't work as well. I used them for five years or so and saved a few bucks. I don't want to be a lemming or pay just to pay. I guess if one leases one of these cars, or plans a resell every few years, premium is an avoidable cost. I will continue to use 91 as I just don't think there is long term evidence proving anything one way or the other, and the cost is not an issue for me, yet.

PVSLS400

What about elevation i am at 5300 ft and was told by a rep of a toyota delearship that at this elevation 91 does nothing so save 20 cents a gallon is this true????

vicpai

...as MOST salesmen, is talking a whole load of BS. These guys are not engineers, and 99% of the time, many of us customers know A WHOLE LOT more than these salespeople

Now, here's the truth: If your car is NOT designed to take advantage of 91 Octane fuel, it will not matter one bit. You're just throwing money out the window (maybe even reducing the car's overall performance, since the ECU has to alter the timing)

OTOH, if your car is designed for 91Octane, there will be a performance difference (by which I don't mean just hp, but fuel economy as well)....and could even affect the overall longevity of the engine. The knock sensor is designed to retard timing, to prevent detonation, but this is not "normal" operation. So if it operates this way for a prolonged, continous period of time, who knows what effect it might have on long-term durability. So it is STUPID in my opinion to use "regular" to save the 16 cents a gallon. Besides this, like some posters mentioned above, the reduced fuel economy will probably cost you more in terms of dollars. Now, in this particular case, contradictory to what your salesman said, there will be an even greater difference at 5300 feet than at sea level, because the reduced TORQUE output by using 87 Octane fuel, will be even more apparent because the engine has to make do with much less denser air at the higher altitudes.