best gasoline grade for rx 300
N & A S
I'm wondering what's the best type of gasoline? My salesman recommended
mid-grade, but it seems like the manual recommends hi-grade.
Anyone have any recommendations?
Atlantis
Follow the manual. Most Lexus' (if not all) require high octane fuel.
Manwe Sulimo
>
> Follow the manual. Most Lexus' (if not all) require high octane fuel.
>
>
"Require" is the word that caught my attention. This is not factually true.
Any lexus automobile (and most of today's engines) will work on a range of
fuels. You can put 87 octane in your RX300 and never have a problem. Most
engineers will tell you, though, that you will suffer a performance
decrease--the margin of decrease is where you get tempers flaring, though.
The engine is intelligent enough to adjust to variations in the fuel type
(sometimes higher or lower octane, sometimes the brand of gas varies
tremendously, sometimes just a bad tank of gas). You may get some pinging,
but even though will be drastically reduced to what it would have been some
years ago because of the time-fired reaction of the pistons. Most people
would say that your gas mileage would be affected as a result--again
opinions differ as to how much. If you find it to be a great difference,
then maybe using 91 makes economic senses.
The manuals does indeed say 91 octane, and if you want to guarantee the best
performance, put that octane in your vehicle. Many people might say (and
they have a point, though I am not sure I totally agree with them) that if
you are worried about the 20 cent difference between 87 and 91 you should
not be buying a Lexus--others would say it is all about not paying for what
you really do not need--like getting your oil changed at the Lexus dealer
instead of a local machanic who charges you half the price you would have
paid.
In the end, do not loose too much sleep over it. Also, be glad gas is
something like 80 cents cheaper around my parts than it was just a while
back.
JB
sort of problem like pinging or performance decreases... I think the whole
higher octane thing is a non-issue with the Lexus engine. It just adjusts.
Not true with my Surburban though. It pings with lo-test and develops
ore-ignition after a tank or two so I put half mid and half hi-test in it
and that solves the problem.
Rgds...Jim
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"Manwe Sulimo" <manwe-...@attbi.com> wrote in message
news:uDXY7.7874$Qe1.122405@rwcrnsc53...
Atlantis
I never meant for my comments to be taken to such extents... this isn't a
language/grammar newsgroup. I was referring to the fact that almost every
Lexus user manual for each Lexus vehicle would state the use of higher
octane fuel is needed.
True, modern engines use knock sensors to retard timing to enable the use of
lower grade fuels, but if you want to use the engine in the correct way it
was designed, following manufacturers recommendations is useful. Afterall,
they designed the engine, and the knock sensor is there for people who
disregard recommendations and complain if the car pings when they put cheap
fuel into it.
Manwe Sulimo
"Atlantis" <us...@domain.com> wrote in message
news:a134a5$1i3$1...@bugstomper.ihug.com.au...
To a point, I would agree with you Atlantis. But here are a couple of
things to consider: First, you have to tend to be rather specific when
posting to newsgroups these days. There are many intelligent people out
there, and if you are not specific the poster may get conflicting
advice--sometimes just because of the communication problem. You could
easily be recommending the same thing and start a huge flame war.
Second, just because certain engineers designed the thing, that does not
make them experts on how to deal with it day-in and day-out in everyday
life. Dell tells me not to treat my laptop in certain ways, but I do
because that is what my work/use requires. Dell is just playing it
safe--but they do engineer their laptops to take a lot of pounding.
Third, it is not necessarily the engineers who designed the engine who are
writing the manual. The engineers could very well have designed an engine
whichs adjusts to the degree that you will never feel a performance/gas
mileage decrease (many people think this is exactly what they have done,
though I am not sure the simple chemistry/physics would quite agree). But
the manual writers--who may be influenced by many departments at Lexus like
legal, etc.--may think that putting "use 91 octane" is the "safest" bet all
around. And it probably is.
Fourth, some conspiracy theorists believe that the "requirement" for the
higher octanes is just a kickback to the oil dealers/manufactures. Just a
way to increase profits for the whole industry at the consumer's expense. I
find this reasoning less convincing than the others (there seem to be too
many oil manufactors for this to work in a simple way), but that does not
mean it does not happen. I personally have always wondered why GM,
Daimler-Chysler, Ford, Toyota, Honda, and Mercedes (probably more) all use
Chevron when testing their cars for the EPA/government--is it the Chevron
burns cleaner/better, is it that they all just wanted to use one standard,
is it an "arrangement" between Chevron and these companies? Just because I
wonder, though, does not mean we have to go impeaching anyone.
dapizza
It depends if it is low compression or high compression pistons. That is
why you need higher octane. Follow the manufacturer's advice. Stray away
from it and you may cause more harm than good.
"Manwe Sulimo" <manwe-...@attbi.com> wrote in message
news:LGlZ7.3006$Sf2.13978@rwcrnsc52...
Mischa Uppelschoten
http://www.caranddriver.com/xp/Caranddriver/features/2001/november/200111_fe
ature_gasoline.xml
I believe it boiled down to a performance degradation that's almost
comparable to the price difference. For example, a grade being 10% cheaper,
would also give you roughly 10% less horsepower. Now, this is for a good
few, but not all engines.
Mischa.
"N & A S" <a...@a.com> wrote in message news:3vRY7.8860$DY1.517742@rwcrnsc54...
Maddux
higher performance with higher grades of gas...
"Mischa Uppelschoten" <mup...@hotmail.nozpam.com> wrote in message
news:a1aloi$1cj$1...@nntp9.atl.mindspring.net...
M
a company says something is designed for a certain grade of fuel then one
should buy that fuel. What you risk is sustained pre-ignition (which you
may not be able to detect with your ears in a car like Lexus). The control
system may not be able to completely compensate with spark timing due to
combustion chamber geometry or deposits from normal use - causing a hot spot
and low octane fuel preignition. This can damage the engine. Read the
technical specs on the LS400 or LS430 V8 and you will see it's one of the
most mechanically precise engines ever made in a production environment.
It's more precise than a lot of race engines. That also means that you may
not hear ping in a tight fitting piston to cylinder design. Remember ping
is the "slap" of the piston skirt to the cylinder wall from the torque
generated from an off center ignition point. Extremely close tolerances may
not produce much of a slap.
Ever price what a rebuild costs on a Lexus? You will never save enough
money to pay for the risk by using a lower grade fuel.
Now lets talk about the original question of the Rx300. The engine is a
standard Toyota V6 3000 cc. The combustion geometry of this engine, I
believe, has been proven to be very compatible with 87 octane. Hence, the
control system adjusts to high octane fuel by advancing spark timing but the
engine and control system design basis is for regular. I don't see why a 3
liter Toyota V6 in a Lexus/Toyota shared platform would have any trouble
with regular or premium.
Stay away from alcohol blended fuel IMHO.
Regarding fuel with alcohol blend. You will get a little more octane but
you will dilute the energy per unit volume of fuel. Hence you will get less
distance per mile or more L/KM (for the metric world). The loss in economy
and performance is not offset by typical price differentials between the
fuels. Plus, alcohol over time, can attack certain metallic components and
seals in your fuel system.
Hope this helps or at least provides something to think about.
"Maddux" <do...@sendtothisaddress.com> wrote in message
news:UwE%7.11885$_p.53...@typhoon.tampabay.rr.com...
ladyh...@gmail.com
lexus requires high octane gas
like someone said , if you are going to put cheap octane gas in a Lexus, dont buy it...and this goes for BMW, Mercedes, Audi and any good car...
now...Mazda's 3 take whatever...!!!!! the cheapest u can find, bcs of the processing the skytech gives the gas....then again, the Mazda 3 is a very slow car with no kick or pick up....u can die driving a Mazda 3 if u have to accelerate to pass another car.....it just won't do it.
ladyh...@gmail.com
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> > Follow the manual. Most Lexus' (if not all) require high octane fuel.
> >