b1gredek

i specifically said the nonturbo so the compression should be just about the same as the supra, correct me if i am wrong....... i figure the supra is a sports car and it should be tuned to be faster than a gs,,,,, if anything both cars should require the same gas, if not the supra should require higher than the gs,,,,,

joshoowa

iTrader: (1)

i thought vvti controls something about the gas inlet and what not? it like regulates the gas so for instance regular fuel wont preignite? i could of sworn i read that somewhere.....

i always use premium but there are instances when i use regular, like once in a blue moon

middle grade gas (i believe 89 octane) is just a hoot, gas companies created that stuff just to get ppl to buy it... i have not seen any car that has said it requires middle grade gas..its a rip IMO

RRocket

Not true. Other factors including load and temperature certainly determine how much timing the engine pulls out. If it's warm out, an engine running 91 will pull timing out sooner than an engine with 94. Our GS is considered a high compression engine, so the higher the octane the better, to a certain point. 94 is readily available here, so that's what I run.

mr. aristo

thats what i use in my car

b1gredek

i have no problem with pumping premium,,,,,, i am just wondering if lexus is trying to pull something on us, just because its considered a lexus, we need to pump premium,,, but u can buy a toyota sports car, and pump regular,,,,,,,, doesnt make sense to me..... unless somebody knows the real facts on why we really need premium

LEXUS_KID

iTrader: (4)

Why wouldn't you burn the premiun gas how much is it out there buy you

imjohnphan

hahah i pump medium (89 octane) ... i hope nothing will happen to my car.

sockfocks

iTrader: (1)

ok...say your high mileage engine has carbon deposits in it and you put 87 octane in it since you bought it....you went and had a tune up and timing is set factory, then you start noticing a ping on hills and acceleration. Then you put the next higher octane gas which would be 88 or 89 octane. and that would eliminate the pre ignition that is occuring. This mostly applies to older vehicles which had carburetors or older fuel injected cars which burned fuel less efficiently and left carbon deposits inside the combustion chamber which can glow and can be a source of pre-ignition. http://www.howstuffworks.com/question90.htm

Roy860

Same here i put 89 in my car

gsean400

You should know that this thread is 10 years old. Also, your knock sensor is what allows you to run 89, it retards timing as said. If your knock sensor breaks and you have 89 in your tank, hopefully the little money you saved by using 89 over premium will buy you a new engine.

SC4Paulo

iTrader: (2)

my knock sensor and lack of 02 sensor for a while made my car run like doodoo, lack of 02 was probably what caused the KS to go out on me, after i replaced both my knock sensors and 02 sensor the car ran amazing. I always put premium in just because i truly do notice my car doesnt perform as well as it does on premium. I just bite my tongue and pay up. Gotta pay to play, and I enjoy the performance out of my vehicle. I have put too much time and money into getting the motor where it is at this point maintenance wise to not be able to enjoy it at its highest potential. 7.5-8 gallons was barely getting me 100-120 miles. im getting upwards of 160-180 now after i have replaced my 02 sensor, plus I chilled out on romping on it all the time, now, but i still do it quite often so im happy with my MPG now.

GabrielM

What year and model is your Lexus?

titangts

The reason it needs a min of 91 is because of math. Engineers do you not get bonuses from the gas companies to slap a label on the car that say " premium only ". They design an engine and based off ignition timing and compression ratio a determined octane rating is involved. I'm not an engineer, nor do I question them.

at the end of the day you get what you pay for. If you pay for cheap gas, do not be surprised if you end up with a "cheap" car,ie: mechanical issues down the road due to cheap gas.

My 99 GS300 has 240k miles and runs like new. I follow the maintenance schedule and use all fluid that were designed to function with the car.

Another Great example of questioning math is as follows:
My friend had a 03 CBR 600 F4i. Honda recommended 87 oct for that Sport bike. My friend just got the bike and filled up with 93. I said what the hell are you doing? He replied, " I only run premium ". I then told him how that's not is required of the bike. Long story short, his bike ran like total garbage for the following week. He called me that next weekend and said, " I'm never running premium in that bike again, it was horrible! " I later jokingly stated, " bro you're not an engineer that designs Honda sport bikes, do not question them".

lol