What Type Of Gas Should I Use?

[ilovefood]

Hey guys, I'm new to the club, just purchased a ES300 recently, and now I am thinking about what type of gas to use. Normally with my parents cars, which are bought from new, they use premium. But since my Lexus has already ran 101k miles, what type of gas should I fill it up with? Thanks.

[RX300ES300]

Regular is good enough, unless you have too much dough to burn.

[gbhrps]

Premium fuel was required for my wife's old 97 ES300, her present 04 ES330 and my Nissan 90 300ZX. But we have used regular unleaded fuel in these cars since the day we purchased them. There have been absolutely no mechanical or performance issues at all in over almost 400 000 km that these cars have travelled collectively.

However, neither my wife nor I drive these cars hard. Nor will we ever do so. Maybe both of us being newly under the heading of senior citizens is the reason. The cars' ECU's will automatically retune the engine parameters to prevent preignition with the regular unleaded fuel, if you are not constantly demanding top performance.

But, if you are the kind of driver to drive a car hard and are always on the gas asking the tranny to kick down .... do yourself a favour and spring for the extra cash to use premium. A burned and melted piston is a very expensive wake up call.

[ilovefood]

Regular is good enough, unless you have too much dough to burn.

I don't =[[

[ilovefood]

Premium fuel was required for my wife's old 97 ES300, her present 04 ES330 and my Nissan 90 300ZX. But we have used regular unleaded fuel in these cars since the day we purchased them. There have been absolutely no mechanical or performance issues at all in over almost 400 000 km that these cars have travelled collectively.

However, neither my wife nor I drive these cars hard. Nor will we ever do so. Maybe both of us being newly under the heading of senior citizens is the reason. The cars' ECU's will automatically retune the engine parameters to prevent preignition with the regular unleaded fuel, if you are not constantly demanding top performance.

But, if you are the kind of driver to drive a car hard and are always on the gas asking the tranny to kick down .... do yourself a favour and spring for the extra cash to use premium. A burned and melted piston is a very expensive wake up call.

I have a tendency sometimes to gas hard, and have the tranny kick down, so yeah I think I might stick to premium, unless I really turn super broke, Thank you very much for the advice. And no, I do not want a burned OR melted piston.

[gbhrps]

I should add that before fuel injection became the industry standard, it was very easy to hear preignition when under hard acceleration on just about any car that was running regular gasoline, and not the premium fuel that was required. Under hard acceleration you could hear the hammering from the engine that sounded like someone was under the hood with a wrench bashing at the engine block. It even continued when the ignition was turned off, as some engines continued to run on with shaking and stumbling until you suddenly popped the clutch to stall them out.

With fuel injection the computer reads all of the engine inputs and instantly adjusts all parameters to stop preignition with lower octane fuels, ...... up to a certain point. Continued hard, demanding driving, while using lower octane fuels, will eventually do major engine damage since the computer can only do so much.

[rlx101]

WTH gas has to do with miles? check your manual, if they say reg is fine - use reg. if they say use premium, dont use reg - use premium. CPU in my '02 ES300 can adjust from reg to premium fuel, with premium i may get better mpg's but not sure if its worth extra $$$.