GSman

iTrader: (2)

Hi,

The owners manual recommends the use of gasoline over 91 octane. Wanted to know how strictly you need to conform to this requirement. Has anyone tried 89 or 87 and if so, any complications or noticeable performance degradation?

Thanks,

GS4Will

though premium gas is too much $$$ now, i would not even think about taking chances on a $40-50k car, not worth it.

i did, however, tried the 87/89 deal on my buds leased 00 Q45-perfromace lag BIG time.

GlobeCLK

iTrader: (5)

My area (most of SoCal) has 92 Octane as the best gas. Some places sell 93, does it mean if i use 93 octane my car will actually be alittle faster?

What's the highest octane a GS should use? Is it suppose to be like 10x the compression ratio? (9.8:1 car, use 98 octane the most) something like that?

UK_GS300

In the UK and most of Europe the minimum is 95RON and the Super Unleaded is either 97 or 98 RON.

I don't understand why Lexus detuned the engines over here since we have better gas. The UK Supra TT put out 6bhp more than the US model because of it.

GlobeCLK

iTrader: (5)

Only US gets low octane gas.
Taiwan has 92 as low, 95 as regular and 98 as premium. (I think, the last time I checked)

RealMarty

You can use lower octane gas. The engine mgt system will set back the timing to eliminate knock and engine damage - but you'll also lose significant power. Won't feel like the same engine.

OK in an emergency if 91+ is not available otherwise not worth the few pennies saved.

BBD

guys am so broke that I cant drive my car anywhere ,,, but hence I would never ever put in my car lower than a 92 octane I usualy put 93, in Kentucky,, The higher the Octane the better combustion you will get, however if you go too high Octane like 100+ u will get missfire in the combustion chamber, the higher the compression ratio in your engine the higher teh octane you can go,,, and do not forget that Spark plugs do a big job as well, the higher you go you should go with Colder spark plugs and visa versa.

gs400tx

The octane ratings are a measure against detonation. They are truly dependant on engine, loads and environmental conditions.

If you exceed the octane needed, you will loose gas mileage. The lower the octane the slower the fuel burns and you are more likely to burn all available hydrocarbons before they go out the tail pipe.

bitkahuna

iTrader: (20)

We get this idiotic question about once a quarter. It doesn't say use 91 for grins or to make your wallet suffer. It says it for a reason.

If you want to save about $100 a YEAR on gas so you can have less power and possibly spend thousands on your ruined engine later, go ahead.

MikeGS4PE

I totally agree with bit...

Changing your driving methods might be a better savings... go easy on the throttle...

biggie27

I have used diffrent types of octane on my GS400 before and I also recomend using the 92octane too Ive tried using 89 before and not only did it loose preformance it also burnt gas just as fast if not faster

Ive also tried 120 oct. racing fuel ( I DO NOT RECOMEND THIS FOR DAILY DRIVING ) I have to admit the car was super fast I did feel a big diffrence there

GlobeCLK

iTrader: (5)

Anyone knows where to get GAS HIGHER THAN 92 OCTANE here in So. Cal? Preferably LA County or Orange County. I would really like to try that.

gs4power

You will not feel any difference with a higher octane gas. Only if you could make the engine to have a higher compression ratio (very difficult to do). Higher compresion ratio + better detonation resistance (+92 octane) = more power!!

LexRX

bitkahuna is right, just go with the recommended octane for your GS - the annual cost of gas for regular vs. premium gas isn't significant enough to matter, especially when you are talking about your engine.

BBD

Shell Stations, BP, and Exon all have 93 Octane for their premium, however it depends from one state to the other.