View Poll Results: What Octane do you put in your '98 - '05 GS4?
86 or below (available in Ohio, Michigan, Indiana, West Virginia, Kentucky, etc.)
0
0%
87
6
4.41%
89
8
5.88%
91 (does 91 exist? I'm not 100% certain.....)
45
33.09%
93
71
52.21%
94 (Sunoco)
3
2.21%
95 or above
3
2.21%
Voters: 136. You may not vote on this poll
What Octane do you use for your 1998 - 2005 GS400?
04-28-06, 11:19 PM
#32
Driver
Join Date: Jun 2003
Location: International
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I voted 91, but that's because I use 92 and it wasn't listed.
Octane requirement for the engine (not what the driver "thinks" is best for whatever reason) is dictated by throttle opening. If you don't use full throttle, and just drive gently all the time, the engine will be perfectly happy on 86, and not knock or retard timing at all. If you use full throttle, then the octane requirement goes up and 91 would be needed to maintain ignition timing.
All octanes are equally well refined and blended, there is no difference in quality other than the anti-knock value.
Hasn't this topic been beat to a pulp before?
Octane requirement for the engine (not what the driver "thinks" is best for whatever reason) is dictated by throttle opening. If you don't use full throttle, and just drive gently all the time, the engine will be perfectly happy on 86, and not knock or retard timing at all. If you use full throttle, then the octane requirement goes up and 91 would be needed to maintain ignition timing.
All octanes are equally well refined and blended, there is no difference in quality other than the anti-knock value.
Hasn't this topic been beat to a pulp before?
04-29-06, 05:16 AM
#35
Racer
The desire for higher octane fuels is nothing more than successful, misleading advertising by producers.
Higher octane than the car is tuned for won't make your car do anything better and is thus wasted money; lower causes the car to retard performance.
If the car wants 91, that's what you should give it.
Higher octane than the car is tuned for won't make your car do anything better and is thus wasted money; lower causes the car to retard performance.
If the car wants 91, that's what you should give it.
Last edited by jonathancl; 04-29-06 at 10:05 AM.
Slow or Fast Burning?
04-29-06, 08:57 PM
#37
Lexus Champion
Down here in Alabama we only have 87 89 and 93 so I use 93 for my baby. I dont know about burning slower but I think the higher the octane the harder it is to detonate.
04-30-06, 06:04 AM
#39
Lexus Test Driver
Higher Octane means a higher burn temperature..
Originally Posted by TAMR_GUS98
O.K. Let me ask you guys this. Is higher octane fuels slower or faster burning?
Rock
04-30-06, 10:26 PM
#41
Lexus Champion
Slow Burning.
Originally Posted by Rockville
so that is slower. Preignition is when the compression and friction prematurely light the lower octane fuel and on some engines can do damage. The fuel efficiency will be worse on an engine designed for Premium octane if you use Regular so the savings may be illusory. If you have greater than 10:1 compression the fuel choice should be 91 or higher Octane. This is explained on the last page of the owner's manual. If you are running out of gas and Premium is unavailable put the lower octane in enough to get to a source of Premium. Do not floor it as that will cause predetonation. Conversely, if you own a car that is designed for regular unleaded then putting high octane fuel in it would be a mistake also.
Rock
Rock
05-02-06, 04:44 PM
#45
Pole Position
regular unleaded is 95 here in the UK. they recently brought out 99 octane super unleaded, which is supposed to benefit turbo engines. and also we have 102 octane that just got released. I typically fill up my GS with 99..