TLEX

I was wondering which octane you guys use because around here I can't seem to find anywhere that has 92 octane anymore. Every gas station I go to seems to only have 91.
There shouldn't be that much difference in performance I would suspect right??

BadBtsz4u

I use 93 occasionally 94

-Lexus-GS400-

Just buy octane booster...

bitkahuna

iTrader: (20)

I think it was Car & Driver that had an article about why California now doesn't have 92 anymore. I think it was to do with some regulations put in place (on the additives).

I think the GS needs 91 or above, so 92 or more isn't going to make any appreciable difference.

GlobeCLK

iTrader: (5)

does octane boosters even work for a GS? I've heard that the computer will know if you get some sort of sudden boost in octane and will not run the car like it's got some extra boost.

MGS4

The manual says 91 or higher. So I think you're ok. I usually run 94 octane Chevron gas. If money is tight, I run 92.

1niceride

Bit is correct . I read it in the USA TODAY that CA was not getting 93 octane anymore . Just 91 , something to do with regulations. Like everyone has mentioned , you won't feel the difference between 91 and 93 octane.

GS430 GUY

From what I read, I think it was in one of the magazines mentioned, the reason for 91 octane was a two-sided issue. Gas prices had risen sharply (we all remember that) and MTBE (an additive) was being phased out. This made it harder to make 92 octane since it takes longer without MTBE being added. So Cali decided to make 91 the highest octane with 92 expected to return in 2002. This put more product on the market and helped to keep prices from sky-rocketing even more (so they say). I am sure Mean Gene can give more detail if needed since he is a petroleum guy. Bottom line was 91 was fine to put into your car if it requires premium. So don't fret looking for higher than 91. Hope this helps.

GS4IV

I had some correspondence with Lexus on the subject and could not get a definite answer.
Being an advanced engine management system I thought that the higher the octane the better the performance. A lot of european makes state this in specs. The computer monitors for engine knock etc. and adjusts the timing to derive the best performance without knocking.
If the Lexus works the same way we could use any octane grade without problems (other then loss or gain of performance).
When I asked about octane requirements I was quoted the figure in the manual, when pointing out the above I was told that that is how the engine management works.
In Toronto we can get Sunoco Gold (93 or 95 octane - not sure) - I tried all grades from 89 up but really can not tell for sure what is happening.

bitkahuna

iTrader: (20)

Much better than high octane gas is cold air/weather! I've noticed that since temperatures in Atlanta have dropped in the past few weeks my car is NOTICEABLY quicker.

Johnny Mo

In a recent issue of Car and Driver they do a comparison test on cars and the gas used, based on the manuf. recommended octane type. In cars rated by the manuf. for 87 pump octane, using premium 93 octane made no significant improvement. In high perf cars, like an M3 premium was recommended, and when 87 was used the knock sensors and engine management computers took over and retarded timing to adjust for the lesser quality fuel causing some (worse) but also not significant difference in performance.