Hi Guys,

saw a few gas station in Vegas offering 100 octane fuel all the time and was wondering if it is ok to put in 2-3 gallon of 100 octane with rest 91 octane mix to clean my gas tank and engine a bit?

i am driving a GS450h with almost 100k on the clock and thought maybe its not too bad to do it once to treat the old girl something nice or is it really bad for the car?

pretty sure our 3.5L engine weren't meant for that high compression but with that 93 mixture good?

tried to search the forum but didn't find any answer was wondering if any of you had done it, not looking for performance at all just curious

 

I wouldn't even bother. The GS450H engine is actually a de-tuned version of the GS350. Higher octane does not = better gas. If you want to treat her right replace the spark plugs!

 

won't do a thing other than cost you more. higher octane does not clean... it does not give performance, nor is it good or bad for an engine. The octane rating simply indicates at what compression the gasoline will ignite without a spark, causing knocking. As a matter of fact it is possible to have very bad gasoline with high octane rating... one such gem was leaded gasoline.

The engine is designed/tuned with a specific compression ratio and that dictates the recommended gas. using higher octane rating does absolutely nothing, using lower octane will cause knock which the ECU may or may not be able to compensate for by just wasting gas.

If you want to maintain your car (not a one time treat), do research on the available gas. All gas stations advertise all sorts of detergents and other cleaning agents... which in my opinion is marketing speak for "fillers". Also note that some gas, regardless of octane rating contains ethanol (Cuz mutant corn is so dam cheap in the USA and Monsanto has a good lobby) which is actually pretty crappy for any combustion engine. Some gas stations have the nerve to sell premium (91 octane) gas that still contains 10% ethanol (Petro Canada).... and they still charge as much as the one selling without (Shell or Costco)

 

All the gas stations in NYC have 10% Ethanol....If I can find a gas station without I would of gladly used it.

 

Like others said, there is no point.

 

thanks for the answer guys,

i will stick with regular 91, good thing for nevada is there isn't any gas station with 10% veggie oil yet, but pretty much anywhere in Cali has 10-15% of it, but that's interesting never heard the car will actually dump wasted gas if they are lower quality.

 

A lower octane fuel can cause pre-ignition if the engine compression is high enough, when the knock sensor goes off the ECU responds by retarding the ignition timing in order to minimize engine damage.

The effect of retarded timing is that you have less engine power and decreased fuel efficiency because:
- Some of the fuel ignited on the compression cycle, so there is not enough fuel for a full power stroke
- The remaining fuel is ignited on the down-stroke and not TDC when power delivery is less than optimal (piston already has downward momentum toward exaust and now the ECU wants to make sure whatever fuel was left is used up before it comes out the cat and exhaust)

So basically you burn gas to do nothing....maybe the word "dump" was not accurate, but the intent was to imply that gas gets used to do nothing.

 

Tried VP MS103 high octane fuel on my GS460, didn't do **** for me!