What does GM do differently for the overseas H3's since some places in Europe only have like 100 octane.

 

I didn't think you'd get that much better from 93 octane - I just ate my words! Good job. Let us know the MPG after you use more gas.

 

I think in Europe the octane rating is a different formula...As 100 there is like 92 here.

 

We have 100 octane as well, but you have to sign a waiver when you buy it saying that you are putting it into a jug to take to your home-hangered airplane. It also contains twice as much lead as automotive gas once contained in this country, but that is for what is considered low lead gas.

 

The only reason you would get better fuel economy by using a higher octane fuel is if the lower octane is not burning properly and is causing preignition and knock. This would result in a loss of power from the fuel that is being consumed, and a loss of power from the engine trying to fight itself to run, not to mention the damage that will eventually result to the engine.

Now that I think about it, I have heard my engine ping a couple of times when I start off. Maybe I should try a higher octane too.

 

I've created a monster(s)

 

Keep in mind, the higher the octane, the slower the burn. For pre-ignition conditions, there could be valid reasons for utilizing higher octane gasoline. Example, towing heavy loads. Another example would be areas where fuel quality is questionable. I run into this issue in the back country where fuel has sat for an extended period of time. Obviously, this is not a good thing any way you look at it. I try to compensate for the degradation of the fuel by utilizing higher octane- although, it is rather doubtful that it is helpful.

Our H3's are tuned for 87 octane fuel. Routine use of anything higher is a waste of money. In theory, due to the slower burn, creation of deposits would accelerated. The engine in the H3 does sense knock, and change the timing to compensate.

87 octane is going to provide you the most power and and provide the cleanest (and most complete) burn.

 

I'm experiencing Deja Vu[sm=smiley29.gif]

 

OK OK You guys have convinved me That's why I joined this forum. I knew I would learn the best from the best. Even though I notice a power increase, which is becoming more noticable the more I drive it (I have 18k miles on it so I can tell from driving it every day) I'll switch back. I'm not willing to take the chance that in the long term I'll ruin my cylinders. I'll just make sure no matter what road trips I take I always stay consistant. I do think about how long that higher octane has been sitting in those tanks considering gas prices.

My conclusion for this little experiment:

Better gas mileage: eh, maybe 1 mpg more, but probably not since I haven't had the AC on, so Not Really

More Power: Yes, noticable, but dramatic, no. Worth the long term damage to your engine? no, not for the little bit you gain.

Using a Magnet: Made me loose mileage. How? I have no idea because in theory, it should not effect it either way, but I'll tell you, it made it worse, definitely.

Extra intake holes in the top of the air box cover: No difference at all (except the extra hot air getting sucked into the engine making my mileage go down the crapper. Good thing I could seal it back off)

Am I a sucker? Well........

[IMG]local://upfiles/863/8D3AAB7AA35443EF8E2F62503B678FB6.jpg[/IMG]

 

Thank you for that self photo....[sm=badbadbad.gif]