This may be a dome question for lots of you (sorry) , the only Dome question is the one you don't ask!!!!!!


Is there HP lost depending on octane fuel 87,89,92,93,94?
If there is any , any one knows how much?

I was told ones that if I use 87 I loose like 5 HP in my car compared with 89 octane.

 

Ralliarts are designed to run on 87 octane fuel. You won't see any improvement in HP no matter how high an octane fuel you run without modifications that would require a higher octane such as RRM's piggyback or forced induction. The reason for higher octane is to prevent detonation, it can't make more hp on it's own.

 

they dont even sell 87 octane here. 89 91 or 93 only. wierd...

 

I do notice better gas mileage when running premium though.

 

when i changed my spark plugs i noticed premature detonation when i run 87, and all i have is intake and exhaust. I think with the ralliart even though they say 87, i think it would be good to run 89 if you have a few basic mods but nothing higher then that.

 

I've been using 93 because I can tell a difference in how the car runs when I use 87. MPG being the main difference. I have also noticed with my injen cai and ****ty custom exhaust the engine is running lean. I've checked my spark plugs mutliple times and see white/yellowish residue on the tips so I feel safer running 93.

 

Lean as you are putting it is not a bad thing. Only a wideband will make you positive of what is actually happening.

 

same here , and my ra always feels alittle slugish when i use regular so i just mostly use a mid-grade

 

Interesting.... I may have to try midgrade. I've always gone with 87.

 

I used to think it was worth it to run mid grade as well but do the math. Mid grade is usually 10 cents a gallon more than regular 87 octane. I normally got an extra mile or 2 per gallon in efficiency max. It's close but it doesn't make economic sense unless your really NEED higher octane. As far as getting pre det on your spark plugs... I can't say how you're driving since I haven't seen you but... With an intake and exhaust you shouldn't see any at ALL! Your engine is equiped with knock sensors to prevent detonation from happening so unless you've done something you haven't listed you either get your gasoline at a Shell station or you have some serious problems. I say Shell because their gas leaves yellowish deposits on valves and plugs, try a tank of Amoco Silver to get rid of it.

 

Thank you all for the info

 

i prefer chevron with techron.