unleaded, and leaded???
 

i was wondering, i just noticed this one gas station in town here that sells racing gas at 110 octane, and i was wondering can you mix that with premium gas or regular gas???

I don't know if it'll do really bad things to your engine, but I seem to recall hearing that it will do really bad things to your catalytic converter. This means that if you're in an area with emissions tests, you'll fail them. Then you'll go get a new catalytic converter. Then, out lots o' $, you'll pass unless the leaded gas did bad things to your engine as well.

Oh, and I doubt that you could do things to our engines that would make them need 110 octane. Octane isn't a measure of power, it's a measure of how well the gas resists igniting too soon when injected into a hot cylinder. You could probably get hot enough to need that by running with no oil or coolant, but by the time you got there you'd have no need for more fuel.

Why the hell would you use 110 octane gas in a street engine? Just use diesel. It will get you just as far.

Please, everyone ignore the previous post... I'm not trying to be a dick here... but that's just plain fucking silly. Have you ever run your car at the track? Have you ever paid the $3.50+ per gallon for 110 octane gas? Has your car ever given you any type of pleasure other than beating other cars? Well.. if you put 110 octane in it... trust me.. if it could pleasure you.. it would. As for mixing 110 octane, with regular gas.. I don't see it being a problem (please correct me on that if you know otherwise) but putting diesel in your car, will not get you anywhere but in need of a new car probably.

You are going to put 110 octane gas in an engine meant for the street? Thats for highly modified engines. Not daily drivers. May not hurt anything but not much of a point to it either.

Note: And he's driving a P5 so more likely than not most of it is stock. Stock compression, timing, etc. In the past when I have worked with people running dragsters they move to racing fuel when they increase the compression to abnormal limits to fight preignition.

Not trying to be a dick here or anything.

Just so we can revisit this issue again I was looking and there are several good primers on the web about when to use higher octane fuels. Try doing a search on Google for the terms "Racing High Octane Fuel" or something similar and just read a few links.

So, basically if you read those its not an issue. Unless you just plopped down 1500 or however much Mazdaspeed wants for their high compression engine upgrades. Which for a four-cylinder it usually pays off better to go forced induction instead of naturally aspirated. A V6 or a V8 will get good gains from regular tuning, as the F150 will attest (and it has beaten quite a few cars in its time, could it be the 5.8L of fire breathing power?).

And the diesel thing was a joke. Duh.

holy shikes! you can get racing gas in your town?!?! lucky. i dunno if it hurts your engine but i sincerelly doubt it. it simply avoids detonation and has more explosive force when it burns. you should try mixing it with premium gas in different amounts and see what happens. no point in running it on the street though, go to the track!