gophins349

i did my math by me going 200 miles on the tank of gas divided by the 10.5 gals i put in

i guess i will clean my maf and iat sensors and fill up on 87 and see what happens with it.

AGreen

I'm going to attempt to prove that 93 octane should not be used in cars that don't require it... just follow my logic.

High compression/turbocharged cars need 93. If they don't, they get a case of the knocks. They need a fuel that does not ignite without spark. 93 is less... volatile (for this discussion's sake). This means it requires more energy to combust. Higher compression engines put waaaay more energy into the atomized fuel in the form of heat. That's Boyle's law (IIRC). As pressure increases, temperature increases and vice versa. So if you use regular 87 octane in a boosted or high compression engine, the added energy will cause the mixture to ignite before it's supposed to and knock. Now, throw in a batch of the less volatile 93, and it ignites right on cue.

On the flip side, if you use 93 in a car that's meant to run on 87, while you may not notice any difference in performance, or your uber-sensitive butt dyno may tell you that you have 7 more horsepower, it's actually doing more harm. Since it's not going to completely burn, you'll use more fuel. You'll also be depositing crap all over your valves because it's not burning all the way. The O2 sensor won't like you any more, and your car will begin to hate you all over. And, yes, your power will go down because it's not as clean and efficiently-burning as your old 87 octane was.

That's pretty much the extreme of the spectrum there, but it's the truth. While most people won't experience gummy valves and poor performance, it will affect it towards the negative.

If I were you, I'd fix that AEM. Get a silicone coupler and reattach it where it was chopped. Yeah, your mpg will suffer from getting hot air in, but not that drastically. You're probably just using more skinny pedal to get the same performance from a cold air. 20-25 in town's not too good for a tiburon. 25-28's more like it. Just do like the other guys suggested and make sure all your maintenance is up to date. Plugs, wires, physically clean the throttle body and MAF sensor. And do get your fuel injection system serviced professionally. Find one that uses either a MOC or BG system. What they do is disable your fuel pump and bypass the lines such that the engine runs off nothing but a pressurized cleaner. I worked at many garages, and these things actually work. Correct tire pressure, good shocks, and good suspension components will also change your mileage. Even down to the type of transmission lubricant you use. Go with a high quality synthetic like amsoil or royal purple.

gophins349

can i use electrical clearner on my MAF and IAT sensors?

Ericy321

Use Mass Air Flow sensor cleaner only on the MAF. And Electrical is good for IAT.

DTN

um... wouldn't hot air INCREASE MPG? As the temperature increases, the engine adds less fuel per spray. If you're driving 35MPH (2000RPM) in 32 degree weather, the car adds more fuel to account for more air in the same space. If you're doing the same speed in warm weather, the car adds less fuel. I was under the impression that cold air = better performance and worse fuel economy, and the only modification that worked for better fuel economy and better performance at the same time was ECU mods and weight reduction.

Jason

<div class='quotetop'>QUOTE (Ericy321 @ Dec 20 2007, 07:16 PM) <{POST_SNAPBACK}></div><div class='quotemain'>Use Mass Air Flow sensor cleaner only on the MAF. And Electrical is good for IAT.</div>


I used electrical cleaner on both the maf and the iat. Is it bad to use it on the maf? Â

Too late now tho...

Ericy321

Im not sure really. I always use MAF cleaner only just because its made for that. The MAF element is very fragile and I dont exactly know the chemical makeup of electronic cleaner.