Hey guys,

(noobie question - sorry; searched but only found race track fuel related)

I think over the week I've noticed the power in the car to not be as responsive as it usually is.

The tank is near empty, but I was just wondering, if there is less fuel in the car, hence, less fuel to burn, does this affect the output of power the car is to produce?

Anything else I should look out for?

Note:
Serviced at 1500km, now 3790
No Mods

Thanks for your help fellas (,")

 

no, but temperature has a great deal to do with it. Has it been warmer this week? Fuel also has less energy per gallon when it is warm, since it expands when heated. So your injectors may be flowing at the same rate but you are actually getting less energy out of your gasoline.

 

Hey Dan, it's actually been both warm and cold. Not hot, just warm, like a nice warm.

Weather Cold = Less Power
Weather Hot = Less Power

I'll tell you what it like.

It feels like when I step down on the accelerator, the power is being given to the engine, but the engine isn't pulling out of the power band... or something.....

Hope that makes sense...gawd...anything else?

 

maybe need to calibrate the butt dyno?? My car seems that way sometimes too, and other times it seems super fast. I think it's a perception thing more than anything else. Don't know though.

 

I get the same feeling u do. Some days it feels sluggish as hell an some days i just leave dan in the dust. I dont get it either

 

I dont' know about this car but I have had cars that actually felt a little bit more powerful on a full tank.... Now I didn't get any dyno readings between a low and full tank but it sure seemed like it. It could just be my imagineation that the tires chirped quite a bit more; however, it could have been the result of extra weight.

 

are there any other "symptoms" you could tell us? does everything else (braking, handling, idle, etc.) feel normal? what octane and brand of gas are you using?

anyway, i have the same type of thing happen to me in the evo (in regards to ambient temperature and humidity). lately the car feels slow as hell (relatively speaking of course) because its been so warm and muggy out. i can't wait until that first crisp day of autumn where the engine feels brand new and pulls like a fighter jet.

 

What fuel do you use? I just run on premium and really notice if someone else fills it with regular its like "What the...?"
Other than that if you have any more weight in the car than usual that can really make a difference.

 

Well using premium fuel in our cars is not going to make any diff, except in your pocket. My car also do that from tome to time, i believe it could be the ECU switching maps depending on your driving. Our computers, as well as the computers on most modern cars are constantly making changes in the car (i.e. fuel map, timing) depending on your driving and other variables. Sometimes the ECU will get stuck in a crappy map and will feel the way you r describing.

 

I'm thinkin less fuel = more power

The more fuel in your tank, the heavier the car, hence slightly less power

 

I thought something like that was happening, would explain why it would be a bit sleepy when pottering around, but staying 3vil when tearing around. Nifty

 

first of all if you're driving a ralliart you should NOT be using premium fuel (unless you've had a reflash or turbo). the 2.4 mivec was designed to run on regular fuel and you will get WORSE performance and WORSE gas mileage if you use premium. a common misconception is that higher grade gasoline is "cleaner" or "more powerful" which simply isn't true. higher octane burns slower so that cars can run at high temperature and compression without the gas have uncontrolled ignition (aka detonation).

so, first things first, switch to regular. i'd use either shell or chevron gas (if you have it over there) as they have the highest quality of fuel additives. see www.toptiergas.com for more info.

 

I've felt like my car runs better on a new, full tank of gas - I attribute this mostly to having a fresh tank of cooler gasoline in the car when i drive out of chevron. The less gas you have in there, I suppose in theory the more easily it could be heated leaving you with less power. The engine itself will make no distinction between having more or less gas. Just gas, or no gas.

 

I've noticed that when my gas gets low (1/4 i guess) it seems a little unresponsive until i fill up. and somedays it isnt all there. i think that has to do with weather and how i drove it a day or 2 before since the fuel curves and everything continuously shift according to driving style.

 

So why is it I can really notice less performance when its got a tank of regular?