why are cars so picky about gas?

[themadness]

i have been gone for a little over a week and just drove my car this morning. of course its hesitating and stumbling with a 1/4 of a tank so i will be running a seafoam treatment today or tomorrow. then i began wondering why are cars so picky about gas? barring the fact that mine has been sitting up, every batch of gas yields different performance results regardless of the octane levels. even from the same store. i know the engine is never the same at any given moment but it seems like a routine of the same quality of gas would get similar behaviors in a car. or is it just me?

[3X00-Modified]

the quality of gas is never he same, thats the issue... and gas is the life of an engine if its crap it will run like crap.

[berettaboi]

try a few stations, see which one you car runs best on, then call someone and tell them about the water leaking into their inground tanks...

really, you shouldnt be noticing such a difference (when visiting reliable brands and newer stations)... depending on if you are going to different stations that mix more ethanol than others, or like i mentioned before, might have some water issues...

you may need a tune up including a fresh fuel filter.

[themadness]

i always use the same place except when out of town. even the higher octane stuff doesnt do much as far as performance. there is a station in town that sells "100%" but i havent tried it yet.

it has been sitting for about nine days which is probably the biggest problem. i did an idle relearn and that seemed to fix it. its a little sluggish to turn over still though(probably not related)

how long does it take for water to start forming in a tank?

[3X00-Modified]

even the higher octane stuff doesnt do much as far as performance.

I'm not going to beat this dead horse again...

there is a station in town that sells "100%" but i havent tried it yet.

it has been sitting for about nine days which is probably the biggest problem. i did an idle relearn and that seemed to fix it. its a little sluggish to turn over still though(probably not related)

how long does it take for water to start forming in a tank?

I only have access to 10% ethanol everywhere I go and I never have issues... Also my car sat for a month at least and it started up fine. I think you need to find a new gas station. But as far as 10% ethanol absorbing water here is some info from classic car owners issues with E10 due to fuel tanks that are vented to atmosphere and NOT sealed like a newer system is. You may just have a open hose to atmosphere causing your tank to absorb water much faster than a normal setup.

What happens to your car and it’s performance when water causes fuel phase separation?

Reduced fuel longevity: A gasoline/ethanol blend absorbs water until it triggers phase separation. The blend has a 90-day product life in a closed tank, but lasts just 30 to 45 days in a vented tank often found in classic cars. With 10 percent ethanol blends, owners are supposed to replace the fuel in vented tanks about once a month by driving or draining, taking into consideration the humidity in the atmosphere and temperatures.

Lower fuel octane: The ethanol in a gasoline blend provides some of the octane rating. When phase separation occurs, the octane rating of the remaining fuel can drop by as much as three points.

Poor engine performance: The fuel pump could easily pick up a slug of the water/ethanol slurry at the bottom of the tank, interrupting the flow of gas to the engine. This will cause the engine to miss, run rough and possibly stall altogether.

Corrosion and rust: Water in the bottom of the fuel tank and inside the fuel lines will cause corrosion and rust, and the solvent properties of the ethanol will loosen that up, along with bits of sediment and deposits. The resulting debris floating in the fuel could clog fuel filters, fuel lines and carburetor float valves.

[Slinky]

What octane do you guys run?
will higher octane such as 89 vs 87 hurt or help?

[3X00-Modified]

[scd88ga]

^^ LMAO, I hear ya!!! The fact that people STILL don't realize what the purpose of different octanes are for still makes me laugh! Like when the Honda fanboys get together and the guy with the 1.5 says he gave his baby a shot of the "GOOD STUFF" at the pump today... Ughhh drrrr......... Come on people, this is a Beretta forum, don't sink to the "HONDUH" level, damn....


READ THIS DAMMIT!

Mythbusting Octane, The Truth About Gasoline

What Does That Number on the Pump Really Mean?

In the automotive world, there are many common myths, which are repeated so many times that, after a while, they eventually transform themselves into ‘facts.’ Unsurprisingly, many of these ‘facts’ have to do with gasoline, whether they be regarding fuel mileage, power possibilities or some other arcane aspect of the internal combustion engine. Gasoline can be a confusing topic, and it is easy to make assumptions about it that may seem logical, but which on closer examination, turn out not to be true. A perfect example of this practice can be seen with octane ratings.

What are octane ratings? Simply put, when you pull into the gas station and are presented with the array of different fuel grades that you can pump into your car, the numbers written above each button or nozzle indicate that particular grade’s octane rating. Typically, the range will run from 87 octane on up to 93 octane.

In the world of automobiles, it is tempting to associate higher numbers with higher quality. After all, more horsepower and more miles per gallon are a better thing, which feeds into our perception that more impressive octane ratings also equal higher performance. Gasoline companies understand this mentality and do nothing to dissuade drivers from it, labeling 87 octane gas ‘Regular,’ and 91 or 93 octane ‘Super’ in an attempt to reinforce this way of thinking. After all, since ‘Super’ is priced higher than ‘Regular,’ it’s in their best interest to convince as many people as they can that paying a bit extra means getting better quality gas.

Unfortunately, this is where the myth of what gasoline’s octane rating really means creeps into the picture. Time and again, people will be told that high octane fuel burns cleaner or more completely, and that it will give them extra power and better fuel mileage than Regular octane gasoline because it contains more ‘energy.’ These blanket statements are simply not true. In fact, the octane rating for gasoline has nothing to do with the amount of power locked inside of it – it actually relates to just how much a fuel can be compressed before igniting. The higher the number, the less likely it is to ignite under pressure.

Why would anyone want to produce a fuel that was actually harder to ignite once inside an engine? To understand the role that octane ratings and ignition pressures play in a motor, it helps to be familiar with the term ‘knock.’ Essentially, when gasoline is sprayed into a cylinder by a fuel injector and mixed with oxygen, engine designers expect it to remain there in vapor form until it is time for the sparkplug to light it up, causing the explosion that drives the piston down to generate horsepower. The timing of this explosion is critical, as gasoline that ignites too early causes ‘knock,’ which reduces engine output and efficiency and which, in worst-case scenarios, can actually physically damage an engine.

In most engines, knock is rarely an issue because the compression ratio – that is, the pressure that the air/fuel mixture is put under in the cylinder – is low enough that Regular gasoline’s octane rating is sufficient. There is absolutely no benefit to running Premium fuel in a standard motor, since it will never be able to take advantage of that gasoline’s higher knock resistance. However, more aggressive engine management schemes, especially those found in turbocharged or supercharged vehicles, can turn up the compression to a high level, requiring much higher octane gasoline to avoid knock.

How can you know whether your car actually requires Super gasoline or whether it can get by on Regular? Almost every vehicle will list the octane rating necessary to run it safely inside the owner’s manual. Some luxury or sportscars might even place a small reminder on the gas gauge itself stating ‘Premium Unleaded fuel only’ to make sure you don’t forget.

To wrap things up: no, you won’t see a power or fuel efficiency increase by running high octane fuel in an engine that has been tuned and designed for Regular gas, nor will doing so perform any extra ‘cleaning’ inside the motor. On the flip side, running low octane fuel in an engine built for Premium can increase the risk of engine damage and will certainly impact that unit’s overall performance. The next time someone tries to pass these myths off on you, you can try explaining to them how octane ratings really work – or you can just smile and nod, pay for your gas and move on.

GOT IT?!

[Slinky]

XD i did not expect anyone to repost that stuff, i just posted it because Jon said about beating a dead horse hhaha

[#1 stunna]

... But what if i get 93 octane and put some nos super octane booster in with it ? Bet that would make some "real power" LOL @

[3X00-Modified]

It's amazing how a word can be marketed to confuse and take advantage of so many people... "PREMIUM must mean it will run better".... Just like the new coined phrase of Artisan... I have trouble believing bagels from a coffee shop giant Dunkin Donuts is Artisan in any way...