[aerostudent]

if you have done any reading you can understand the purpose of increasing octane. first lets look at what happens if you use to low of an octane in a high compression setup, you get deto, aka knock. the fuel and air are combusting too soon. how to fix that? we increase the octane. by increasing the octane we can increase the compression. why do race cars use 110? it is because of high compression, if they used 87 their blocks would explode.

 

[Egz]

D'uh, because it was designed for that.

Racers that use 110 have a reason too, they aren't running a stock engine, and in race environments, the harsher conditions can lend for a higher chance of engine knock. Detonation is a bad thing...

 

[Andy Smith]

Me and Toyota must be stupid.

You said it

 

[YellowSteel]

This discussion is worthless, the educated people know why higher octane gas can actually damage an engine which it's not intended for, and the other folks swear you can buy a bottle of octane boost and the car is suddenly just faster...

Do some research, find out how and WHY fuel combusts, and why it detonates early if it's too low of an octane. Then come back and provide reasoning which states a bigger bang with the piston at a higher position than was intended is actually a good thing. Not as bad as detonation maybe, but not good at all.

 

[blueovalbaboon]

think about it, high octane avoids deto. that means it's LESS likely to explode. which means it's HARDER to burn. REally not a difficult concept here.

 

[askjeffro]

Ah! Must resist learning something.. ahh no.. can not accept reality...

 

[Andy Smith]

Ah! Must resist learning something.. ahh no.. can not accept reality...

LOL

 

[Matt_Liq_Grey]

I have 10,000 miles on a PZEV ZX5 with problems that I don't quite understand.

Issues:
1. I like the power at 4500rpm and above but the transition from weak econo-box below 4500 to the wanna-be monster above 4500 is horrible. It's like fuel completely stops going to the engine for a half a second and then the thing leaps forward like hell. Makes judginf what the car is going to due a little difficult. Is there a way to smoth it out? Are they all like this? Is there a way to keep it in the "wanna-be monster mode"?

2. From the first day I had the vehicle, it bucks and stutters at a cruising RPM. Goes like this: If I am accelerating or decelerating it's smooth. If I am just cruising at a maintained speed these subtle bucks and flutters start happening. I took it to the Ford dealer (long story there) and they came up with nothing. They replaced the ECU to make me feel better and it made the problem just a little worse. Has anyone else experienced this? It makes me hate an otherwise great car.

If anyone else had the issue and got it fixed, please let me know what you did and how you talked the dealer into realizing your car actually had a problem. Thanks!

I did notice this problem with mine , but not as bad as your having, it was around 2000-2500 range if i was cruising with my foot on the pedal not moving the car would surge a tiny little bit i'd get a little agravated, then give it more gas and it would jump up and go...But what i did notice when i added the intake, it went away and that it would speed up quicker and there were no more surges. But my problem does not seem to be as bad as yours . I guess you could give the intake a chance, seeing that the dealer ship can't really help you, plus its a great upgrade, believe me you will love the power increas too...hope that helps

 

[tarball]

Hello,

I have also been part of a discussion on this matter over at focusfanatics (http://www.focusfanatics.com/forum/showthread.php?s=&threadid=10564) and would love to know if there is a solve to this.

Funny thing is, my car is less than a month off the lot and I've begun to encounter this VERY PROBLEM after an ECU update from the dealer. The engine light came on and the code was for "calibration" and the tech updated me to the latest software.

Since then, the car does the stutter thing you are describing and feels more sluggish. Let put it this way:

1st 2 weeks having the PZEV home: Kick Ass!!!
Since going to the dealer and getting the ECU update: Suck Ass!?!?

Car purchased: 03/16/2004
Dealer ECU update: 04/02/2004

Help?!?!?

Jeff

 

[sct]

I'd bet on either too much timing or too much EGR flow. The EGR things is easy to test. Pull and plug the EGR controller (can) vacuum line.

 

[Andy Smith]

Yeah that stutter happend on a lot of older focus' too. I've felt very minor stutters in mine...but i dont care

It's not that bad.

 

[fsfocus]

I have absolutely no bucking or stuttering at any time, I have a 03 Duratec with 900 miles.

 

[SoCalFocus]

I have 10,000 miles on a PZEV ZX5 with problems that I don't quite understand.

Issues:
1. I like the power at 4500rpm and above but the transition from weak econo-box below 4500 to the wanna-be monster above 4500 is horrible. It's like fuel completely stops going to the engine for a half a second and then the thing leaps forward like hell. Makes judginf what the car is going to due a little difficult. Is there a way to smoth it out? Are they all like this? Is there a way to keep it in the "wanna-be monster mode"?

2. From the first day I had the vehicle, it bucks and stutters at a cruising RPM. Goes like this: If I am accelerating or decelerating it's smooth. If I am just cruising at a maintained speed these subtle bucks and flutters start happening. I took it to the Ford dealer (long story there) and they came up with nothing. They replaced the ECU to make me feel better and it made the problem just a little worse. Has anyone else experienced this? It makes me hate an otherwise great car.

If anyone else had the issue and got it fixed, please let me know what you did and how you talked the dealer into realizing your car actually had a problem. Thanks!

This is exactly what I've been experiencing!! The first week it was great. But it's been 2 months and I can't stand the sputtering and flutters. I've actually named my car Stuttering John because of it. The half second hesitation before it takes off again is maddening. Mine does the exact same thing your does. I'm going to bring it up to my service manager when i go in for my first oil change. Has anyone else had this problem yet?
BTW mine is a manual with under 3K miles on it and i run 87 octane.

 

[jamhole538]

i just got my tsb/ecu flash and my car runs soooooooooo much better...no start up problems or bucking....guess my tech knew what he was doing or maybe you'll got lemons....you know it is a FORD...i love um but look at the history of the cars malfunctioning...keep taking it in and if they cant fix the same problem in 3 trys...BAM YOU GET A NEW CAR..well if you live in CA since we got a LEMON LAW

 

[firstonraceday]

After I installed my fs cai the bucking almost went away its so vague i cant tell when im crusing in 4th at 2000 rpms anymore so i think the air filter does not help in the stock version at all.

 

[texasgold]

A person comes in here to ask a car question and the thread get hijacked with people arguing about .50 cents a gallon on gas and octane. Welcome to 2023. I wonder how we got here

 

[hEaT]

A person comes in here to ask a car question and the thread get hijacked with people arguing about .50 cents a gallon on gas and octane. Welcome to 2023. I wonder how we got here

The last post in this thread is from 2004...