Premium ??

[GTZeeya44]

just got an 2k gtz and after the dealership gas runs out should I put in some premium ?

[Titanium2K2]

yeah, the v6's requires premium fuel. The I4's doesn't but I still put in premium https://www.thegalantcenter.org/style_emoticons/default/biggrin.gif

[GTZeeya44]

thanks i thought it would need it

[pinoyesv6]

its highly recomended that you put premium in your car. the car will still run if you use regular unleaded.

the other day i put regular grade gas in my v6. i did notice a difference between premium and regular. nothing major in my case, kinda like a slight loss in peformance. haven't experienced any long term effects of using reuglar but yea,i always put premium. but in this case, it was either put premium and run out of gas half way home or put regular and make it home.

[manybrews]

if, and ONLY if your car has a stick saying "premium recommended" or "premium required" should you use it. and the v6s DO have these stickers.

on the 4 cylinder, you should NOT use premium. if the car is tuned for a lesser octane rating, using premium can and will cause running problems.
plus youre just pissing away money for no benefit whatsoever. premium fuel has NO additional benefit other than resistance to pre-detonation.

[rawtunez]

i use half plus and half premium, is that bad?

[ChikagoGTZ]

Let me put it this way, I get 300-315 miles per tank with my V6. As a test, I tried running 87 instead of 93...and got 200 miles on that tank. It probably wasnt very good for my engine and I'm sure my ECU was going apeshit trying to compensate for everything. It's only an extra $4-5 per tank, and it's well worth it if you ask me. As Manybrews says though, only do this if reccomended or required.

[Serstylz2]

Damn I been running Premium in my i4 for a while now, I get much better mileage, should I switch back?

[galant_got_speed]

Damn I been running Premium in my i4 for a while now, I get much better mileage, should I switch back?

i keep hearing that using premium fuel in a car that isnt tuned or w.e for it can cause a shitload of problems, like timing and all that shit...i notice i get better mileage with premium but it could just be all in my head..i stopped using premium because of what i heard, but i go thru regular like friggen water...its ridiculous.

[S-Line]

ONLY PREMIUM HERE!!! I travel 120 miles per day, and when i used regular once....i swear i went thru a tank of gas in 1 day. Premium usually lasts me almost 3 days, that is of course if im not doing 90-100 up and down the Sprain Parkway

[rhema83]

My i4 has been running very well on regular. I am a chemical engineer so I trust the thermodynamics. Using premium fuel will just reduce efficiency and waste money.

[shiznit013]

In the V6, premium is a must. Your ECU has two different fuel maps, high octane and low octane, and it knows to switch between the two by sensing detonation problems. Since your car has a distributor, it can't retard the timing, so you just get more fuel.

[Xrs2]

Yeah my car runs like shit on low octane. I also found that if I run 92 + some booster I loose the vavle tick. Is that little bit extra octane going to hurt my motor at all? bc I really hate that valve tick.

I have an 02 GTZ with I/H/E+Relzo untuned. I also heard there was some additive in certain oils that get rid of tick. but I can't remember what it was.

[lonestar22]

i have an i4 running 87 and my gas mileage totally sucks. i still havent found the root of this situation

[ChikagoGTZ]

In the V6, premium is a must. Your ECU has two different fuel maps, high octane and low octane, and it knows to switch between the two by sensing detonation problems. Since your car has a distributor, it can't retard the timing, so you just get more fuel.

Interesting...

[manybrews]

In the V6, premium is a must. Your ECU has two different fuel maps, high octane and low octane, and it knows to switch between the two by sensing detonation problems. Since your car has a distributor, it can't retard the timing, so you just get more fuel.
that is completely incorrect.

the distributor has nothing to do with whether or not it can adjust timing. And of course, it can. You think its still using mechanical and vacuum timing control?
Of course not. its fully electronic, and retards when detonation is present.

[shiznit013]

I'm willing to admit I'm wrong on the timing issue, because the information I was basing it on was a general engine management system text, not application specific, but I am interested in knowing how it does function... please fill me in. I'd rather look stupid and learn, then be stubborn and ignorant. I was always under the impression that you dialed in the advance on a distrubted system by adjusting the position of the rotor cap, but after reading many of your posts manybrews, I'll take your word for it.

As for the fuel maps, I pulled that information from the Mynes thread on 3G, and I hope they aren't wrong, because I was really looking forward to that mod.

<div class='quotetop'>QUOTE(jaytech)</div><div class='quotemain'>High/Low Octane Fuel Maps:

The High Octane Map is stored in the ECU's memory. It runs more on the leaner side for a higher Octane fuel to give maximum performance. When the ECU is reset, it starts from the high Octane fuel map first upon start up. If the ECU is happy, and not getting detonation signals from the knock sensor it remains in the High Octane map mode. If it recieves abnormal signals from the knock sensor, then the ECU switches to Low Octane Fuel Map, which is richer than the High Octane Fuel Map.</div>

[manybrews]

<div class='quotetop'>QUOTE(shiznit013)</div><div class='quotemain'>I'm willing to admit I'm wrong on the timing issue, because the information I was basing it on was a general engine management system text, not application specific, but I am interested in knowing how it does function... please fill me in. Â*I'd rather look stupid and learn, then be stubborn and ignorant. Â*I was always under the impression that you dialed in the advance on a distrubted system by adjusting the position of the rotor cap, but after reading many of your posts manybrews, I'll take your word for it.

As for the fuel maps, I pulled that information from the Mynes thread on 3G, and I hope they aren't wrong, because I was really looking forward to that mod.

</div>
many things are altered during knock elination, the first and foremost being timing.
without getting too techincal, timing is 100 percent controlled by the ECM. the distributor is just an easy way to make sure the spark from one coil gets to 6 cylinders. other than directing the spark, its has nothing to do with when the coil fires. Thats dependant on a combination of crank position, cam position, throttle position, air volumn, temperature, and a dozen other variables.
Lets simplify. the computer is smart; Its knows by cam and crank position when a car has number one cylinder on top dead center. dependant on all those factors, lets say it decides to fire the coil 20 degrees before TDC. It knows where its at from the previously mentioned crank sensor and cam sensor, so it fires 20 degrees before it hits TDC. The distributors job is to now just make sure it gets to the correct cylinder, and nothing else.
on every V6 since 04, the cars have had coil on plug ignition, so there are actually 6 coils, but the math isnt any different. It still needs to fire a coil 20 degrees before TDC, but now it has to fire a specific coil rather than a single one.
If there is knock present, the ECM fires that coil later and later until the knock is eliminated. It can go as far as 5 degrees AFTER top dead center.
Obviously, this is incredibly simplified, but you get the idea. There are a hundred factors that determine when the spark is fired, and its changing constantly. These cars do not idle at a preset mark; I.E they dont idle at 7 degrees before TDC, but rather bounce around with each individual firing of the coil. so actual timing at idle could be 5, 7, 9 degrees (etc.etc) and change with every revolution.

[furiousgtz]

i always put preimum in my gtz

[shiznit013]

<div class='quotetop'>QUOTE(manybrews)</div><div class='quotemain'>
many things are altered during knock elination, the first and foremost being timing.
without getting too techincal, timing is 100 percent controlled by the ECM. Â*the distributor is just an easy way to make sure the spark from one coil gets to 6 cylinders. Â*other than directing the spark, its has nothing to do with when the coil fires. Â* Thats dependant on a combination of crank position, cam position, throttle position, air volumn, temperature, and a dozen other variables.
Lets simplify. Â*the computer is smart; Â*Its knows by cam and crank position when a car has number one cylinder on top dead center. Â*dependant on all those factors, lets say it decides to fire the coil 20 degrees before TDC. Â*It knows where its at from the previously mentioned crank sensor and cam sensor, so it fires 20 degrees before it hits TDC. Â*The distributors job is to now just make sure it gets to the correct cylinder, and nothing else.
on every V6 since 04, the cars have had coil on plug ignition, so there are actually 6 coils, but the math isnt any different. Â*It still needs to fire a coil 20 degrees before TDC, but now it has to fire a specific coil rather than a single one.
If there is knock present, the ECM fires that coil later and later until the knock is eliminated. Â*It can go as far as 5 degrees AFTER top dead center.
Obviously, this is incredibly simplified, but you get the idea. Â*There are a hundred factors that determine when the spark is fired, and its changing constantly. Â*These cars do not idle at a preset mark; Â*I.E they dont idle at 7 degrees before TDC, but rather bounce around with each individual firing of the coil. Â*so actual timing at idle could be 5, 7, 9 degrees (etc.etc) and change with every revolution.</div>

It took me a while to get what you were saying, but it finally clicked. Thanks for the info... very useful.

My ignition coil went up at 39k (3k past warranty), and I had to buy a whole new distributor just to get the coil. Why does Mitsu not sell the coil separately (or do they, and I just got scammed)?

[manybrews]

<div class='quotetop'>QUOTE(shiznit013)</div><div class='quotemain'>
My ignition coil went up at 39k (3k past warranty), and I had to buy a whole new distributor just to get the coil. Â*Why does Mitsu not sell the coil separately (or do they, and I just got scammed)?</div>

They do not sell it seperate. Most car companies with combined coil/distributors have never sold the two seperate.
Its a production thing... Mitsu just builds the whole thing to ship to its multiple factories worldwide. If its an all-inclusive unit, theres less to worry about.

Coil failures on mitsus are a rarity. You just got unlucky, I guess.
In your case, I woulda bought a used distributor to save a few bucks

[shiznit013]

<div class='quotetop'>QUOTE(manybrews)</div><div class='quotemain'><div class='quotetop'>QUOTE(shiznit013)</div><div class='quotemain'>
My ignition coil went up at 39k (3k past warranty), and I had to buy a whole new distributor just to get the coil. Â*Why does Mitsu not sell the coil separately (or do they, and I just got scammed)?</div>

They do not sell it seperate. Most car companies with combined coil/distributors have never sold the two seperate.
Its a production thing... Mitsu just builds the whole thing to ship to its multiple factories worldwide. If its an all-inclusive unit, theres less to worry about.

Coil failures on mitsus are a rarity. You just got unlucky, I guess.
In your case, I woulda bought a used distributor to save a few bucks</div>

Well I'm glad it is a rarity, because it seemed like a kick in the pants to be so close to warranty and spending so much money. When it died, I was 20+ miles away from home, and finding a used one was low on my list--I just needed my car back home and functioning. It was odd, because there were absolutely no indications of failure. It ran perfect the night before, and the next day it wouldn't turn over. Mitsu almost lost my business on that day... now I'm more borderline.

[shadow83]

I just bought a 2002 ES V6 w/62K miles and am on my third tank of gas. I figured the premium sticker was bunk and filled with regular. First tank was a little over 24MPG (90 highway miles). Thought it was a little low. Also there is a slight miss from time to time and I just assumed that it needed plugs, wires etc.

Today after filling up I was sitting in line for the car wash and it started idling rough (was in N) so I tapped the throttle figuring the engine was loading up. It hesitated and about 2 min later the "service engine soon" light came on. Since is was a little over 60K I thought it was just a time maintenence signal. Now I think that it may have just been the engine not liking the regular.

I'll fill up with premium for the next few tanks and check the milage. Thanks all.

[manybrews]

I just bought a 2002 ES V6 w/62K miles and am on my third tank of gas. I figured the premium sticker was bunk and filled with regular. First tank was a little over 24MPG (90 highway miles). Thought it was a little low. Also there is a slight miss from time to time and I just assumed that it needed plugs, wires etc.

Today after filling up I was sitting in line for the car wash and it started idling rough (was in N) so I tapped the throttle figuring the engine was loading up. It hesitated and about 2 min later the "service engine soon" light came on. Since is was a little over 60K I thought it was just a time maintenence signal. Now I think that it may have just been the engine not liking the regular.

I'll fill up with premium for the next few tanks and check the milage. Thanks all.
it's definatly not "bunk". the engineers placed it there for a reason, and I HIGHLY recommend you stick with the premium, lest you suffer a decrease in performance and possibly milage.