What octane do you use?

[FLSilverP5]

I was just wondering what type of gas do you guys put in ur p5's? As the mods go up, so u use higher octane gas? I've been told if i put anything but 87 i am throwing away my money. All my life i've heard that changing the gas octane in the middle of the car's life was really bad for the car. Any opinions or has anyone done this?

 

[Khoifather]

I was just wondering what type of gas do you guys put in ur p5's? As the mods go up, so u use higher octane gas? I've been told if i put anything but 87 i am throwing away my money. All my life i've heard that changing the gas octane in the middle of the car's life was really bad for the car. Any opinions or has anyone done this?

Hey, do a search on it, we had a thread about this a while ago, and alot of people posted their opinions. If I can find it, I'll post the link for you.

 

[jersey_emt]

Unless you turboed your P5 or are running something like the FS-ZE engine, all you need is 87 octane. Going higher will probably reduce gas mileage and performance.

 

[Khoifather]

Here's the Link

 

[Gbourdon]

Doh. I dont have a P5 (freak)

 

[stdntDrvr]

i use 91...only because i run a mp3 ecu.

 

[seth]

shouldn't even matter much with that I think you would find the medium just as good for you

 

[Masshole]

I was just wondering what type of gas do you guys put in ur p5's? As the mods go up, so u use higher octane gas? I've been told if i put anything but 87 i am throwing away my money. All my life i've heard that changing the gas octane in the middle of the car's life was really bad for the car. Any opinions or has anyone done this?

Here's the skinny on octane. Octane has one and only one important effect on your car: it makes gas more difficult to ignite. This is important in a few situations:

1) If you have advanced the timing of your car a higher octane rating can help prevent premature ignition or detonation

2) if you are running a turbo or supercharger in your car, a higher octane can again help prevent detonation or premature ignition.

It does not improve fuel economy; if anything, it will decrease your economy and probably decrease your performance on our cars.

So... until you've turbo'd your car or changed out your cams with something a little more agressive; save your money at the pump.

 

[stdntDrvr]

well...mazda recommends premium fuel on the mp3 due to ADVANCED TIMING...and i also have HARDER CAMS...so, if i run regular, i'll get a knock...and i'm not going to risk my motor over .20 cents a ******* gallon.

 

[Masshole]

well...mazda recommends premium fuel on the mp3 due to ADVANCED TIMING...and i also have HARDER CAMS...so, if i run regular, i'll get a knock...and i'm not going to risk my motor over .20 cents a ******* gallon.

Out of curiosity, how did you get the MP3's PCM in your p5? i've been thinking of doing the same with mine.

i.e. if you had the dealer flash it, how much arguing did it take to get the new pcm in there, and what was the trick to get them to agree to it?

 

[stdntDrvr]

well, i bought an ecu from a mp3 owner...it's located under a steel plate in the passenger's floorboard...i just switched them out. if there's an mp3 owner near you, you can have a dealer download their ecu into their WDS and flash it to your car...there's a tech at our dealership that's pretty cool that'd do it...it all depends on the dealer/tech you talk to.

 

[P-Funk!]

Is there another step after i buy a MP3 ECU? I thought i just swapped the box and drive away (quicker)

What if i don't get it 'flashed'?
T'anks.

 

[stdntDrvr]

yeah, you can do that...or you can have a dealer download the ecu off an mp3 into their wds and flash it onto your car...if you can find a dealer willing to do that, of course!

 

[mp5jeff]

Is there another step after i buy a MP3 ECU? I thought i just swapped the box and drive away (quicker) .

the 2whp you will gain won't make the car much "quicker"...

 

[stdntDrvr]

exactly. but it all adds up in the end.

 

[II-Savy]

I run 93 octane with a jolt of booster. Prolly runnin' around 95 or 96. MSP pushing 9.5 PSI.

 

[protegeV]

I run 93 octane with a jolt of booster. Prolly runnin' around 95 or 96. MSP pushing 9.5 PSI.

I b'lieve this is the P5 forums, and thus the poll is directed towards P5 owners only

btw, i use diesel (rofl)

 

[uclap5]

people never follow directions.

 

[II-Savy]

Yes now I see the P5 reference. Sorry I ventured out to where the slow cars are. (crazy)

 

[rustychops41]

I was just wondering what type of gas do you guys put in ur p5's? As the mods go up, so u use higher octane gas? I've been told if i put anything but 87 i am throwing away my money. All my life i've heard that changing the gas octane in the middle of the car's life was really bad for the car. Any opinions or has anyone done this?

I don't know if it's a Mazda thing or what, but every Mazda I've owned (several B2000/B2200 P/U's, a 626, several Proteges) will ping on 87 octane only in the summer w/ the AC on. The summers here (Central Calif.) are pretty hot (100-113F) and I guess it's the load on the engine. So I can run 87, but must use at least 89, if not 91 in summer. 91 is as good as it gets here in Enviromental Wacko Land.