fuel

bigz

Member
can some please tell what gas i should use regs,plus,prem. im a new owner pf a mp5 and i was just wondering thank you
 
I've always used premium in all my cars. Mostly for a piece of mind but I seem to get less knocking with premium fuel. I try to use Shell whenever possible. I used GetGo a couple times to use my Giant Eagle feul perks discount and my car didn't seem to like it as much. But I've got an MP3 ECU that is rather picky.

I personally just prefer not to put any "cheap s***" in or on my car, no matter what it is. But that's just me.
 
The P5 will do just fine on regular gas. If you swap the ECU to an MP3 or MSP ECU then you will need to run premium. I've been running costco Regular for the past year with no problems averaging about 28mpg. I've put in premium a few times and never noticed any difference. My car is bone stock by the way.
 
The P5 will do just fine on regular gas. If you swap the ECU to an MP3 or MSP ECU then you will need to run premium. I've been running costco Regular for the past year with no problems averaging about 28mpg. I've put in premium a few times and never noticed any difference. My car is bone stock by the way.

+1. The MP3 ECU requires 93 octane because of the higher compression ratios. But using anything higher than 87 or 89 octane in the regular P5 is just wasting money, regardless of what you may think about "using the cheap stuff".

IMHO, if you have to use higher octane in any case besides the MP3 ECU to prevent knocking, you've got some major timing issues that you need to deal with.
 
E10. Typically 89 octane here so it has higher knock resistance than 'regular', 87 octane. I have used E10 for the past 15 years with no ill effects.
 
Yeah- I knew I shouldn't have mentioned the MP3 ECU, that will just confuse people. Exclude the info on the ECU.

You can run whatever fuel you like in a stock P5 and of course it will still run well.
 
I tend to use the "big" brand gas stations, they will have the cleanest gas. So Texaco, Shell, Chevron, etc and you can't go wrong. As far as octane level, 87 if you're not on an MP3 ECU.
 
every car ive owned ive had to use premium. you shouldve seen my face when i pumped in 87 for the first time in like 5 years. i had that grinch smile going on. 87oct is best. no need to go higher
 
+1. The MP3 ECU requires 93 octane because of the higher compression ratios. But using anything higher than 87 or 89 octane in the regular P5 is just wasting money, regardless of what you may think about "using the cheap stuff".

IMHO, if you have to use higher octane in any case besides the MP3 ECU to prevent knocking, you've got some major timing issues that you need to deal with.

i don't see how adding an mp3 ecu will up your compression ratio(ugh)


The P5 will do just fine on regular gas. If you swap the ECU to an MP3 or MSP ECU then you will need to run premium. I've been running costco Regular for the past year with no problems averaging about 28mpg. I've put in premium a few times and never noticed any difference. My car is bone stock by the way.

well if your using a MSP ecu you must be boosting

*as for the original question.... i think the majority will advise regular gasoline 87oct
 
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You're throwing your money away...

That's a bold statement. What proof does anyone have that higher octane fuel is a waste of money? We've all seen the dyno charts of high hp cars running on 91 then 93 octane get more power from the higher octane. Of course, I know my car isnt high power, but still. Not to flame, I just would like to know why some people are so against premium fuel?
 
^Because it simply isn't needed for our cars. You might end up with a tiny bit better fuel economy, I have no idea if you would, but the cost would likely balance out. You might end up with a little more power, but really are you going to feel that extra 1 or 2 hp in your regular driving? Probably not. High HP cars are probably running much higher compression ratios where that extra resistance to burning allows for more boost and/or more aggressive timing, where it is important. Except for the MP3 ECU swap our cars aren't going to be massively changing the timing.

Stick with what the manual says, go regular.

If running premium makes you feel better go for it, but on a 7 or 8 year old economy car it isn't necessary.
 
I get significantly better gas milliage (3 - 4 mpg) on non-ethenol fuel.
When the P5 was new I monitored 87 & 93 octane usages. Got a couple MPG better on 93. Doesn't make sense as compression ratio isn't high enough that it should make a difference. Certainly doesn't give back milliage for the extra cost. Nonetheless, I generally run 91 non-ethenol.

Found a station that has 93.
P5 definitely seems to accelerate faster, and even sound a bit louder under acceleration. Shouldn't make a difference, but seems to. Go figure.
 
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