Phil8616

iTrader: (11)

Hey all, I guess this is where to post a "basic tech ?", but heres a quick dumb question....I just got my car dynoed and I just remembered I had put in Mid Range, since the weather has been getting cooler and its 10 cents cheaper. So did that affect the dyno run at all?? My numbers are in the sig..any comments and answeres are appreciated...thanks

-Philip

Luna

iTrader: (6)

Common sense says probably

Phil8616

iTrader: (11)

well ya common sense would be yes, but I wanted to know if it made any real difference like more than a hp or two compared to using 93 Octane. Just wanting to know how much of a factor using mid range is to using 93.

Patman

You probably lost about 3-4hp due to knock retard.

dailydriver

Hell, I would NEVER put anything less than BP/Amoco 93 in my baby, even in the dead of winter! But we're lucky here in Joisie, to have 93s as well as Sunoco Ultra 94 available. BTW you should always tune with the fuel you plan to run your best with, and then stick with it if you got an "edgey/no leeway, on the limit" type tune.

BlueSix

I love it when people put anything lower than 91 in cars that specifically say "premium unleaded fuel only."

paper doll

iTrader: (7)

my question is why? why would you even put low grade fuel to have your car dynoed? seems like a waste but thats just me i guess

Ace$nyper

iTrader: (8)

That low?
I was given the impression it was higher like 10-15 ish almost.

Somthing I remember in an old car craft.

I could very well be wrong but yes the knock retard will sap some power.

mpe488

It depends how much your car had to retard timing to get rid of knock, since it's supposed to run on premium it'll probably take away some power.

And Bluesix, apparently you've never been in desperate need of money. You can save a bit by putting lower octane into your car for awhile, sure you'll lose horsepower but when times are tough you do what you gotta do. And you can always put premium back into it and you'll be running the same as you where before.

And, Paper Doll- as for purposely putting mid-grade in it to get in dyno'd, that doesn't make much sense. But if you read the post carefully- he remembered that he put midgrade in it AFTER he got dyno'd. So yeah, we all make mistakes I guess.

mattkimsey

My owners manual says use 91+ octane for best performance, but 87 can also be used.

paper doll

iTrader: (7)

ok 488 i guess i just think of the car istead of trying to be cool on paper, and i would never overlook a thing like that.... oviosly he wasent to short on cash if he was taking his car to get dynoed, putting lower grad fuel in your tank is fine if you have to (and lets think of this logically you get worse milage on lower grades so in the long run putting anything less than 91 would end up costing more) but just trying to cut corners so you can afford something that you just want to show off?

ZeeQuick

iTrader: (2)

Isn't the mid-grade stuff usually just 10 cents cheaper than premium?? So you're gonna save what......a buck, maybe a dollar fifty?? I understand times being tough, but I would think you could cut corners elsewhere and save more than what you'd save by switching octanes.

Roarin_8

iTrader: (5)

I agree, instead of putting 20 dollars of midgrade stuff, put in 10 dollars of premium. Save 10 dollars

OOZ28

Thank you!! You gotta pay to play.

davered00ss

iTrader: (4)

Lower octane will most likely cause detonation which should be more pronounced at higher RPM's. This will cause Knock retart, which retards the timming, lowering your horsepower. So the answer is yes.

BlueSix

I can think of many better ways to save the $1.50 you save each week by putting mid grade into your car.

bigradical

iTrader: (3)

If you really think about it, our cars have 16.8 gallons tanks. You figure if you spend 20 cents more for premium, that's only a little over 3 dollars in difference if you fill up with it. Why not just run the good stuff anyways?

Phil8616

iTrader: (11)

Alright well I believe I learned my lesson about putting midrange in. I dont usually do it at all, but was told that in colder weather midrange can be used if you arent doing any racing or high RPM driving. I only took it to the dyno because they just opened a new shop and had a one day special charging 40 bucks for 2 runs. But anyways thanks again for the help to the people who didnt bash me for making a mistake and answering my questions.

-Philip

davered00ss

iTrader: (4)

You can get carbon build up even in coler weather using lower octane fuel. Good way to ruin an engine.

NHRAMAN

iTrader: (1)

If u keep it under 3500 rpm with 87,there should not be a problem...that is what my mechanic/friend/race car owner/driver says...low rpm's have little or no affect on harming a OBDII equipped vehicle.I use 91 - 94 octane myself..