ddawg23213

No this isn't a do I need to run premium thread.

I was just wondering how much power is generally lost if you were to run mid grade or regular in an ss. I would never do this, I know the car is tuned to run on 91, what I am curious about is how much power cars typically gain when increasing octane.

For example, say the car is making 240 on the dyno with 91, what would you expect the numbers to look like for 89 and 87 octane gas?

Whitnith

iTrader: (2)

I believe it's not so much a horsepower thing, as it is a you will get engine knock and your engine will break thing.

BLAZIN07SS

iTrader: (7)

depends on the vehicle and how much timing advance is increased. each car is different. there is no real "calculation" for this

emiller

Its not going to cut your power by a set % or something. Every engine will react differently because they are tuned differently. Ford claims their 5.0 loses 10 hp (~2.5%) but its also tuned safely to run on regular if thats what you feel like using. An LSJ may lose 5% (I'm making that up). Get some of the stage upgrades or a tune and it probably needs to run premium or it will knock and break something down the road.

06SS ALL DAY

its rather you run 87 or 93. anything in between doesnt differ from the other i.e. 89-91.

BLAZIN07SS

iTrader: (7)

or just keep filling up with premium. we are talking about a $4 difference at fill up at the most.

06SS ALL DAY

hey man that 4 bucks can go towards a pack of cigs or a shot of makers mark

matte454

Your motor will not knock from lower octane gas... there is a knock sensor that will detect any detonation before it puts your engine at risk, it will retard the timing and or richen the fuel mixture. This will give you Lower HP and worse MPG. Also most brands of supreme dont have ehtnaol so your better off there too as ethanol has a lower energy content then gasoline.

Achilles

This is bad information.

If you are running an SS 91+, 91 and 89 have a HUGE difference. The moment 10% heptane comes into play is when the oxygen levels really start to differentiate. It is 91 and 93 that are hardly noticeable (unless one has higher ethanol blends).

You NEVER want to run 87 in ANY SS Engine, what so ever.

It is not just timing in the spark plugs which increases acceleration but it is engine knock which you can blow your engine if you run a high enough amount of heptane.

Kolt

even with the knock sensor and all the precautions the com can compensate, running a lower grade fuel in a car thats made for 91 WILL make it knock at some point. Knock=Killing your engine. stick to premium. if you want to run 87, get tuned for it(if its possible), or you will run the risk of burning a vave or hole in the piston, thats if you get lucky