StanThePorscheFan

Has anyone tried running DFI engines on higher octane 98 or 101? Track day comming up. How does it affect the car from any perspective? Thanks.

No HTwo O

Save your money. Use good 93.

Nugget

The only improvement you'd get from 98 or 101 octane would be from the weight savings resulting from your thinner wallet.

StanThePorscheFan

Wow. I am surprised. No benefits at all?! How about 110 octane?

RollingArt

Porsche designs and builds the engines to run on 93. Just run it.

110 octane will probably lose power because it's burning too slow to get complete combustion in this engine.



Phil

rijowysock

if car was tuned for it, yes. otherwise your performance is better on the 93, worse on the 101/110.. friend who is a big engine/tuning guy was telling me that you want to run the lowest you can for your tune because it explodes faster or something.. he explained it for an hour and i still dont remember the specifics...

StanThePorscheFan

I just mixed 5 gal of Sunoco's 94 and 5 gal of 110 octane fuel. Absolutely no difference in power. BUT, the engine runs like a clock: no ratling or knocking. Very very smooth through entire range. Otherwise, all the same. It makes sence that in order to get full benefits from this fuel, one must tune the car for it. Anyway, now I have 12 galons of this crap.

rijowysock

shoulda read the replies before filling..

car will run worse on the gas you chose because it explodes slower, luckily the car auto does everything to prevent problems

mdrums

Higher Octane DOES NOT give you more power. A higher octance fuel is LESS volital so it will not ignite before it is suppose to. You car was tunned to run 91/93 octane. A higher octane will provide no benefit.

Dave07997S

The car is tuned for 93 octane..however, you can run as low as 90 octane but you do lose power. In fact when you open the fuel door on the car it even says that 93 octane is the minimum.

I run 105 F&L in my car, but thats just to get the octane up to 93 as here in Kalifornia we only get Coors **** water for fuel. I have seen as much as 8-11rwhp just from 91 to 93 octane. I blend in 3 gallons of 105 unleaded to 13 gallons of 91 **** water to get me to the magic 93 octane..well actually 93.5

Dave

Dave07997S

First off I read in an article that the 997s are designed and rated with thier horsepower ratings at 93 octane, and in fact will see a midrange tq. boost with octanes up to 95. Anything above this is going right out the tailpipe. If you run different software that has the ignition timing come in sooner then you will see results running higher than 95 octane in the car.

As I said in a previous post...if you are in an area of the country that doesn't sell 93 octane (most of the west) as we only get 91 out here and in Ca. it isn't even a good 91 octane, then running a few gallons of race gas can help as you want to get the octane up to the 93 octane mark. Also, race gas has other properties in it besides higher octane that helps in horsepower production. Its flash point and other properties help in this as well. I saw a post where an owner of a 997S ran straight 100 octane in the car and his car gained 13rwhp over 91 octane. As I said before 91-93 octane can be worth by itself of 8-11rwhp. Its not someting you will feel in more pull, but the car will seem to be chomping at the bit more and the throttle response will be better as the spark is coming in sooner and the timing isn't being retarded.

Dave

StanThePorscheFan

thanks a lot for the info. Tank is empty now. I will try adding just a bit. See what happens. Probably not much.

Wills

Euro spec 997's are designed to run on 98ron fuel all the performance stats are based upon using that fuel the manual states that using 95ron fuel will lead to a reduction in performance.

Not sure whether the octane ratings are the same in the UK vs the US?

Nugget

US and UK octane ratings are not the same.

http://en.wikipedia.org/wiki/Octane_...en_RON_and_AKI

Wills

That will be it then!