Radmd74

For turbo 997s, it is recommended to use octane 93, but some states have only up to octane 91. What gas octane levels Are folks normally using? If using 91, do you supplement the fuel. Not planning to race or mods, just want to give the car the right gas formula.

If you drive sparingly (less than 100 miles per month), how much time between refueling ( empty and refilling the gas) is optimal? Is it 1 or 2 months? Or less?

If this has been answered before, don't flame this thread. Just wanted to get some opinions and experiences from turbo owners.

Carlos4S

Kevin

Datalog your knock retard. If you have access to unleaded race gas. Use a few gallons per tank..

atcbi5

Gonna start using 90 100% gas. No ethanol. Wonder if my performance will go down?

Kevin

90 octane will knock like no tomorrow in Florida heat. I bet you that it will max out the knock retard (minus 15 degrees)

MachZ990

I’ve been taking data logs for a well-known tuner, Emre. My 2012 997.2 TTS seemed to run fine to me on 91 non-ethanol and I filled up with it frequently. After a few data logs were analyzed it was apparent that my knock sensors were quite active running 91. I switched to 93 ethanol fuel and I have no active knock sensors. My car is much happier and gives full performance on 93 but retards timing with 91.

1q2w3e4r

@Kevin I slurp VP 109 race fuel into my cars when I run at the strip or track as you know being 60:40 98RON/VP109 in my 996TT and 50:50 split in the 997.2TT

I've seen last time I was picking up my race gas at $12 odd a litre ($225 AUD for 5 gallons) that they also stock something called Octanium by VP https://www.vpracing.com.au/products/octanium-case-8

Its a mix that gets added to a tank of pump fuel, have you had any experience with it or seen any logs? It's much cheaper than running a straight mix of race fuel and pump fuel $30 per tank of fuel, but ultimately and extra $225 per track day is cheap insurance in the big scheme of things so I've never run it.

atcbi5

Oops, will stay at 93 then. Thanks guys.

Radmd74

Where can I get this 93 octane in los angeles? If not, then what mixture can I do with the 91 octane?


QUOTE=atcbi5;15827507]Oops, will stay at 93 then. Thanks guys.[/QUOTE]

Kevin

You will need to find a gas station that has 100 octane unleaded at the pump. You will need 5 gallons per tank of 100..

Radmd74

So to be clear, get the gas to "empty" then fill it with the 100 octane pump first then fill the rest with 91?

Noob here with the gas. LOLs

Kevin

Run it down to the reserve light, then fill 100 (5 gallons) top up with 91..

Radmd74

Do you do this with every fuel up?

Better for overall health of the engine?

cjcam930

FWIW I've been doing this for several years, blending around 1/4-1/2 tank - have 100 pump nearby - running a Cobb OTS Stage2 93oct tune with no issues thus far. It does get spendy at $9+/gal but I drive this car very low miles.

makoshark72

91 all day...last weekend I drove from Telluride to Seattle, 1226 miles, nonstop....20 hrs. We put 2966 miles on the car in 8 days. 91 octane the whole trip..2008 turbo...stock...