djlod

I always use premium gas (91 octane), but I spoke with a few friends and they use 87 octane gas in their 997s and 996s.
What type of gas do you use?
Is it a bad idea to use 87 or 89 octane gas in a 997?
Thanks.

rijowysock

use 93, we dont have 91 here.. only 87/89/93

i know the car is setup not to knock, but i wouldnt run 87 in car ever.. maybe 89 if mixed with 93 to make 91 if they didnt have 93.

Clifton

Shell 93 and nothing else for all 2,500 miles thus far.

Fahrer

I use only Shell 93 octane. 3,200 miles so far.

ADias

If you need to save on gas type, you cannot afford your car. In CA only E10 91 is available, but I would buy 93 if available.

Minok

Use premium, whatever grade it is (91 I think is what I can get here). I'd use lower only if nothing else was available. Its possible to run on less, but why? You could also have purchased a lesser tuned car.

keenan9

Only Shell 93 for me.

No HTwo O

Friends don't let friends drive with <91-93.

I only use 93. From a named brand (Shell, BP, Mobil, Chevron) and a busy station (fresh).

Macster

You need to upgrade your friends.

Now assuming there's nothing in the 997 owners manual that cautions against using 87 or 89 octane gas *ever* in a 997, using 87 or 89 octane gas in a 997 Porsche is not the end of the world.

It is not the best thing for it though. I don't have time to cover all the bases but almost certainly the money these people are saving up front at the pump is being lost as they drive their cars from poorer gas mileage and possible increase in engine deposits.

Lastly to avoid detonation under some operating conditions the engine controller will have to retard the ignition. This lowers the max. pressure developed inside the combustion chamber/cylinder which of course helps prevent detonation -- good -- but raises exhaust gas temperature -- bad -- which of course subjects all parts exposed to exhaust gases to higher operating temperatures increased degradation and possible engine damage.

Ask your friends if they're banking their fuel savings money to pay for an out of warranty burned valve repair?

Sincerely,

Macster.

red frog

I only use Premium, and here in California only 91 is available. But once or twice a month I mix pump 100 race with 91 to blend out to 96 or so. I also am a big fan of Shell oil product's, But have been using Cheveron as of late, And I swear I feel a slight difference.

ADias

The common wisdom is that Chevron gas w/ techron is better than Shell Gas. Do you think Shell is better. Some also like 76.

REBor8

Shell or Chevron. 91 in Cal. and 93 when available out-of-state. I haven't found any states that don't do the 10% blend. More political bull**** crammed down our throats by our all-knowing gov't.

todd.

same here

No HTwo O

I saw some 91 Octane "Recreational Gas" without alcohol a few weeks ago in Northern Wisconsin. I just wish we could buy 100% 93 octane gas.

No HTwo O

This is always such a silly issue, if you look at the numbers:

10,000 miles driven (this is high for most)
22 miles per gallon average (this is low for most)
455 gallons of fuel
$0.30 upcharge for 93 octane

Yearly operating cost increase over 87 is only about $136.00.

That's a cup of Starbucks per week.