Leon993

Ive been using regular and have no knocking, no pinging or anything that would indicate Im using the wrong fuel type.

My car is OBD1, could that be why its more compatible w less octane fuels?

I put some Redline fuel injector cleaner once a year just to be on the safe side

hkspwrsche

Premium for me and not sure you'd hear the pinging. You just cruise most of the time?

slickster85

What is the reason for running regular?

vincer77

I accidentally put regular in once and she started pinging a mile away from the station. Ha d to Stop at auto parts store and buy an octane booster.

P-daddy

Leon- how has this affect your mileage?

Stuttgart951

Good gas is cheap insurance.

justin-in-athens

The 964 and 993 both have knock sensors, and should not ping on regular fuel of at least 87 octane. With that said, you will get improved fuel economy by running the premium grade--whether the difference in economy will outweigh the additional cost is another story. I am sure I will get flamed for not recommending you run premium all the time, but I usually alternate between the different grades depending on the price. Sometimes the price spread just doesn't makke sense.

TMc993

I use premium all the time and look at it like this:

• I drive my 993 roughly 9,000 miles per year.
• If I get only 20 MPG (I get better, but I'll use 20 to simplify the math), then I purchase roughly 450 gallons of gas per year.
• With a $.30 per gallon difference between regular and premium, this means that buying premium all the times costs me roughly $135 per year more than buying regular all the time.
• That comes to roughly $11 per month. If premium does indeed deliver better mileage, then the per month cost is even lower than $11 per month.

Personally, I can absorb the $11 per month in exchange for more power and a lessened chance of some unintended engine damage when a knock sensor doesn't pick it up in time.

YRRMV...

Terry

Steve Weiner-Rennsport Systems

I tell my clients to follow the factory's recommendations in the owner's manual.

Detonation thresholds in air-cooled engines are NOT static; they change with outside air temperature and the DME has a limited range that it can pull out timing to accommodate less-than-optimal fuels. Six degrees is the limit and one can watch the engine struggle with poor fuel by watching knock-sensor activity in real time with the Porsche scan tools (Hammer or PST-2).

Unless you open up engines for a living and see the effects, Caveat Emptor on using fuels less than 91 (R+M/2) octane.

mdude

This subj has been discussed ad nauseum. It always comes to this:

1) For those who baby their car, it's nothing but the best.
2) For those who hesitate about potential damage, they usually opt for premium.
3) For those on the fence, if it pings, switch. If not, go regular.
4) Cheapies: go regular and cover their ears.

Further debates are futile.

LexVan

Silly logic.

You won't use the best (91 or 93) fuel vailable, but, you'll add Red Line fuel cleaner yearly "to be safe".

GT3 Tek

+1 on what Steve said! I've seen inside a 3.6L case that only ran 87 and it wasn't pretty.

Team GT3 Tek

ca993twin

At today's fuel prices, the difference between premium and regular is 20 cents/gal, which works out to a small, 5% difference. This seems like a silly small amount to attempt to save (and with the potential of higher fuel mileage with the premium, perhaps no savings at all?) with plenty of good reasons to use the better grade. Follow the manufacturers recommendations on this.

aribop

I drive mine every day and always use premium fuel. I will absorb the cost difference to ensure the car is running as it should and to avoid problems down the road.

H.H.Chinn

Nothing but the best for this car!!