porscheforfun

I have a stupid question , but where I live they only sell 91 octane do I just use a octane boost to get to the recommended 93 or is it must use 93 octane . Ive only had my turbo for 3 weeks

Dock

91 works. Not as well as 93, but 91 isn't going to hurt your engine.

ron.eddy

Have you posted pictures of your 996 yet? I have been intrigued since I saw your post when you bought it because that is a great price for what I can only imagine is a great car having only lusted after one up to this point. Some day... Anyway as for your question I am interested in the answer as well. I have a 944 turbo and whenever I get gas at a 91 only station I end up buying octane booster just because I feel wrong if I don't haha. Maybe if it wasn't a turbo but I have a feeling that 93 recommendation is there for a reason ya know?

Dock

It is not a must.

porscheforfun

I have not posted pictures . To tell you the truth the only reason I havnt is because I havnt had good pics. always taking pics with my droid thunderbolt . I need to post pics. I will wash and wax and post pics.

LVDell

Those octane boosters you pick up at AutoZone, etc, only boost one thing.....your departing of hard earned funds. Multiple studies have been done showing that they show absolutely no significant octane boost. And no, 91 won't hurt your car. It is perfectly acceptable and is specified as allowed in your manual. If you want to run 93 then find a station that sells 100 unleaded race gas and do a 1/3 100 to 2/3 91 mix and you'll get you 93 (technically 94). To much hassle in my opinion.

Kevinmacd

Your knock sensor has enough lattiude to adjust for a few points. You vehicle will not have max performance, but either way, I would stay away from the octane boosters. Lot of octane boosters post petroleum distilates, which in essence is acetone. Stay with raw pump gas.

Macster

Welcome to CA and its crappy gas.

I've run 91 octane for years in my Boxster and since 09 in my 03 Turbo (and the previous owner since 03 when he bought the car new) and neither car has suffered any I can tell, other than deliver slightly less gas mileage.

Once in a while out of state I get to put some 93 or even 94 octane in the car and sometimes I think or at least imagine the engine perks up some in response to the higher octane gas.

But here in CA... 91 is all she wrote.

'bout all you can do is buy a name brand (top tier) gas and buy from a busy station to avoid possibly getting stale gas.

Sincerely,

Macster.

herman maire

Another question, when you go to the gasoline pump ( the pumps that have 4 different gasoline grades all pumping through 1 line) .

Say the last grade that was pumped was regular gasoline then you select 94octane. Is the line still filled with regular gasoline even though were paying for 94octane .

Just wondering

No HTwo O

I've wondered about this too.

Kevinmacd

Good question, from what I have read the petroleum institute says about 1/3 gallon is left in the hose. So in essence there is a possibility of getting some other octane than the one selected. Not knowing where the meter actually collects the data of pumped fuel, it's hard to tell if you really are paying for the lower grade fuel, when pumping higher octane.

SSST

Assuming 12 gallons per fill up and the person before used 87 octane, that would take 93 octane to 92.67 octane.

You probably wouldn't notice the difference.

If you can ever find gas with no ethanol, that really wakes the car up. Occasionally I stumble across it in rural areas.

Dock

Probably?

You're being generous.

Dock

Are you concerned because of the potential reduction in octane, or because you're not getting everything you paid for (or both)?

Macster

In short yes. The hose is still filled with whatever grade of gas was pumped before.

It makes no difference given the number of gallons of gas the tanks of our cars' hold. For instance, I filled up my Turbo today: 12.246 gallons.

In the case of this fillup today, even if one gallon of 87 octane was in the hose, the octane rating is diminished from 91 to 90.673. I dare say the difference in performance between fresh and stale 91 octane is greater.

Now then: In some motorycycle magazines (especially in the UK) I've read reports by some writers/riders that some models of motorcycles with small tanks due suffer some from the presence of lower octane gas in the hose.

Anyhow, if you're concerned when you pull into a station pull up behind a car that is filling up with premium so when you pull forward to fill up you get no 87 mixed with your 91 or 93.

Sincerely,

Macster.