What kinda gas do you use?

[ERAU944]

haha, i know avgas is leaded, thats why i was using a gutted cat at the time. i may be dumb sometimes, but i'm not retarded!

by the way, this was a year or two ago, and my car is still just fine. the increase in octane must have offset the lower specific gravity. i never noticed any pinging while using the avgas, only that my car smelled like a cessna.

[Chriz75]

I run on 98 octan. I bought a perfromance chip so I changed from 95 to 98. I have a 944 S2.

[auh]

Wow, I forgot I started this thread...

[Ferrara_racing]

Don't know if it's been covered but drop a 104+ into your next tank and enjoy....Makes a difference you can feel...

I want to start a gas station that sells nothing but high octane fuels at ridiculous prices. I'll make a fortune off ignorance.

[Ken99287]

just use 87, the high octane stuff is for cars with knock sensors and forced induction applications. example - using 87 in my saab only produced 18psi boost, but high grade produces 25(knock sensor lowers boost levels), that is because higher octane makes the fuel mix harder to preignite(ignite from being pressurized), ensuring that the mix only burns when the spark plug sparks. pre-ignition/detonation is bad because it's igniting during the compression stroke-very hard on engine parts. but regular cars only need the lowest grade needed to prevent detonation. the "Porshe" badge doesn't mean it's not still just a regular ol' combustion engine. just cuz it's a porsche don't mean high grade will do miracles. now if you had a 951...

[vbaron]

Hate to lob another grenade - but what about the use of so-called "Tier 1" gas from Shell, Chevron, Phillips, etc. Has anyone gotten better gas mileage and/or has their engine run any cleaner with these gases? Here's a link that explains the concept:

http://www.toptiergas.com

[legion]

I run 92/93 in my 951...

[Mr_Wizard]

87 in the 91 S2. Used the 91/92 when I first bought it then I read a thread posted a while back, about 87 and posters said they had no problems. Have been using it for the past 7 months. Have had no knock problems or a noticable difference in gas mileage.

[ae1969]

I tuned for 94 (blended with alcohol).

IF you are stock .....just use what the owners manual says.

Pretty simple.

[mbwilser]

Stock 85/1
87 Octane / cheapest available
seems to all burn the same to me.

[Brando]

I notice a bit of gas mileage difference with 87 and 91. If I run some over-the-counter octane booster I notice a little better mileage. But then again I've got a later 944 that has a knock sensor.

[Dtchy]

I run 87 in my 86 944na. The statement I read earlier is exactly right: Use the lowest octane possible for maximum performance. You want the mixture to ignite as easy as possible, but not by itself.












Unless you drive a 944TDi, that is...

[Ken99287]

Dtchy - are you referring to my previous post?????? if so, Yay! someone agrees with me! and i'm only a new guy on this site! thank you!!!

[B. Elliott]

Running a higher octane gas that what is needed will cause excessive amounts of byproducts ie. carbon, to build up.

Since the compression is higher in mine (10.2:1) i run nothing but premium 93 (92). Coincidentally, just like the factory service manual reccomends.

http://www.sacskyranch.com/deton.htm

[legion]

I wonder if running racing gas (104) in my 951 might be a better option than 92/93 because it doesn't contain any ethanol.

[Dave L]

I use premium (what ever octane that is) in the S as that is what it calls for. In the other cars its 87 regular as thats what they call for.

through a combination of fuel addatives,, magnets and a turbonator i get 5000 mile per tank.

[AaronM]

Originally posted by Brando
I notice a bit of gas mileage difference with 87 and 91. If I run some over-the-counter octane booster I notice a little better mileage. But then again I've got a later 944 that has a knock sensor.

A bottle of over the counter octane booster will raise the octane of the 944's 21 gallon tank from 91 to 91.2. Not enough to make a difference.

Now, most over the counter octane boosters will also include a very strong detergent package and this cleaning is what yields the improved mileage.

In terms of energy content, higher octane fuel actually has slightly less energy per unit volume (not enough to be significant though). If you are seeing differences in mileage from higher octane fuels, you need to have your engine tuned up because something is mal-adjusted somewhere.

[AaronM]

Originally posted by B. Elliott
Running a higher octane gas that what is needed will cause excessive amounts of byproducts ie. carbon, to build up.

Since the compression is higher in mine (10.2:1) i run nothing but premium 93 (92). Coincidentally, just like the factory service manual reccomends.

http://www.sacskyranch.com/deton.htm

Factory recommendation is in RON, not US AKI. RON 92 = US AKI 87. US is (RON+MON)/2 and is typically equivalent to a Euro rating 5-6 points higher.

I ran 87 octane in my '89 944 NA (10.9:1 CR) and it didn't ping at all. Also did just fine on mileage.

[Ken99287]

yeah, take that, all you people wasting money on higher octanes that don't do a thing for you.