Gas in a NA 944?

[matty89]

What do you guys think ? i live in canada and its 87/89/91/94 which should you put ? i read 91 in the book but is it really what im supposed to put it ?

thnx again matt

[DizzyRoc]

I doNt want to hijack you thread. But while we are discussing octanes can we add 1 more to the list. I have a gas station near me that offers "91 oct recreational fuel w/ no ethonal added"

[smokin_944]

Matty89, (at the risk of getting flamed) I would say run regular unless your engine has been modded. Once in a while you can run a tank of 91 octane (which I do) and take it out on the highway. I know nothing about ethanol fuel so I'll just zip it on that score...

[ernie9944]

Originally Posted by matty89

What do you guys think ? i live in canada and its 87/89/91/94 which should you put ? i read 91 in the book but is it really what im supposed to put it ?

thnx again matt

Just fill her up with what we call (SUPER) here.____(SUPER SANS PLOMB)

[DizzyRoc]

i have always used 93

[962porsche]

to high of an octane is just as bad as an octane thats to low . a high octane fuel burns slower for a more compleat burn . its good when needed ! but bad when not ! a low octane fuel burns hotter and faster leaving hot deposits of unburnd fuel in the combustion chamber . run the fuel rating the the car calls for . you can change it + or - two point but try to keep it in the rang the car calls for as not to gum up the valve train . as for ethonal say clear from it when you can its crap !!! i did a 5 week study on it finishing about 4 weeks back . if you want to see some of my findings go to comscc.org forums under talk look for sunoco fuels .

[zedsn]

You only need to run 87 octane for your NA. You would just be wasting money if you put in any higher. The 91 means something else and translates to 87 octane. My owners manual went with the car that I sold so I can't give specifics but ran 87 octane with Wilks chip for years with no ill affects.

[racer]

US ratings are (RON + MON) / 2 . My fuel door says needs 87 octane (and even has the equation shown at left on the fuel door). To be honest, the cost difference, near me, is maybe 30cents.. so.. maybe $4-5/tank more for premium which isn't a big deal imho.

Ethanol is a popular additive in US fuels. Replaces the old MTBE which, suprise, was harmful to the environment. Most ethanol content fuels I've come across near me are "10%" ethanol added. I recall reading that more than 15% causes serious problems, especially in older vehicles whose fuel lines aren't made to cope with the ethanol (which degrades the older fuel lines/systems). Newer cars are built to handle the ethanol content easier.. and of course, some cars can run completely on ethanol.

[Aufgeladen944]

Even though they're rated for 87, I would run premium. It's not that much more.

Plus, I remember reading that most premium fuels don't have ethanol in them, which is a huge, huge plus for our older cars.

Anybody know where I read that? Here in NY, I think all regular gas has 10% ethanol content.

[MDH]

91 octane Shell premium WITHOUT ethanol.......
The car loves it.

[DizzyRoc]

all common gases contain up to 10% ethanol in our area. so what you guys are saying is that the 91 octane with NO ethanol added would be the best choice??

[Aufgeladen944]

Anything without ethanol is the best choice

[shinrai]

FWIW I've been running 87 grade fuel in Canada for over 10 years in my 944 with no problems.

[Porsche-O-Phile]

N/A cars run fine on 87 US. Unless you've got modified pistons for super high c/r or something, fill it up with the cheap stuff and go have fun.

That's one advantage of the n/a cars.

[smokin_944]

Originally Posted by Porsche-O-Phile

N/A cars run fine on 87 US. Unless you've got modified pistons for super high c/r or something, fill it up with the cheap stuff and go have fun.

That's one advantage of the n/a cars.

That is also my belief. I do run 91+ octane Super sans plomb if I do a road trip, I seem to get slightly better gas mileage...

[krystar]

on a car that's not built for ethanol, ethanol is "bad" it won't hurt your car much but gas mileage goes down with ethanol. all gas in midwest (maybe your part of country too) are 10% ethanol, even premium brands, even 91/93octane. you can't get away from it. just learn to live with it.

however, ethanol is VERY good if your car is built for it (no factory showroom car on the market is, not even that flexfuel crap) ethanol is equiv of 130octane race fuel. it burns cool, it burns cleanly, and it resists detonation. which means for boosted cars, you can adjust your tune (if you have tuning capability) to a much more aggressive tune. also means u can crank up the boost more w/o detonation (assuming your rods can take it)

running 91/93 in your 8v NA is just wasting money. if it makes u feel good inside that you're throwing more money away....please paypal $5 to krystar@gmail.com every time you fill up. you'll be donating to a good cause

[AaronM]

Originally Posted by krystar

however, ethanol is VERY good if your car is built for it (no factory showroom car on the market is, not even that flexfuel crap) ethanol is equiv of 130octane race fuel. it burns cool, it burns cleanly, and it resists detonation. which means for boosted cars, you can adjust your tune (if you have tuning capability) to a much more aggressive tune. also means u can crank up the boost more w/o detonation (assuming your rods can take it)

The AKI for Ethanol is about 122, not 130. The MON is 129, which is almost, but not quite, the number you quote.

I do recall seeing an article claiming that, when combined with direct cylinder injection the "effective octane rating" is 130, but that's frankly a horrible mangling of terminology that may sound good to a writer but is scientifically ludicrous. Direct cylinder injection allows an engine to use higher compressions for a given octane rating without detonation. It does not in any way change the octane rating of the fuel used. Octane rating is measured using a fixed set of protocols and you don't get to claim some "effective" rating based on wildly different protocols.

Ethanol tends to burn cooler because it has to run richer than gasoline and richer mixtures run cooler (pure ethanol forms a stoichiometric mixture at roughly 9:1, compared to 14.7:1 for gasoline); if you ran 9:1 AFR with gasoline it would burn cooler too.

Ethanol does burn more cleanly, I'll definitely give you that.

The biggest drawbacks for ethanol are that it absorbs moisture easily which limits its shelf life (gasoline is typically formulated to be stable for a year or so under normal conditions, ethanol is only good for a couple months) and the fact that ethanol is significantly more corrosive than gasoline and will cause problems with certain metals and o-rings.

Pure ethanol is a great race fuel, but for practical purposes it's not as good as gasoline for an everyday street-use fuel.

[krystar]

yea agreed. ethanol is great as special purposes fuel. but for commuting fuel, it doesn't make economic sense from a consumer point of view. ethanol contains less BTU's than gasoline by volume. so while you may be spending less at the pump per gallon, you're getting worse gas mileage so you're going to the gas station more. so from a cost per mile-driven point of view, it doesn't make sense to go E85.

but we're digressing a bit too much

[89-944NA]

Originally Posted by Porsche-O-Phile

N/A cars run fine on 87 US. Unless you've got modified pistons for super high c/r or something, fill it up with the cheap stuff and go have fun.

That's one advantage of the n/a cars.

Not all NA cars run well on 87 octane. The 89 NA has a 2.7ltr with 10.9 to 1 compression...they do not run well on 87....jump on it and it pings like crazy. The lower compression cars will run well on 87 though.

[matty89]

Originally Posted by 89-944NA

Not all NA cars run well on 87 octane. The 89 NA has a 2.7ltr with 10.9 to 1 compression...they do not run well on 87....jump on it and it pings like crazy. The lower compression cars will run well on 87 though.

so since im putting shell v power Super 91 its bad for my car if im doing short distance's ? or what? do i have to make a pool what is the cars rating in canada? its 87 or 91 ! all put what it is rated nothing less ! its NA ya but i dont want my car to get cumbusted with black smug and **** i just rebuilt the head thnx alot taht my 2cents