Page Index Toggle Pages: [1] 2  Send TopicPrint
 10 Fuel type/grade for porsche 944? (Read 5783 times)
shawn
New Member
*
Offline


944

Posts: 2
Joined: Dec 3rd, 2014
Fuel type/grade for porsche 944?
Dec 3rd, 2014 at 7:07am
Print Post  
Does anyone know if a 1983 porsche 944 uses regular (87 octane) or premium (93 or higher octane)?
  
Back to top
 
IP Logged
 
Zündfolge
Experienced Member
*****
Offline


'83 RoW

Posts: 1454
Joined: Mar 22nd, 2013
Re: Fuel type/grade for porsche 944?
Reply #1 - Dec 3rd, 2014 at 7:19am
Print Post  
Welcome to the forum! Shoot your questions, and pay with pictures Tongue

See if you can find an owner's manual online, there you'll find that kind of information. Old school manual expecting old school users, they describe how to change fluids etc. - unthinkable today!

Note that US cars are rated differently than rest-of-the-world (RoW) cars. Here's the US manual:

"Fuel Recommendation
Your Porsche is equipped with a catalytic converter and must use UNLEADED FUEL ONLY.

944: Minimum octane rating is 91 RON (87 CLC or AKI rating on US fuel pumps).

944 S / 944 Turbo: Minimum octane rating is 95 RON (90 CLC or AKI rating on US fuel pumps).

Federal law prohibits use of leaded fuel in this vehicle.
[...]"

Followed by a definition/conversion of different "octane" numbers.

RoW cars have a higher compression and are supposed to run on 98 "octane" - note that the definition of "octane" may differ, and what "regular" means, too.
  

Wheelwell ate my workshop log.
Back to top
 
IP Logged
 
marty944
Junior Member
**
Offline


an early survivor #1053

Posts: 50
Joined: Oct 5th, 2013
Gender: Male
Re: Fuel type/grade for porsche 944?
Reply #2 - Dec 3rd, 2014 at 1:57pm
Print Post  
Now that octane ratings are posted, here is an additional comment: avoid ethanol. avoid it in your lawnmower as well as your classic cars. the brand is not as important as the octane and the purity. I have one local provider that has a mid grade that is sold for about 5% more than the ethanol low price leader. I get an additional 10% range from this fuel over ethanol, so the savings is direct. this does not count the savings to the indirect engine maintenance. it is not necessary to pay for premium.
I would also recommend at least an annual fuel additive course. I prefer Lucas, some prefer Chevron, some like Sea Foam,  but whichever brand you choose be sure to keep that fuel line clean. it is much easier to keep the injectors clean than to repair.
I also suggest an occasional treatment, if not continual, of Marvel Mystery Oil in the fuel. I have found it at wal mart in a large jug.
  

Marty 944&&'83 944 n/a Platinum Metallic option 456&'70 914 orange -sold
Back to top
 
IP Logged
 
Greg_P
Junior Member
**
Offline


I love Forum 1G - SP1!

Posts: 61
Location: Wash.
Joined: Dec 7th, 2011
Gender: Male
Re: Fuel type/grade for porsche 944?
Reply #3 - Dec 4th, 2014 at 8:51pm
Print Post  
Good information above.

In my '84 NA I always use unleaded regular.  Runs great.

Greg
  
Back to top
 
IP Logged
 
pfarah77
Experienced Member
*****
Offline


84 NA, It will be brand
new when I'm done!

Posts: 1191
Location: MA
Joined: Jan 9th, 2013
Gender: Male
Re: Fuel type/grade for porsche 944?
Reply #4 - Dec 4th, 2014 at 11:11pm
Print Post  
I typically use Shell, Mobile 93, or Sunoco 94 octane whenever possible.
  

Patrick
Back to top
 
IP Logged
 
Dave W
Experienced Member
*****
Offline


Just your basic car guy.

Posts: 5696
Location: CA
Joined: Jan 14th, 2009
Gender: Male
Re: Fuel type/grade for porsche 944?
Reply #5 - Dec 5th, 2014 at 11:00pm
Print Post  
pfarah77 wrote on Dec 4th, 2014 at 11:11pm:
I typically use Shell, Mobile 93, or Sunoco 94 octane whenever possible.


You're just wasting money unless you have a turbo.  The NA is spec'ed to use 87 octane (US rating).
  

Dave - black 84 no longer exists. Sad 83 self destructed. All better now. Smiley
... Let's go hit some twisty roads! ...
Back to top
 
IP Logged
 
Joe Sharp
Experienced Member
*****
Offline


Here's a toast to Joe's
944

Posts: 3247
Location: Easton, Maryland
Joined: Jan 9th, 2013
Re: Fuel type/grade for porsche 944?
Reply #6 - Dec 6th, 2014 at 2:22am
Print Post  
I also use 93, but only because the station in my town that does not have ethanol ,only has ethanol free gas in 93 octane.

when gassing up somewhere else I only get the 89.
  

1989 S2 (clone) Guards Red
Back to top
 
IP Logged
 
pfarah77
Experienced Member
*****
Offline


84 NA, It will be brand
new when I'm done!

Posts: 1191
Location: MA
Joined: Jan 9th, 2013
Gender: Male
Re: Fuel type/grade for porsche 944?
Reply #7 - Dec 6th, 2014 at 3:10am
Print Post  
Dave,

I found the car actually is more responsive and gets better gas mileage.
  

Patrick
Back to top
 
IP Logged
 
porschecidal_maniac
Experienced Member
*****
Offline


Maniac Racing - You're
never too old to play
cars.

Posts: 6133
Location: New Jersey
Joined: Nov 23rd, 2010
Gender: Male
Re: Fuel type/grade for porsche 944?
Reply #8 - Dec 6th, 2014 at 2:13pm
Print Post  
pfarah77 wrote on Dec 6th, 2014 at 3:10am:
Dave,

I found the car actually is more responsive and gets better gas mileage.



Patrick, please don't take this the wrong way, but this is in your head. If you're getting better mileage with 93, then you're driving differently. NA 944 cars have, at most, 10.6:1 compression, and I'm certain that yours is under 10:1. You cannot burn the octane in 93 fuel. Therefore, each gallon of gas you put in your car has less gas and more additive. Since our cars literally waste the octane, you cannot get more mileage from less fuel, unless as I said before, you drive it differently.

I have tried every variety, brand and octane rating of gas in our cars, Turbo and NA. The best blends for NA cars are non-ethanol 87 or 89 fuels with ethanol. The extra detergents in the 89 and the octane have some isopropyl that absorbs the ethanol. There is much less unburned fuel. Turbos need to run premium, but not for the octane, instead it's to prevent knock and resultant detonation again caused by ethanol. at 1 bar, the cars only have 8:1 - 8.5:1 compression, and boosting, the equivalent is about 12:1. They can burn the octane, but it's more important that there's no water.

I will share a secret right now - If you guys want to try something out of the box and see some real results, go to a marine or auto store and get a bottle of Stabil Marine Ethanol treatment. Add it to 89 grade fuel at it's recommended dilution. Wipe the orange sweat from the inside of your oil filler cap. In 1-2 tanks of gas, you will no longer have moisture in your fuel or oil and your car will run like it's on steroids. You can do this all the time. It costs less than the differential between regular and premium and is way more beneficial for your car. Don't blab this out, it's my trick and I count on the better performance on track days.
  

Jason Gonzalez
944GT & 951GTS
R7 Racing & Restoration & ManiacRacing.net
exclusive.multibriefs.com/author/jason-gonzalez
Back to top
WWW  
IP Logged
 
pfarah77
Experienced Member
*****
Offline


84 NA, It will be brand
new when I'm done!

Posts: 1191
Location: MA
Joined: Jan 9th, 2013
Gender: Male
Re: Fuel type/grade for porsche 944?
Reply #9 - Dec 6th, 2014 at 11:52pm
Print Post  
Jason,

Maybe you're right, I do like spending more on fuel Grin.

Perhaps I had a couple of bad (contaminated) fill-ups in the past which jaded me.
  

Patrick
Back to top
 
IP Logged
 
Chewbacca 911 Burritos
Experienced Member
*****
Offline


Formerly Corsepervita
Now with more flavor!

Posts: 5513
Location: Oregon
Joined: Apr 14th, 2009
Gender: Male
Re: Fuel type/grade for porsche 944?
Reply #10 - Dec 9th, 2014 at 4:35pm
Print Post  
porschecidal_maniac wrote on Dec 6th, 2014 at 2:13pm:
Patrick, please don't take this the wrong way, but this is in your head. If you're getting better mileage with 93, then you're driving differently. NA 944 cars have, at most, 10.6:1 compression, and I'm certain that yours is under 10:1. You cannot burn the octane in 93 fuel. Therefore, each gallon of gas you put in your car has less gas and more additive. Since our cars literally waste the octane, you cannot get more mileage from less fuel, unless as I said before, you drive it differently.

I have tried every variety, brand and octane rating of gas in our cars, Turbo and NA. The best blends for NA cars are non-ethanol 87 or 89 fuels with ethanol. The extra detergents in the 89 and the octane have some isopropyl that absorbs the ethanol. There is much less unburned fuel. Turbos need to run premium, but not for the octane, instead it's to prevent knock and resultant detonation again caused by ethanol. at 1 bar, the cars only have 8:1 - 8.5:1 compression, and boosting, the equivalent is about 12:1. They can burn the octane, but it's more important that there's no water.

I will share a secret right now - If you guys want to try something out of the box and see some real results, go to a marine or auto store and get a bottle of Stabil Marine Ethanol treatment. Add it to 89 grade fuel at it's recommended dilution. Wipe the orange sweat from the inside of your oil filler cap. In 1-2 tanks of gas, you will no longer have moisture in your fuel or oil and your car will run like it's on steroids. You can do this all the time. It costs less than the differential between regular and premium and is way more beneficial for your car. Don't blab this out, it's my trick and I count on the better performance on track days.


Yep, Jason nailed it.  Octane is the resistance to igniting from compression.  However, this also means harder to burn.  High compression motors use high octane fuel, and can burn it all.  If you're using too high of an octane on a lower compression motor you can't burn all the fuel.  The result is less burn, wasted fuel, wasted power.  Agreed 100% with Jason here, it would because you are driving different (placebo effect), not because of the gasoline. 

Some years go some of the guys on a motorcycle community had this discussion and finally dyno'd the results.  Lower compression motors with high octane gas made less power, period.
  

- '99 Ducati 900SS
- '87 Lamborghini Jalpa
- '77 Porsche 924 (trackday project)
- '79 Porsche 924
- '80 Porsche 931 (Daily)
Back to top
 
IP Logged
 
pfarah77
Experienced Member
*****
Offline


84 NA, It will be brand
new when I'm done!

Posts: 1191
Location: MA
Joined: Jan 9th, 2013
Gender: Male
Re: Fuel type/grade for porsche 944?
Reply #11 - Dec 10th, 2014 at 2:32am
Print Post  
Thanks for the explanation guys.
  

Patrick
Back to top
 
IP Logged
 
vintageant
New Member
*
Offline


944

Posts: 5
Location: Miami, FL
Joined: Sep 1st, 2018
Gender: Male
Re: Fuel type/grade for porsche 944?
Reply #12 - Mar 2nd, 2019 at 6:13pm
Print Post  
OK, old thread, but just found.

Who is using Rec 90 gas in their 944?
  
Back to top
 
IP Logged
 
Springgt
Junior Member
**
Offline


I love Forum 1G - SP1!

Posts: 77
Location: Houston
Joined: May 21st, 2008
Re: Fuel type/grade for porsche 944?
Reply #13 - Mar 3rd, 2019 at 6:17am
Print Post  
I've used regular 87 octane fuel in my '84 since it was new with zero problems.  That is what the owners manual specified.  It runs great on it.  Every 5-6 tanks, I also add a bottle of Chevron Techron fuel injector cleaner.

Both regular and premium contain pretty much the same number of BTU's per gallon which is why they both get pretty much the same mileage.  If your engine doesn't need the additional anti-knock capability of premium fuel, don't buy it, as it is just a waste of money.




  

Original owner 1984 944 Guards Red
Just back on the road after a 7-8 year storage.  Yea!
Back to top
YIM  
IP Logged
 
SactoJohn
Experienced Member
*****
Offline



Posts: 886
Joined: Nov 24th, 2013
Gender: Male
Re: Fuel type/grade for porsche 944?
Reply #14 - Mar 19th, 2019 at 4:42am
Print Post  
91 Ron = 87 US. Unless you change compression higher octane isn't going to run any better. If you have a smog test in your state it will usually have a higher reading with higher octane in an engine not designed for it so if you are on the borderline, you might actually fail the test thinking you would buy "the good stuff" for the smog test. Ideally you don't want the fuel burning too fast or too slow so buy the fuel the engine was designed for. Unfortunately, in CA we are stuck with 10% ethanol in our gas unless we buy racing fuel for $$$. It runs fine in my 944, but it evaporates after sitting a few days in my Edelbrock on the truck and it vaporized in the 280z I used to have whenever I parked somewhere longer than 5 minutes.
  
Back to top
 
IP Logged
 
Page Index Toggle Pages: [1] 2 
Send TopicPrint
Bookmarks: del.icio.us Digg Facebook Google Google+ Linked in reddit StumbleUpon Twitter Yahoo
 
  « Board Index ‹ Board  ^Top