Porsche Enthusiasts Club Forum

Feel free to call me an idiot but I've never owned a car as old as my 1983 944 (it's the same age as me) and I'm a bit clueless regarding this. My other cars nicely say what fuel to shove in on the inside of the filler flap but on the 944 I just have a big red cap.

Is this car old enough to meant to be running on 4-star or can it be safely run on unleaded? Don't want to put a load of effort into sorting the car out and then throw the wrong fuel into it.

Cheers.

Rob, (I presume)
Yes it is the old 4 star and I am not surprised that you are confused. It does give a detailed spec in the manual. We were advised to use unleaded for our 944 with an upper cylinder lubricant, which you mix with the petrol. It seems to have worked well for over a decade.

Regards

Don't think mine has a manual, still waiting to pick the car up. Want to get one although completely unsure where to get one from.

So is it a simple case of chuck some lead replacement stuff in with the fuel or is there something else I need to do?

The fuel that's in the car at the moment (if there is any) is probably next to useless as I suspect the car's been sitting there for at least 7 years.

I asked Porsche about my 1982 944 through their website and got a phonecall back from Reading. They then checked with the engineers.

The response was that the car can run on the higher grade of unleaded without any additives or alteration.
Has been running for the last year (3000 miles) without trouble.
Be interesting to see if other people are running additives

Sorry to be a bit thick but can you define what you mean by a higher grade? Are we talking 95RON or super unleaded stuff or something completely different?

Never had a problem with normal unleaded in either of my 944's.
In the states they were fitted with catalytic converters so always were running on unleaded, there is I believe a fuel quality switch on the DME that was set depending on where the car was in the world.

Being an alloy head, and block for that matter they already have hardened valve seats. I would have thought it very unlikely that it hasn't already been tuned to run on unleaded as leaded hasn't been around for years now.

The 944 was one of the first cars made for a worldwide market so can cope with a wide variety of crap fuel from anywhere and everywhere and was designed with unleaded fuel in mind. There are a few paragraphs concerning this in the buyers guide avaiable from Porsche Specialist Hartech:

http://www.hartech.org.uk

In summary all 944's can run on unleaded, but the earlier cars may benefit from 98Ron Super as oposed to 95Ron normal

Still a few conflicting things here. Mine is an early model from 1983. I'm not sure if it has had any conversion as it hasn't moved for a long time, it was last taxed in 1999 and have no way of contacting the previous owner. It does however have a sticker from a bromley car show from 1999.

I'm still confused argh!

It will run fine on 95 ron, see pauls post above. It was built with unleded fuel in mind.

I use tesco 99ron in my 1986 turbo. The turbos have a knock sensor so can adjust the ignition timing to suit the fuel being used. And i can really feel the difference between regular and super. That's the only reason i use the expensive stuff, otherwise id just stick regular in it.

Couldn't really notice any difference between unleaded and super unleaded in my VW until going back to unleaded where it would splutter a bit at first then seemingly get used to it. Strange things cars.

I run my 1984 2.5 on ordinary unleaded and have had no problems.I recently had to have a recon cylinder head fitted due to the head being knackered(very corroded due to water leakage ) but the valves were ok so the unleaded (95 octane) was not causing any problems at 155,000 miles.I do put a squirt of Redex in every 3 tankfulls though as I believe it is good stuff and as it is a cleaning agent cant do anything but good really!

I've tended to put the 98 0r 99 RON fuel in and the car has always been happy. I used the 95 RON when a garage didn't sell the higher grade and wouldn't say I found a noticeable difference. Just sticking to what Porsche said as it is mainly a weekend car and I try not to think about the cost.

Your car shouldn't need any work to convert to run on unleaded. When I enquired, they did advise that the 944's were set to run unleaded from the beginning.

My VW Golf does feel lumpy for a while if going from 98 to 95.

The reason for using a higher RON value will be compression ratio (it's circa 10:1) & anti knock rather than valve seat recession.The overall design is very well cooled so given that our standard unleaded is good quality in the UK & europe you'll get away with it. I suspect the requirement for the higher RON value was Porsche being cautious about fuel quality world wide.

Thats very interesting as my '44 turbo came from the US originally where I do believe that the fuel is 87RON unleaded.... If this is the case then I bet mine is set for 87RON..
I always use 95RON Unleaded and the car runs fine and pulls well without complaint...!

Where is this "switch" located...? Is it on the ECU...? Could I set the fuel up to 95RON..?

Loads of questions I know....! Maybe I should leave it alone and pretend that I never seen this post