Unleaded in european 3.2

[tcj]

Any opinions on using unleaded 98 RON gasoline in European(non-KAT) Carrera 3.2, 1984 with 231 bhp?

I have heard different suggestions as someone claims that you should use special additives or lead substitutes to lubricate your valves and at least using them keeps valve adjustments better in their specs. Some others say no big difference unleaded or not as it is 98 octane.

Any comments and advices appriciated.

Thanks/TcJ

[ttweed]

You do not need leaded gas in a Euro Carrera. There are plenty of them here in the US running on crappy 91 octane unleaded gas and doing fine, despite the higher compression ratio.

The lead does not "lubricate" the valves, anyway, it "cushions" them as they land on the seat. This is considered to be unnecessary with modern hardened valve seats.

TT

[Bill Verburg]

Euro 3.2s run fine on US 93, 94 is preferred when the temp gets into the high 90&degF range. All 911 since at least 72 are designed to run on unleaded. While leaded does aid octane it makes a mess of oher intrnal components, we are all better off w/o it.

[tcj]

Thanks Tom and Bill,

It seems that there are various opinions on leaded/unleaded at least here in Finland/Europe where I and my P-car happily live.

However, I have never heard that somebody actually has broken his engine with unleaded. On the other hand almost every gas station sell their own substitute for lead and easily afraid people with terrible engine rebuild if you do not use them.

Low octane is perhaps easier because I think you can hear knocking in some form or other if it runs too low.

Anyway the previous owner ran 50 kmiles without substitutes and without problems so perhaps I will continue that.

/Tommy

[Paco Anton]

My '83 SC with 10.5:1 compression uses European unleaded 98 RON gas. Your car, being newer shold have no problems.

I own a euro 1984 Carrera 3,2. When Stef Scheepers still attended this board I had him ask someone in the engine department at Porsche AG if my car needed lead substitute.

Answer: Yes. Only 1985 3,2 models and newer can run without it.


Later I wrote directly to the Porsche AG service department. Same answer. 84 models need lead substitute, 85s and newer don't.


I run my car on lead free 98 octane and add Castrol lead replacement in the fuel. The previous owner did the same because Porsche Zentrum Braunschweig recommended it.

[Bill Verburg]

Lead served 2 functions

• octane enhancement
• cushining of exhaust valve seats

Since at least '72 all 911 engines have had the hardened seats which negated the need for function 2

In '84 when the Carreras first came out, there was a poor supply of 98 RON unleaded fuel, hence at that time, lead was prefered in the higher compression ROW 3.2 engines. In '85 the lower compression cat equipped engine was an option in Germany and used leaded alongside it's higher compression brother. Since then the abundant worldwide supply of 98RON unleaded has obviated the need for lead(function2).

Over here in N.A. 98RON(european high test gas) is the same as 93AKI/CLC(pump posting#). High compression 231hp Carreras run fine on 93AKI/CLC.

Your sparkplugs and oil will thankyou for using unleaded.