Petrol

[chashall]

Hi, recently bought a 1980 SC, can anybody advise if I can use unleaded or do I need an additive? Thanks Chas Hall

 

[chris.hevey]

I have an 81 SC which has the same three litre engine. Good news is no additives required, slightly bad news is it has to be higher octane, e.g. Shell V-Power

 

[dij999]

I always used an additive in my '81 yr model SC - was suggested that damage was possible - especially to valve seats - without an additive. Fitting 'hardened' valve seats was suggested but additive was cheap enough for the number of miles I did in her.

The higher octane requirement 204bhp engine started with the '81 model though, before that was the lower octane requiring 188 bhp engine. But to complicate matters, Porsche started selling the '81 model spec in late 1980 (mine was one of those) so if yours was registered in 1980 you need your engine number to tell you which - the 204bhp engine started with 631xxxxx and 188 bhp engine started with 630xxxxx.

The chassis numbers also changed format for the '81 models - began with WP......., before that began with 91...... but engine number better for you of course in case your SC had an engine change.

 

[T911UK]

VIN changed in 1980 to letters showing year, A = 1980 B = 1981 etc so it should be easy to see what M/Y you have

 

[ian harvey]

If I remember correctly the other advantage of super unleaded is that it contains the least bio-ethanol (less than 5%) which plays havoc with the older fuel injection systems. I think the BP stuff has none at all and I prefer this and/or V-max.

 

[Old and Slow]

Although not essential, I put Millers VSPe as recommended by the FBHVC, in with the Shell V-Power or BP fuel; better to err on the side of caution?

 

[chashall]

Many thanks all.

I do have the later engine and use premium fuel already.

Sounds like an additive will do no harm and may help.

As mileage will be low I'll follow that advice

Thanks again.

 

[chrishak]

SC's have hardened valve seats, additives are not necessary. However, a low bioethanol content is essential (e.g. Shell V-Power @ 5% max or BP Ultimate with zero ethanol) as higher percentages can cause havoc with the fuel lines on an air-cooled 911.
By the way, this is a repeat of a thread which was running just a few weeks ago - loads of info on there.