[ajengli]

The last 3 tankfull's in my 308gt4 have been 4 star (leaded) fuel which I found out is available from some filling stations - they tend to be the small privately owned ones (see http://www.fbhvc.co.uk/fillingstations.htm) It costs between £1.05 and £1.20 a litre depending on the garage. The last tank-full (Sunday) was Optimax because I didn't have time to drive to the nearest 4 star garage (about 10 miles away). My car is completely standard and performance seems to be the same whichever fuel I use.

My question is, is there a benefit from using 4* over Optimax, will I do any damage using unleaded fuel/Optimax, or shall I always try and get leaded 4*?

Andy E
308gt4
Glos.

 

[Stradale]

I think the 308GT4 is not that old to heed "leaded fuel". Those are necessary for much older cars. I had a 1989 328GTS and I used unleaded alll the time and the car runs beautifully.

 

[4kids3fish]

The switch to unleaded fuel in Aust occured in the late 70s so the chances are your GT4 will have problems on straight unleaded. I would say that as you are currently using leaded (& assuming the car has a fuel filler-tube sized big enough to allow the leaded-fuel nozzles to be inserted), then the engine is not designed to run unleaded fuel.

The problem shouldn't be the octane rating, as Optimax is 98 octane which is right up there, and so are some other premium unleaded fuels. More likely you will get progressive deterioration of the valve seats due to the lack of soluble lead to lubricate them. This can be overcome using Optimax (or similar) plus a lead-replacement additive that you will have to add to the tank every fill or so.

Can Ferrari help here? I would expect any decent service dept could advise you what is needed.

 

[Boxer]

The issue is not the octane rating but the valve seats. Here are a couple of different articles on the subject:

http://www.classiccarsmagazine.co.uk/nav?page=classiccars.specialfeatures.detail&resource=407868

http://www.vclassics.com/archive/octane.htm