Date: Thu, 09 Mar 2000 11:50:18 +0100
From: Robert Brown <>
Subject: Re: unleaded fuel - saab 1984

Hi Jan, Unfortunately no experience with that year model, but I do know that the ability of the engine to tolerate unleaded is dependent on new hardened valves and seats introduced at around 1984. I'm talking European market now. I think that the US market has had hardened valves a very long time now, due to requirements for unleaded petrol and catalytic converters back in the 1970's. The older engines need the lubrication that lead - or whatever they use nowadays - gives, otherwise the valves get damaged (caveat: see following article that disproves this statement) I have a 1983 900 GL and have been told that it's fine to use unleaded every second time I fill the car, despite the fact that I have the "old" valves. I've pasted in an answer from Saabnet that goes even further than this (see below) but at any rate you should get this info checked. regards, Robert ------8<-----8<-----------start msg from (searched on "unleaded") /bb/general/messages/36834.html, ( Feb 21 2000) Re: leaded or unleaded petrol for a turbo Re: leaded or unleaded petrol for a turbo In Reply to: leaded or unleaded petrol for a turbo posted by simon mac on February 20, 2000 at 08:57:18: When leaded regular was no longer available in the US, I specifically addressed this issue with my machinist because I have a '72 Dodge pickup which did not have hardened seats in the cast iron heads. He told me that he had been to a seminar where this issue was discussed by engineers. Their finding is that the lead creates a thin hardening on the surface of the valve seat. As long as the seats are not distrubed, switching to unleaded gas will not cause increased wear. It is only after the seats have been machined, distrubing this hardened shell, that it becomes necessary to put hardened seats in. I drove the Dodge for several years with no valve problems before putting a rebuilt engine into it.Unleaded gas has been available, and required by American cars in some markets, since 1974. GM started putting catalysts on their cars with the 1975 models. I know that California SAABs in 1978 had catalysts (I've had two); I'm not sure about '76 or '77. (My '75 99 to California specs had an air pump, but not a catalyst.) I am not aware of any particular valve problems with '72-'74 (pre-K-jet) 99's using unleaded gas. I don't know if SAAB has different part numbers for the cylinder heads used on US and European models, but as small a manufacturer as they are I can't see them using a different head in different markets just to put hardened seats in the US before they were necessary in Europe. Unless someone can supply proof to the contrary, I would say that aluminum SAAB heads with steel seat inserts should not have any problem related to the use of unleaded gas in any market. -----8<------8<----end of Saabnet post Jan van Leerdam wrote: > I recently bought a Saab 900i - 1984. Gas in the Netherlands is extremely > high so I want to pour in unleaded fuel oc-95. Does anybody has experience > with unleaded gas in saabs from this year. > > Any commend is usefuel. > > Jan van Leerdam

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