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01/08/2003 17:06:20   James   I have been discussing this with a few people who have all given different opinions. One person swears that the Saab 96 will run perfectly on unleaded. The person I bought my car from says it always ran perfectly on 4 Star LRP, whay change that? And I have also heard that if you are going to do 'big' miles at motorway speeds an unleaded conversion is a must! Please help - I'm new to Saab 96 v4 ownership and I am confused.
James  
02/08/2003 16:51:53   John   James, if you click on the 'show all posts' at the top of this discussion you will find a whole wedge of information on the petrol question on 14th May which may b helpful.  
02/08/2003 18:55:22   Alec   On top of that LRP is to be stopped soon.  
04/08/2003 07:57:05   Richard   I use an additive, either Millers Vsp or castrol valve master plus. Both these help protect the valve seats which are very soft on the Saab and increase the fuel octane rating. I have not not noticed any increase in valve clearances in numerous years of daily running.  
04/08/2003 11:24:15   Alec   Small point but if you get Valve seat recession the valve clearances will get smaller and thus the tappets would get quieter. Ensure you check the cleareances everyt 6000.
I too use Castrol valvemaster with Octane booster and have been very pleased with it.  
04/08/2003 12:41:41   Richard   good point! Its too early in the morning when I wrote this.  
04/08/2003 14:34:10   steve h   I think I said in my last post about this was that I recon that as converting to unleadded means fitting hardened valves and seats which involves taking the heads off, and since running your car on unleadded will eventually (Someone who has experience pease say how long) require you to take the heads off and have new valves and seats fitted, there is little point in doing the first till the second happens.

Views please.  
04/08/2003 14:37:03   Senor Burt   LRP is crap. It is very weak and V4's do not start very well with it, I would strongly advise against using it. I use unleaded with Wynn's lead replacement with octane booster and find that starting and power are improved.
It is not worth the risk of running on straight unleaded as these engines were not designed for it. If you drive your car like a granny then you will 'get away' with using straight unleaded for longer.
Old 4-star was a lot higher octane in the 70's and V4's run better with super unleaded or Shell Optimax(With additive and octane booster as well).
Valve seats retain a 'lead memory' for a while after stopping using leaded petrol. The lead leaves some sort of chemical coating which will protect the seats from recession. Leaded fuel is still available from some places at a high price, so it could be worth putting a tankful of proper leaded fuel in occasionally, which I know many classic car owners do.
There is also the Broquet fuel catalyst which sits in your tank and is supposed to allow you to run on unleaded. The effectiveness of this is open to some question however. Many people swear by it, but as I say, the number of 'granny' drivers out there causes me some doubt.
Ultimately, the unleaded conversion is the way to go, but is fairly expensive and you would still need to use octane booster.  
05/08/2003 14:07:47   steve h   I dont agree about the octane booster. All the octane value is, as far as I know, is the anti knock threshold of the fuel. If it doesnt knock, its fine. All an octane booster will do is make it not knock even more. If you are running a high comp engine, you might need the octane boost, but otherwise I still say, if it runs, relax and drive it.
And for the record, I had heads converted complete with a complete set of valve seals and decoke for 120 from Gosnays. As long as you have a torque wrench, you can take the heads off very easily yourself. All you then need is a lift to your local engine remanufacturer.

I do agree through that those Broquet things are a swindle. Saab driver got all bothered about them a few years ago, the result of the discussions seen to be that they had a great sales team but no effect on the engine.  
05/08/2003 16:38:37   Richard   All the octane booster does is boost the octane to that of 4 star. I would not spend my money on optimax and octane booster on a std engine, I run a 10.5:1 compession engine on normal unleaded and millers competition cvl lead replacement and she runs fine.  
07/08/2003 17:02:31   Alistair   Depending on where you live, as someone has already mentioned you can still get leaded 4*, from Thrust garages. Check out the Bayford Thrust website for locations (fairly sure there's a link from the SOC site).  


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