Discussion
hi everybody
Im a bit confused as to what fuel would best suit a 22 year old 944.
not being sure wether there was a factory mod in the ignition and/or timing with the advent of unleaded fuel, it says on the inside of the filler cap "min 98 ron" but 98 ron in 1984 could have ment anything from 94 to 99 coming out of the pump.
any information on the subject would be appreciated.
thank you
Im a bit confused as to what fuel would best suit a 22 year old 944.
not being sure wether there was a factory mod in the ignition and/or timing with the advent of unleaded fuel, it says on the inside of the filler cap "min 98 ron" but 98 ron in 1984 could have ment anything from 94 to 99 coming out of the pump.
any information on the subject would be appreciated.
thank you
Edited by b.johnson on Wednesday 12th July 14:07
The curved dashboard 944 (Autumn 1985 onwards) has an ECU that can be switched for poor fuels and has several different positions with changes to ignition curves and injector pulse times (with little affect on performance) - but the square dash 944 (pre 1986) does not - so it is best to use Optimax or similar.
Having said that the engine management systems automatically adjust for load conditions and the older 944 does run very rich on acceleration (and compressions are generally dropping with age and bore wear) and so unless you are driving it flat out or on a track and you rarely use full throttle for prolonged periods - then you should be OK in an emergency using 95 grade.
The worst case seems to be on a straight flat road at about 50mph (when the engine management system runs the car at the weakest setting for ecconomy). Cars with knock sensors will often shut down briefly in this mode when run on low octane fuel. Typically the 944S was prone and we have had similar problems with a 944 turbo that went to Ireland when poor fuel was all that was available.
Baz Hartech
Having said that the engine management systems automatically adjust for load conditions and the older 944 does run very rich on acceleration (and compressions are generally dropping with age and bore wear) and so unless you are driving it flat out or on a track and you rarely use full throttle for prolonged periods - then you should be OK in an emergency using 95 grade.
The worst case seems to be on a straight flat road at about 50mph (when the engine management system runs the car at the weakest setting for ecconomy). Cars with knock sensors will often shut down briefly in this mode when run on low octane fuel. Typically the 944S was prone and we have had similar problems with a 944 turbo that went to Ireland when poor fuel was all that was available.
Baz Hartech
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