Originally Posted by FASTdan
oilman, as always a very informative post. a quick question for you....
In an engine such as a Fiesta RST (low mileage rebuild) running castrol magnatec 10-40 currently (but may change to what you recommend) what sort of pressure drop do you expect as a result of increased temps? ie standard CVH pressure specs @ 80degs C are:
14psi @ 900rpm
41psi @ 2000rpm
63psi peak
my car tends to run around 90degs but i only see 35psi, and a peak of just under 50. idle is always fine at 14-16psi. these are taken on a reasonable quality capillary mocal oil pressure/temperature gauge.
I am trying to decide if i have anything to worry about or if it is simply a degradation due to temp.
cheeers
If you switched to something like Silkolene PRO S 5w-40 I would not expect any change in oil pressure to a 10w-40 as they are both sae 40's but the difference would be that the Silkolene would maintain these pressures for a much longer period of time being a proper synthetic.
You would get more pressure from an sae 50 but depending on quality the time period for this pressure would vary.
Cheers
Simon