Just had the oil changed from Shell Helix Plus 10w 40 to Millers XFS 5w 40. Engine seems nice and quiet but have noticed the oil pressure at tick over is now lower at around the 2.2/3 mark and 5.7 - 6 bar at around 30 - 35mph. It is also running at slightly lower oil temperatures. Does different oil do this please? Car is an 02 STi with 30,000 miles.

 

Yep, lower pressure at tickover due to less viscosity...the 5w/10 spec...lower temps because oil is slightly better at circulating/getting rid of the heat...nowt to worry about

 

Cheers.

So just to put my mind at rest, using 5w 40 Millers XFS oil in an 02 Sti PPP UK Impreza with normal to fairly hard driving (only short bursts) each day 7 days a week will be okay then or should I go 10w 40? Cheers

 

I used Millers XFS 5/40 in my 03 STi and saw pressures of around 30psi (2bar) at idle and 80 - 85 psi (5.4 - 5.8bar) normal running speeds with temp. at around 85c I'm now using Millers CFS 10/40 (3 ester) and see similar pressure figures, maybe a little higher when at speed.
When I changed from castrol RS 10/60 to the Millers XFS 5/40 for the winter, I thought the engine was, if anything, quieter.
In an area where there is a lot of oil discussion, Millers are an underated brand who produce a good range of types and viscosities.
JohnD

 

Cheers John. Have now read many threads on this subject and yes, there are many (understatement!) different views. Looks like I'm okay with 5/40 but will probably change like you have to CFS 10/40 at the next change.

 

Go to www.millersoils.co.uk and look out for them at some of the shows, they usually give a show discount on the day.
JohnD