When is it best to replace oil?

sawood12 · Apr 30, 2006

Oilman,
My last oil change was last November where I used Silkolene Pro 5W40 that I got from you. The cars been great since usig this oil and i've not had to top the oil up at all since then. I've not used the car extensively over the winter and there are signs of a little mayonnaise in the filler cap. I took part in my first track session yesterday - a half day session at Donington where I completed about 15 to 20 'hot' laps in total over three sessions taking care to do warm up and cool down laps. Would you advise I now replace my oil? I normally only replace the oil on a 12 monthly basis (even though the handbook says 6 months but I don't use the car extensively) as I only complete about 6-8k road miles a year and the car is garaged. During the track sessions the engine temp guage never rose above the 'normal' level but I don't know if this relates to the oil temp through the turbo.

My car is a 1987 944 turbo (220 bhp model) with 111k miles on the clock with good strong oil pressure.
The only modification is a stainless performance back box and the fittment of a dual port wastegate with an increase of boost pressure from the std 0.75 bar to 0.8 bar. The car achieved 237.5bhp on a rolling road last year.

Thanks.

macandsue · Apr 30, 2006

Hi looks like I.am the only one thats going to talk to you today.The easy way to decide if you need an oil change is subtract the cost of a gallon-- 5 litres from the cost of a knackered engine,and decide if you would like to hike out that sum.IF the answer is no then its oil change time.[8|]Nice car----have fun,do oil change tomorrow!!!

Fred Hindle · Apr 30, 2006

Change oil and filter every 3000 miles regardless, semi synthetic probably best way to go.

Fen · May 1, 2006

I've already suggested to you that you should be doing the interim oil changes in the past, Scott. It's a false economy not to - it isn't that expensive to change it and it's impossible to change it too often. I'd do it every 6 months if I were you, based on the mileage you cover.

Diver944 · May 1, 2006

I'd definitely stick to the recommended 6 monthly oil change no matter how much mileage or use the car gets. A good quality fully synthetic oil like the Silkolene will retain its properties for ages, but over time moisture seeps in to it and reduces its effectiveness. Water on bearings is not conducive to an ultra long life (by ultra long I mean 250k and over miles)