Engine oil???

[Panrixx]

If you are changing your oil might as well do you filter as well mate. 7 litres of 10/40 in mine. Stick 5 in then check the dipstick before adding the rest.

My wife and I have a 3.0L Surf each (1993 & 1995). I have just changed her oil (15/40 Semi-Synth) and filter.

My Surf also needs the oil and filter changed. The reason for my question is that when looking at what oil I had in my garage I found 5L of 10/40 Semi-Synth and 3.5L of 15/40 Semi-Synth. As I need about 6.5-7.0L of oil I wondered what harm there would be if I mixed the 10/40 and 15/40.

I also have a couple of litres of fully synth and wondered what was against using some of that.

[Apache]

I'm not sure, but there's a little nagging thought in the back of my head saying 'dont mix synthetic and mineral as bad, expensive things could happen'. Not so sure about synth / semi-synth.

As for mixing various viscosities / temperature ratings, I dont think its a biggie. I think all mixing 10/40 and 15/40 is going to do is make the oil's lower working temperature rating slightly higher.

[grabeck]

you must be able to mix mineral and synthetic oils as semi synthetic oil is a blend of both types. not much point, the mix is the lower spec of the 2 grades.

[SurfingNow]

do you all use just diesel engine oil
or the multi grade that can go in petrol and diesel??

[Apache]

I use the cheapest diesel spec I can find (got 25 litres of Chevron for £19 not so long ago) and change it frequently (every 3000 miles). Seems to be the recommendation of old hands and those in the know.

[grabeck]

diesel oil has a bit of detergent in to help keep bits clean ,but if you change the oil and filter at regular short intervals,5000km, as recommended,it doesnt really matter what you put in as long as its the correct grade.

[Taliesins]

My wife and I have a 3.0L Surf each (1993 & 1995). I have just changed her oil (15/40 Semi-Synth) and filter.

My Surf also needs the oil and filter changed. The reason for my question is that when looking at what oil I had in my garage I found 5L of 10/40 Semi-Synth and 3.5L of 15/40 Semi-Synth. As I need about 6.5-7.0L of oil I wondered what harm there would be if I mixed the 10/40 and 15/40.

I also have a couple of litres of fully synth and wondered what was against using some of that.

Yes you can mix any of the oils you mention no problem. You can mix semi and full you can even mix mineral with synthetic, not been able to is a myth.
Why do you people use semi synth or fully synthetic?
Mineral is just as good if you do the oil change as recommended and a hell of a lot cheaper.
If you do the oil change as recommended the synthetic oils are a waste of CASH.

[drunkmonkeyboy]

I just use mineral oil in mine and its runs quieter.