mixing oils

[vodkakid]

Now i know you shouldnt mix your oils but is it possible to mix grades. My problem is ive got to top up my oil urgently but i cant off hand remember the grade of mobil 1 i have in the car and i cant check without a long drive, so is it ok to mix the grades
i know this is a stupid question but if you dont ask you dont know
cheers

[zippy500]

In theory as long as both oils are of the same type, i.e. synthetic etc. you can mix them. mixing different grades depends on how different the 2 are and how much you need to add. Mobil 1 is I think 0W 40 grade?. Most grades will be around this mark and as long as they are fully synthetic can be mixed without too much trouble. This is my personal view and others are bound to differ. I would top if if necessary with a different grade and would not worry too much. Particularly as many owners run on the higher viscosity Mobil motorsport grade with no problems. I wouldnt add a thinner oil though as your pressure may drop a bit low if it gets a bit hot under the collar.

[vodkakid]

i was gona get mobil 1 again but i couldnt remember the thickness

[Painey]

I had a similar problem to this recently. I bought my griff in february and the guy who I bought it from said that TVR Power serviced it last and put a special grade oil in it, this grade being 5w 50. When my oil level was becoming low I tried to locate some of the same grade oil but without much success so I phoned TVR Power up and asked if it was possible to mix the grades and they said I shouldn't under any circumstances do this and that if I really couldn't find the oil I needed then I should go for a complete oil change instead.

I spoke to a guy there called Dom who was very helpful so what he said might be worth listening to, even though it will unfortunately set you back a few quid. Hope everything gets sorted!

Cheers - Chris.

[incorrigible]

vodkakid said: i was gona get mobil 1 again but i couldnt remember the thickness

Viscosity dear chap

Don't mix synthetic and non-synthetic, that's not good

You should be OK mixing synthetics though,

BTW I think the 0/40 is too thin, but others will dissagree, I use Millers 10/40 fully synth

[and]

From memory I'm sure Joospeed commented on this a while ago saying that a significant proportion of the Oil capacity is in the pipework / elsewhere (6 litres rings a bell) when you do a "full" change. Therefore unless you use the same brew from new your oil is mixed by default.

[the dodger]

When I checked mine recently I discovered the level almost off the dipstick!

Had been told it had been filled with m/sport 15W-50 at service but topped up with 5W-50 which is available only in France/continent I believe. Now it's all I reckon I must have 10W-50 in my sump - should be OK.