Mixing oil ?

[RUSSELLM]

My car's recently had the engine out & has come back with 10W/40 oil fitted.

My local indie normally puts 20W/50 in it, as its an old engine.

I've got a load of the 20W/50 stuff in stock, will it do any harm if I mix the oils, or I do I need to get the 10W/40 for topping up ?


p.s. I know FA about the mechanics of my car

[ridds]

20w/50??? I wouldn't.

[Tyre Smoke]

You can mix oils. Just make sure you have full synthetic to mix with full synthetic. I wouldn't mix full synthetic with a mineral oil (non synthetic).

20/50 in a Cerb?

I wouldn't put it in mine

a) Because I suspect it's mineral oil not synthetic

b) The viscosity is wrong for a high performance engine, 20/50 is good for your 150k miler Vectra but not an AJP V8

The above is over simplified but you did say you knoew nothing about engines.

[kojak]

Viscosity is wrong.

Stick with what they've put in.

[RUSSELLM]

It is Full synthetic, but I guess I'll stick with the 10/40 that Power have put in it.

That said, the owners handbook says 15/40 or 5/50

[Tyre Smoke]

I use 10/50 in mine - Millers XFS.

Guess you pays you money and takes your choice.

Can you use the 20/50 in something else (your daily driver??)

[RUSSELLM]

I suppose so, the car sounded better with the old stuff in though.

it's here www.76lubricants.com/index.htm

under crankcase oils, then it's "high performance fully synthetic oil"

[Tyre Smoke]

To be honest, as long as they are both synthetic you can use it to top up.

No reason not to.

[Toady1]

just dont mix minerals with synthetics! the 20/50 will quiten down the engine a bit, and raise the oil pressure a bit due to it being a bit thicker, however the 10/40 will lube the bearings easier as its thinner. I personally wouldnt say putting 20/50 in an ajp8 engine is that bad tho tbh.