Mixing oils

Submitted: Saturday, Nov 29, 2008 at 19:51

ThreadID: 63887 Views:2356 Replies:8 FollowUps:2

This Thread has been Archived

Willem

I have some 15W40 and also some 10W40 oil in the shed. Leftovers from whatever. There are 2 litres of the 15 and 1 litre of the 10

Can I mix them?

And if I can mix them will I get 12.5W40 oil or 15W40 diluted?

Cheers

Back Expand Un-Read 0 Moderator Share

Reply By: Saharaman (aka Geepeem) - Saturday, Nov 29, 2008 at 19:54

Saturday, Nov 29, 2008 at 19:54

or would it be 13.3W40........

AnswerID: 337431

Reply By: Zukscooter - Saturday, Nov 29, 2008 at 20:05

Saturday, Nov 29, 2008 at 20:05

Hey Wiilem of course you can mix them, but iwould not use them in the motor unless extreme emergency.Like to get you out of thje bush or similar.
Cheers Bob.

AnswerID: 337435

Reply By: Member - Axle - Saturday, Nov 29, 2008 at 20:05

Saturday, Nov 29, 2008 at 20:05

I Ltr of 10w40,? Change the mower oil!...lol.

Cheers Axle.

AnswerID: 337437

Follow Up By: Willem - Saturday, Nov 29, 2008 at 21:01

Saturday, Nov 29, 2008 at 21:01

Axle

Gave the mower away. No lawn here. Got rid of it when the locusts gave it a hiding in 2001. Replace the lawn with white quartz and riverstones...lol

Cheers

FollowupID: 605079

Reply By: Member - Paul W (VIC) - Saturday, Nov 29, 2008 at 20:21

Saturday, Nov 29, 2008 at 20:21

Not recommended unless the motor is clagged and uses loads of oil, i hope your not considering sticking it in the GQ?

AnswerID: 337441

Reply By: GerryP - Sunday, Nov 30, 2008 at 00:47

Sunday, Nov 30, 2008 at 00:47

Hi Willem,

Personally, I can't see a problem with it. If you were at a garage and needed a litre to top up, would you really worry all that much if it was 10 instead of 15W40 - I wouldn't. As long as they are the same (and suitable) API classification as found in your car's handbook, there should be no issue. The 10 and 15 only refer to viscosity so it will be somewhere between the two.

I will stand corrected if I'm wrong...

Cheers
Gerry

AnswerID: 337467

Follow Up By: Member - Nick (TAS) - Sunday, Nov 30, 2008 at 09:05

Sunday, Nov 30, 2008 at 09:05

The best bet is not to mix oils but...anyone who tops up their oil at servos, well they may end up with two or three differant grades of oil in their engines.
Now if it was a farm vehicle(and lets face it, they need reliable vehicles) it would get what ever oil was on hand and some farm vehicles have huge amounts of kms on them.Same goes for grease.Sometimes I think we worry to much about things.
BTW, I bet there would be a litre of old engine oil left in the sump/oil galleries of an engine when changing oil from one brand to the next.I know in our cruiser, when I had the sump off, the oil stayed clean for 500kms before going diesel black where normally it went black straight away(from oil left in the sump)

FollowupID: 605123

Reply By: Member - Serg (VIC) - Sunday, Nov 30, 2008 at 09:45

Sunday, Nov 30, 2008 at 09:45

In theory there should be no problem. But saying that I avoid mixing oils at all costs. I would say it you need to top-up half a litre for 500km to next oil change, then it should be OK. If you plan to change it, that I would say no. Use it for lawn mover or like chain lubricant in chainsaw.

Cheers
Serg

AnswerID: 337500

Reply By: Dunaruna - Sunday, Nov 30, 2008 at 10:06

Sunday, Nov 30, 2008 at 10:06

If the 2 oils are same additive package (same brand, same rating) then it's not a problem. The difference between 10 weight and 15 is miniscule in relation to domestic motors.

AnswerID: 337504