When doing an oil change, is it SAFE to do a half-n-half mix of 10W-60 & 5W-30 weight - The Unofficial BMW M5 Messageboard (m5board.com)

FAST 5 · 9th March 2004, 10:45

Hi Guys,
For my residential region, I feel as though the 10W-60 is a bit too thick but I also feel that the 5W-30 is bit on the thin side, especially for aggressive driving and hot summer days. So I was wondering if it would be okay/safe to combine the two weighs when doing an oil change, adding 4 quarts of the one weight and another 4 quarts of the other weight motor oil. Will this cause any harm or damage to the engine or any other parts/aspect of the car???
Thank you.
Robert

MIB · 9th March 2004, 11:14

Quote:

Originally Posted by FAST 5

Hi Guys,
For my residential region, I feel as though the 10W-60 is a bit too thick but I also feel that the 5W-30 is bit on the thin side, especially for aggressive driving and hot summer days. So I was wondering if it would be okay/safe to combine the two weighs when doing an oil change, adding 4 quarts of the one weight and another 4 quarts of the other weight motor oil. Will this cause any harm or damage to the engine or any other parts/aspect of the car???
Thank you.
Robert

Hey Robert,

Do not even think about it buddy. That is a huge

Never mix Oils, EVER.

The very least thing that will happen is, you will start to burn more Oil.

Some Oils do not play nice together. I don't even mix brands of Oil of the same viscosity.

Its ALL or Nothing, when it comes to Oil.

Would you mix Tomato Sauce (Ketchup) with Chochlate topping (Brown cholate poured on ice-cream)

Both are good by themselves. Would be horrible nothing when mixed.

I'd say there would definitly be a warranty issue mixing Oils as well.

They both do a differnt job. Mixing together will not make them do a job in between, rather it will make both of them in-effective at the job it was designed to do.

I guess it is like combining shampoo and conditioner. Shampoo is meant to open up the hair and clean it. Conditioner closes it back up and moistens.

So how do you open and clean the same time as seal and moisten. You can't 100% effectively.

You can't have your cake and eat it on this one robert. Otherwise there would be no need for Oil R&D.

We could just mix up our own custom brew.

Lscman · 9th March 2004, 12:19

A mad scientist approach is probably unwise, but you're OK mixing oils of the same type & brand. I am not sure what products you're mixing. For example, I would not mix Castrol TWS 10W-60 with the non-TWS 10W-30 BMW lubricant because the additive package is probably quite different.

Mixing different viscosities of the same lubricant ensures additives are similar. That said, there's seldom a need to intentionally mix oils when there's so many viscosities available. I would select a product of the desired viscosity. If you want 5W-40 or 10W-40, why not buy it? Mobil strongly encourages racers to mix their 10W-30 and 15W-50 to achieve desired viscosity index.

iMac · 9th March 2004, 14:24

Do NOT mix oils , specially syntetic !!!!!

Mineral oils can be mixed.
iMac

Terk · 9th March 2004, 15:23

Quote:

Originally Posted by MIB

Would you mix Tomato Sauce (Ketchup) with Chochlate topping (Brown cholate poured on ice-cream)

Interesting comparison Mark. Somehow I'm surprised that Vegamite did not get the call on this post,

but anyway excellent response to Roberts question.

Regards,

T-Man.

AJ · 9th March 2004, 16:17

actually, oil mixing is a very common hot-rodding practice. you can pretty much mix anything to get what you want in terms of viscosity and thermal stability. you can mix different viscosity oils, you can mix synthetic and mineral. and yes- if you mix 10-60 and 10-30 you will get 10-45 - it does work like that.

on another related note, there are no oil-specific engines. every engine runs satisfactory on any type of oil with the correct viscosity. the oil-caps with imprinted brand of oil mean that that particular vendor won that particular contract to supply the oil for the engine testing. same is true for "factory" oil filters. your "factory" oil filter is manufactured by whichever manufacturer happened to offer the lowest price at the point of negotiation of the contract.

but why bother mixing oils? unless you know what you are doing, you risk to run a too-thin or too-thick oil and cause more trouble that the few bucks you save are worth.

oh, there are also no bike-specific oils. the bike community runs largely mobil one and is very happy with the long and short-term results

ofcourse this is my opinion and mine only. but at least i am telling it as i see it out there

alex

mfettara · 9th March 2004, 19:06

Quote:

Originally Posted by FAST 5

Hi Guys,
For my residential region, I feel as though the 10W-60 is a bit too thick but I also feel that the 5W-30 is bit on the thin side, especially for aggressive driving and hot summer days. the engine or any other parts/aspect of the car???
Thank you.
Robert

Hello,

The S62 engine is apparently designed for 10w-60 oil and using another will yield higher oil consumption. I believe there are several threads on the subject.

Hope that helps

cheers

apt333 · 9th March 2004, 21:26

I occasionaly mix an extra virgin olive oil with an infused 2nd pressing of a flavored oil. Delicious on salad.
But I would never mix motor oils. It's not the same as combining 1/2 tank 100 octane with 1/2 tank 91 octane to get a 95.
Different properties, different results.

Silverstreak · 10th March 2004, 01:00

The basic question is "Why?" What advantage could you possibly obtain?

MIB · 10th March 2004, 02:33

Quote:

Originally Posted by AJ

actually, oil mixing is a very common hot-rodding practice. you can pretty much mix anything to get what you want in terms of viscosity and thermal stability. you can mix different viscosity oils, you can mix synthetic and mineral. and yes- if you mix 10-60 and 10-30 you will get 10-45 - it does work like that.

alex

We are not talking toy Hot Rods. A sure way to make your engine BURN lots of Oil is mix Synthetic and Mineral.
I have even spoken with mechanics that say, once you start with one, stick with it for the life of the motor. Don't swap to the other.

It may be fine for a weekend Hot Rod, as Oil consumption is not really noticed due to low miles, but on a daily driver, it will become evident really quickly.

I cannot see any benefit at all. I only see down sides to doing this.

Quote:

I occasionaly mix an extra virgin olive oil with an infused 2nd pressing of a flavored oil. Delicious on salad.

Now this I can condone.

Hey T-Man,

People here have Vegemite and Cheese, YUK. and Tomato and Vegemite Double YUK. The Vegemite is a Stand alone product, on Buttered bread or Toast. Good on toasted muffins and crumpets as well.

ChuckC is meeting with some Aussie friends of Mine in Texas for the Big Mannafest. I have sent along a big jar of Australia's Finest.

I'm sure he will report on it, when he returns.