mixing oil

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krick3tt
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Joined: Thu Mar 16, 2006 6:48 pm
Location: Denver, CO USA

mixing oil

Post by krick3tt »

I don't see an issue with it, but I have had to add oil and did not have any more SAE 30 on hand so I put in 10w40 to top off.
Since it is winter the multi grade 10w40 may help the 30.
Anyone see any problem with my thinking?
Any man who thinks he can be happy and prosperous by letting the government take care of him:
better take a closer look at the American Indian.---Henry Ford
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Jimm391730
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Re: mixing oil

Post by Jimm391730 »

Mixing different weights is not a problem; there is a slight chance that mixing different brands might have detrimental effects. The reasoning is that oil compositions include additives for different reasons, and different brands have different additives. What if some additives from one brand have an adverse effect on additives from other brands? For example, there are additives to minimize foaming, so air bubbles are not contained within the oil. I is possible that additives from brand "B" may cause foaming when added to brand "A" oils. I have a friend who races and he is extremely picky/cautious/worried about this sort of thing.

However, generally speaking, most oils are generally compatible with most other oils, especially in non-critical applications. I don't worry about it.
Jim M.
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dadnova
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Re: mixing oil

Post by dadnova »

Don't mix synthetic oils with conventional oils.
I don't see weights of the oil an issue.
krick3tt
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Re: mixing oil

Post by krick3tt »

Thanks. I don't buy synthetic oil for any of my vehicles. That won't be an issue. I almost always use SAE 30 for the pinz year around. It was a bit low and it was a question that came up when I went to my shop and found some 10/40 for the Jeep that hadn't been used.
Any man who thinks he can be happy and prosperous by letting the government take care of him:
better take a closer look at the American Indian.---Henry Ford
Stekay
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Re: mixing oil

Post by Stekay »

Personally, I can't see any reason to use a single weight motor oil in this day and age. If I were in Denver, I would certainly use a 5W or 10W-30 oil in winter at least... (personally)
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Jim LaGuardia
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Re: mixing oil

Post by Jim LaGuardia »

The Pinz engine can drink those low weight oils, thinner oil goes down the valve guides easier and faster.
20-50 is the thinnest mix used in most air cooled applications.
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Stekay
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Re: mixing oil

Post by Stekay »

thinner oil goes down the valve guides easier and faster.
Agreed, but it can't go down the valve guides until or if it never gets there. At temperature (212 F) the 10W30 is 30 weight. It's only 10 weight at 0 degrees F.
'76 710K
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