Mixing oils

[philo_beddoe]

Is it safe to mix engine oils, like using several different brands, (all 10w40) on an oil change. I received a couple cases for free of mixed name brands.

[boulky12]

Of course its safe. Changing the brand wont effect anything. It's when you start changing the weight that your motor will be effected.

[LTZ C20]

Not necessarily true. You have to read the product info for each and make sure that the "mix in" oil you are planning on using has the same properties (ingredients) as the original oil you are using.

Some additives in your original oil which are there to benefit the engine could be "watered down" by the "mix in" oil. OR, the "mix in" oil could have properties which may benefit newer engines but counter act the properties of your original oil.

Always check to make sure they have the same properties and meet the same specifications.

For example, I was recommended by the manufacturer of my short block to use Rotella T 15w-40 Heavy Duty Diesel oil. Last time I did my oil change, I didn't have enough extra Rotella to do the oil change, so I used Mobil Delvac 1300 Super 15w-40 Heavy Duty Diesel oil which is what we carry in bulk at work because it is GM's recommended oil for the Duramax diesels. The two oils meet the same specifications and contained equal property. I will continue to use the Delvac instead because it's easily accessible and I can get it for cheap. But normally I use the rule: use what is recommended, not whatever is cheap and/or on hand OR pick one oil that meets your needs and stick with it. For me that's Mobil Delvac.

You should ask Vile what his opinion is on using various oils for your engine specifically. I would use what he recommended and nothing else.

[Stewart G Griffin]

My opinion is that if you did it once or if it was a situation where you were a little low and the only thing available was a brand you normally don't use, you'll be ok.

i actually recently listened to one of Adam Carolla's podcasts which discussed specifically oil and mixing etc.:

http://tunein.com/radio/CarCast-Podcast-p345836/

i think you want the Jan 4, 2014 episode.   Only listen if you have time---it's long.

[philo_beddoe]

I did some searching around, lots of results. A lot of folks saying its perfectly fine to mix brands, viscosity, etc.

[philo_beddoe]

Just read the previous posts, hopefully VZ catches this, i'll wait to hear from him. I still have the first real oil change in there since the break in. Just reached 1k miles, the oil still looks like honey.

[Stewart G Griffin]

Further thoughts:

1). Too much oil is better than not enough or no oil.

2). The wrong weight is better than not enough or no oil.

[VileZambonie]

If you are using an oil that is incompatible with other oils for topping off etc then don't use that oil. I've made plenty of cocktails over the years and never had an issue. As far as too much oil is better than not enough, well maybe but to a very small extent.

[philo_beddoe]

Still nothing solid regarding mixing brands and weights, all in the same pot. Not to mention a little synthetic in there too.

[philo_beddoe]

Whoops, typed too soon. Thanks.

[philo_beddoe]

I have about 2 cases of mixed brands, but all 10w40.

I just hate to waste it, i'll change my oil every 1k miles just to use it up. My engine will love it. Should be fine in the warm season.

[berserk]

The only way I would mix oil is if I was flat broke and the truck was reading a half quart or more low. But I also will ONLY run Brad Penn oil's in my k10 since break in,  I don't feel like the zinc additive is as good as the oil formulated from the manufacture with it already in there.
Not a lot of facts, just a lot of preference. 

[Blazin]

I have mixed brands many many times over the years, Never had an issue.
Have mixed weights in my Jeep 4.0 before.

[Irish_Alley]

i never had a issue with mixing brands. i cant say that ive mixed weights but then again i usually add a bottle of lucas or you hear of people adding trans fluid to their oil. i would think thats like stepping up and stepping down the weight of the oil.

[philo_beddoe]

The new crate 350 engine calls for 10w30, is it ok to use 10w40 in the summer?