Is it safe to mix synthetic oils like Royal purple and German Castrol together and leave them in there? They of course would be the same weight of oil. Also if mixing oils, is there anything specific that you should watch out for?

 

Wouldn't hurt your car, But def. not a good idea. stick with one oil.

 

I don't think it matters that much. People at www.bobistheoilguy.com do this all the time making special 'cocktails': 2 quarts Mobil 1 with 3 quarts GTX etc. Synthetic Blends are a mixture of synthetic and dino oil conveniently packaged and those are mixtures. As long as you stick to the original viscosity range you'll be good.

 

I've never had a problem with it, nor have I heard of any

 

The different brands don't matter, it could even be synthetic and conventional, as long as the weight is the same it's not a problem.

 

I had one customer who would always bring in his own oil when I would do his oil changes, 5 qts, all different viscosity - ranging from 530 to 1540. Fucker was a little off. Went into a piece of shit Trooper.

 

Some people just shouldn't be allowed to own a car.

 

Hey, I take offence to that! How dare you, sir? How dare you?!

 

 

I would never mix conventional and synth.

 

What's the point of using synthetic if you're only going to mix em in the end.

 

I don't know what happened to the car, but to his credit, I saw it personally last at least 25k.

 

It makes absolutely no difference.
Have you never heard of synthetic blends?

 

Shouldn't it matter what group the oil falls into as well?

Would mixing a group III oil with conventional be ok, but not a group IV synthetic with conventional oil?

 

why would you want to do that? some oils have different additive packages that don't jive well together, or so I've heard.

 

Seems to me that, in a pinch, you could dump something other than the brand into your car without any ill effects. Meaning, you realize you're a quart low and can't get to a place that sells your exotic, Kazhakistan synthetic blend with rare linseed or some BS.

Then if there are some additives that may not be compatible with each other, you just do an oil change and put in your favorite. No big deal. I don't think there's a benefit to 4 quarts of .99 cent Wal-Mart and 1 quart of $1,000 Super Royal Blue Ball Supreme

 

http://www.valvoline.com/carcare/art...cid=2&scccid=2

Usage
Now, while the companies don't recommend mixing or switching back and forth, one company's synthetics are fully compatible with others and compatible with conventional oils. The source of compatibility problems was high levels of ester in the earlier synthetics. Considering the consequences, it's best to verify this compatibility, either on the company's website or with your trusted mechanic.

 

We have a car that burns a quart of oil every 2k, and we have the dealer plan for oil changes every 15K. The oil is the 15K one, but they don't cover top offs. They charge 8 dollars for the oil, and I was thinking, why pay 8 dollars for some ok oil when you can get something better for a few dollars more and just mix it it.

 

if the car is burning an quart of oil every 2K something is not right with it. i know there is some loss, but the max i have seen was on nissans and infiniti's running a VQ.

im curious, what kind or car is it and how many miles?

 

I'll post that info with some Pics when its nice and clean Its pretty normal for this car since it consumes a lot of everything...

 

BMW with big engine?

In the S6 it burns about a quart every 2-3k. I don't like Audi's oil change intervals so I do it more frequently. Motherfucker takes 12 quarts though.

 

One quart every 2K miles?!? That's crazy, my TL goes 7500 miles between changes and I haven't had to add a drop of oil. It stays at the full mark the entire time.

 

German cars burn oil, British cars leak it. When I worked for the local Audi dealer 99% of the top-offs I did for oil were on turbocharged cars, mostly the 1.8 and 2.0 turbo four banger motors. Audi considers it normal to burn through one quart between changes.

 

if your burning a quart every 2k you got rings going. tear it down, new bearings, new rings, depending on what the pistons look like maybe new. maybe new rods.