Yes. Try not to mix different weights or synthetic and non synthetic. Just make sure the oil meets the API service rating for your vehicle.
1-7-14 update.. I have read for a hundred hours on this topic. Most experts
write no problem mixing weights or brands. Most gasoline's differ yet most
folks do not think twice about changing gasoline brands without a bone dry fuel tank.
Motor oils come in different grades. The higher the grade, the better quality the motor oil. Some high end vehicles require better quality motor oil to run at their utmost. Otherwise, any grade will do.
All major brands of motor oil are manufactured to the same standards. To pick a best if impossible. But saying that Synthetic is superior to conventional oil.
Yes, motor oil is a compound, but actually it is a mixture of a number of compounds. There are a lot of different hydrocarbon molecules that make up motor oil. Some are the "mixed bag" of hydrocarbons that are the out-take from the cracker (the fractional distillation column or tower) during refining, and some others are the ones that are "added into" the mix by the petrochemist who is formulating the motor oil.
Nothing if they were approved oils. You can mix 10w30 with 5w20 etc. Not a good idea but you can do it. You can mix brands with no problem.
# ammonia mixed with honey # carrot juice
Yes you can mix different brands but I recommend you do not mix different weights. You can even mix synthetic oil with conventional oil. But as the weight of the oil is critical, do not ever mix one weight of oil with another, no matter if it is synthetic or conventional oil.
All major brands of oil are good. The most important thing is to use the correct weight of oil and a quality oil filter. Purolator, Bosch, Wix, AC/Delco, & Motorcraft are all quality brands.
when motor oil is heated it viscotity rises and becomes thicker
2 Cycle oil does not "burn" so that it leave behind a oil film when the gas burns off. you may see the words "ash-less" on some brands of 2 cycle oil. 4 cycle oil will burn and turn sticky, gumming up your engine.
No harm will come from topping off the oil level with a different brand. All oil manufacturers use a similar oil additive package. I would stick to one quality brand of oil. More important is using the designate API grade and viscosity.
Different oil companies at different times and different regions of the country.
Answer Since oil floats on top of Anti Freeze, all you will have is a mess.