I change oil myself in my vehicles on a regular basis. I buy 10w30 oil by the case when its on sale(name brands only). Over a period of time I end up with 2 1/2qts of different brands. Is it OK to change oil again mixing brands? I grew up being told not too. True or false?
I have never had an drastic negative effects from occasionally mixing brands. I try to use that kind of oil leftovers as make up oil between oil changes, but I have also used all my leftovers in one oil change in one of my older vehicles.
My wife several years ago had a tendency to mix different oil brands and the engine just sludged up. Different manufactures use different amount of detergents and different detergents that may cause this. I do know that with Aircraft engines, reciprocating it was fround on for that reason.
Some people today say it won’t hurt yet most of the mechanics that I talk to today say don’t do it. They agree it will sludge the engine.
Yes. You can mix different brands of oil. They all must meet the minimum requirements set by the American Petroleum Institute and the Society of Automotive Engineers. But it’s probably not a good idea to mix different multi-viscocity weights.
I have done this for years; sometimes mix three different types and weights. Currently in one of our vehicles, I have some 10W-30 of one brand, some 10W-40 of another and some 15W-40 of yet another brand. The 10W-30 is some new oil that I got on sale and want to use up, I have a good supply of the 10W-40; need to use that too and the 15W-40 is diesel oil, a very good engine lubricant but not good for cat converters. The vehicle has over 200K miles and I do intend to keep it and do not plan to overhaul it soon. It burns little oil, needs none added between changes.
For winter, I’ll use some 10W-40, mostly 10W-30 and if very cold, I’ll throw in a quart of 10 weight.
Professional mechanics may say don’t do it; that is a safe answer when you don’t know better. It is also, not difficult to not mix oil brands and weights so that too makes it an easy answer.
Most people don’t even know what brand or weight is currently in their engines. If they are a quart low, they simply buy a can of any 10W-30 and dump it in. If this could cause a problem we all would have heard of it by now. Conclusion: perfectly safe to mix.
I seriously doubt that your wife’s car sludged up because of mixing various oil brands. It was likely her driving style and the oil change interval. All oils have to meet the same number of tough standards and there fore all, but a few, are FULLY COMPATIBLE.
Engines sludge up because of too much short trip and stop and go driving, and driving too far before changing the oil. If you live in a cold weather area, and drive only short trips, you need to change oil every 3000 miles, or 3 months. Your owner’s manual has more details on this. The car does not care what brand of oil you put in, except for some Volkswagesn, BMWs and a few other with special oil requirements.
Some Toyota models amd V6 GM engines has internal engine configurations that facilitated sludging. These cars were especially sensitive to sludging with any oil, if it was not changed often enough.
Don’t mix conventional (“dinosaur”) and synthetic oils.
Keep to the same weight/viscosity (e.g., 10W-30).
Stick to the service level (e.g., SF) or higher recommended for your engine.
Buy reasonably “name brand” oils you can trust.
You’ll be fine.
You can mix conventional and synthetic, thats what synthetic blends are.
You can mix different weights but not sure why you would.
You can use any API approved oils regardless of brand or price.
You can mix the service level as long as all of them meet or exceed the service level recommended for your engine.
This comes from the days when oil came from either Pennsylvania or Oklahoma/Texas. People said you could not mix these two oils. I don’t know if that was really true or not, but it all comes from the middle east now.
I really haven’t heard any negatives of mixing brands if they’re even within the same weight specifications however you shouldn’t be mixing synthetic and conventional oil that can cause some sludge to build on an engine , working on a engine at the shop now bottom end looks good but the heads ,valves, valve spring sure don’t just caked with sludge, now I wouldn’t mix regular synthetic full synthetic with conventional oil it won’t blend together right buy either Full synthetic and stay with that or a synthetic blend and stay with that the those types of oils are not compatible with conventional oil
I think you can even mix synthetic and conventional. I’ve done it with no ill effects. I think that’s what a “synthetic blend” is anyway!
My poor Buick gets the leftover oil mix and it doesn’t seem to mind.
As long as the oils have the same spec, it’s OK to mix them. This is really a question for older vehicles. Many (most?) newer cars use 0W-XX oil, and that means synthetic oil. You can’t get 0W-XX mineral oil.
On the internet I have seen several 0W20 synthetic BLENDS including 0W20 Pennzoil Gold synthetic blend with a Dexos logo on the label.
Don’t know why anyone would use it though, it’s only $3 cheaper than Pennzoil Platinum full synthetic for a 5 quart jug and ir is $3 more expensive than Syntec full synthetic, all at Walmart.
Tried it a few times and had no issues whatsoever.
There used to be urban legends about problems mixing different brands and types (synthetic and conventional) oil, and there may be an ounce of truth to those urban legends since they started long ago when oil refining standards were much lower than they are now, but you should never have an issue mixing different brands of oil.
Having said that, you’re not getting anything extra by buying brand name oil. You’re just paying for advertising and bigger profit margins. A generic or store brand oil with an identical API oil quality standard is just as good as a brand name oil.
It’s your money, and if buying brand name oils gives you peace of mind, keep doing it, but I think it’s a waste of money in most cases if you’re comparing two oils that have the same API rating and the same viscosity.