mixing synthetic oils

[russ123]

Can you mix different brands of snythetic oils?? [ always have some left from last oil change]

[Wells]

Can you mix different brands of snythetic oils?? [ always have some left from last oil change]

While I try not to, many other people say its okay.
Really if you think about it, not all the oil gets drained during an oil change anyways.
So every time you switch oils your mixing it already.
In my vehicles its easy, they always get the same brand and type of oil, usually from a pneumatic pump system on a barrel.
But i know most people are not car buffs, and just pour in whatever they get at the gas station, and it never seems to really cause a problem.
So my answer would be, sure why not.

[Avro Arrow]

There's nothing wrong with it. The formulations that are used in names like Castrol, Valvoline, Havoline, Quaker-State, Pennzoil, etc. are usually not even developed by them. The lubricant formulations are developed by petroleum research companies (the names of which escape me at the moment) and are licenced to the "producers" for a fee. They all end up using the exact same additive packages because to do otherwise would be too risky. To constantly be trying to improve their product left to their own devices would be prohibitively expensive and so they don't. This is why they all release their oils with the newest API rating (SL, SM, etc.) at the same time. If they actually developed their oils separately, one would have the new rating long before the others. Of course this doesn't happen. Motor oil is 100% marketing when it comes to choosing one over the other. This is why you'll never hear one oil commercial say that they are better than the rest. All you get are apples-to-oranges comparisons like Castrol Syntec vs. conventional motor oil. Haven't you ever wondered why Castrol never compared their Syntec to Mobil 1, Quaker-State SynPower or Pennzoil Platinum? Another little slogan that is oh-so-telling is "There's nothing rated higher than Valvoline". Technically, this is 100% accurate. There really is nothing rated higher than Valvoline. What they don't tell you is that there's nothing rated lower than Valvoline either because they all have the same formulation and meet the same specs. It's amazing how marketing can infer things that cause people to jump to the wrong conclusions. There are of course exceptions. Synthetic oils intended for racing like AMSOil, Nulon and Royal Purple are going to be different indeed. Those oils are far superior compared to Syntec, SynPower and Platinum but because they are racing oils, they are technically a different market and so again, nothing is rated higher in the "consumer" category. People who use AMSOil, Nulon or Royal Purple in their daily driving vehicles are literally flushing their money down the toilet because they'll never use the special properties of those oils that make them so expensive. Consumer Reports did a test of 50 New York taxis with all different brands of oil including conventional, synthetic and re-refined. In the end, they said that they all performed the same. Personally, I use synthetic because I get a good price on it and I use an extended-drain interval because I prefer to not have to change my oil in winter. Therefore, I change it every 6 months. I believe that this is the only real advantage to synthetic oil, longevity. Mix what you want in whatever grades you want. And if anyone tells you NEVER to mix synthetic with conventional because it will damage your engine, try asking them what a semi-synthetic or synthetic blend is. I guarantee you that they will be forced to admit that their knowledge is in fact, limited and they're just spouting some crap that they heard somewhere. Good luck to you!

[Jim Jones]

AA

I have been using synthetic engine oil in my car after the 10,000 km and 10 oil changes, and have been changing them every 10,000 km and six months intervals.

However this year changed to Amsoil, reason being that I have used this product in a diesel engine and its been not a drain of money at all, the truck uses 14.2 litres of oil in one change, even with synthetic oil it would be 28.4 litres a year, by using AMSOIL I have been able to cut the change to once a year and change oil filtre every six months. I do monitor the oil condition also. Now the difference of cost between the common synthetic oil and Amsoil is around $2.50 and estimating that I use the left over from my case of Amsoil 4X3.854=15.416 litres. I end up saving a lot of used oil (42.6 liters mineral oil or 13.8 litres of common synthetic oil) NOT TO MENTION MUCH HIGHER GRADE IN MY ENGINE.

[Avro Arrow]

Jim,

I totally agree with you on that one. The thing is, most people aren't brave enough to change their oil only once a year. I applaud you for it because it's far better for the environment having so much less waste oil. I change my oil twice because I found an incredible deal on Synthetic Oil ($5 per litre) and my car's 12 years old so it helps me keep tabs on whether or not my engine is doing any oil burning. I have 3 cases of the synthetic I currently use so when I finally run out of that (If I still have the car) I'll probably do as yo do. It's just a smart thing to do. My oil filter is in a really nasty place on my engine. I swear I don't know what they were smoking when they designed this but I can't reach the thing from the top at all so I have to put the car on jackstands to change the oil filter. Since I have the car up anyway, it's not a big difference to just drain and fill my crankcase. Newer engines also don't dump as much crap into the oil as older ones like mine do so that might also make a difference. Diesels dump soot into oil and turn in black but those particles are too small to affect an engine in any way. In fact, other than turning oil black, diesels actually dump LESS crap into oil than gas engines do. I really do wish we could have more diesel vehicles in North America because other than trucks and European cars, we don't have any choices. Since I'm not at all impressed with German reliability (and I see what the cost of repairs on them are), it's still far less expensive for me to drive Japanese gasoline-powered vehicles. Again, I applaud you for what you do. You're doing a lot to help the environment as well as saving money. Good man!

[ishie]

Can you mix different brands of snythetic oils?? [ always have some left from last oil change]

are you done for this mixing? i am planning to and i was thinking if autoparts warehouse is the best store for that oils. do you have an idea where is the best store for this?

[nascar jack]

i tend to agree with avro arrow to a point. my father always told me never mix oils and stick to one brand. but i would think it would be ok to mix quaker state and penzoil as they are from the same company as an example. but oil such as royal purple, amsoil and mobile one are out there on there own and i would guess that they use a formula that is exclusive to them so therefore i would not mix them with something else.moble one has been producing synthetic since the early 1970s that i can recall. just my opinion hope this helps.....cheers

[Robert90]

Really if you think about it, not all the oil gets drained during an oil change anyways.
So every time you switch oils your mixing it already.