Mixing 5w20 With 5w30 Or Dino With Synthetic

Status
Not open for further replies.
Joined
Jul 23, 2008
Messages
9,808
Location
New Jersey
Does anyone mix their own oil say a 5w20 platinum with a quart or two of 5w30 platinum? Or say a dino 5w20 with a dino 5w30 of the same brand to maybe get a little higher viscosity but not quite a 5w30?

I saw today one of the guys here owns a 2004 ford truck with the 4.6 v8 and he intentionally mixes 5w20 and 5w30 Quaker State synthetic ud.. the engine calls for a 5w20 but he mixes in 2 quarts of quaker state ud 5w30 the engine has about 60,000 miles on it..
He has been rebuilding engine for over 25 years and he knows his stuff when it comes to engines..
 
What are you trying to accomplish.

Quote:

He has been rebuilding engine for over 25 years and he knows his stuff when it comes to engines..


What about oil?

I don't see much benefit to mixing oils IMHO.
 
I never mixed 5w20 with 5w30 but I have mixed 5w30 with 10w30. I didn't mix in order to get a different final product but just in top offs.

At work we dump regular old 5w20 in every Ford that it calls for. So a E250 for example gets 5w20 and achieves many many miles (greater than 150k). I'm not convinced thicker oil (than recommended by the manufacture) necessarily yields in longer service life of an engine.
 
I do it all of the time, I think it accomplishes a slightly more robust 5w20, especially when I am going to put the car through some tough driving or a FL summer. I don't think it will do too much but I definitely don't think it can harm anything. Mix away I say! To each his own.
 
You can mix viscosities among the same type of oil, though I don't understand the purpose of intentionally mixing...there isn't a big benefit...for top off it's OK. "More robust 5W20"? Check the viscosity chart...not a big difference, so why not buy the 5W30? Thicker isn't better, it's a matter of required viscosity based on bearing clearance and operating oil temperature. If your oil temp requires higher viscosity than recommended, then go ahead...but how many cars have an oil temp gauge to determine that? My old Volvo did...and even in summer heat, the oil temp was pretty consistent. The oil temp did climb during heavy use of the turbo - mountain driving, towing, that sort of use.

If you track your car (racing...) then get an oil temp gauge and monitor it...but for 99.9% of the vehicles and conditions out there...it's not needed...

I wouldn't go mixing synthetic with dino - again, what are you trying to accomplish? If it's an emergency to bring the oil level up to acceptable, I would rather have a mix than run on low level...

Any time you mix, keep them the same family. For example, Castrol GTX with Castrol Syntec. I wouldn't mix across brands - different additive chemistry could cause a problem because of incompatibility...you could degrade the performance of the additive package...

I am still stuck on "why"...pick the recommended viscosity in your favorite brand and be done with it...
 
Last edited:
Originally Posted By: crazyoildude
Does anyone mix their own oil say a 5w20 platinum with a quart or two of 5w30 platinum? Or say a dino 5w20 with a dino 5w30 of the same brand to maybe get a little higher viscosity but not quite a 5w30?

I saw today one of the guys here owns a 2004 ford truck with the 4.6 v8 and he intentionally mixes 5w20 and 5w30 Quaker State synthetic ud.. the engine calls for a 5w20 but he mixes in 2 quarts of quaker state ud 5w30 the engine has about 60,000 miles on it..
He has been rebuilding engine for over 25 years and he knows his stuff when it comes to engines..



I see no harm in it at all. I would stick to the mfg spec grade of oil, but if he has some oil burning issues and wants to "thicken" the oil a bit why not? I also think you can mix dino and synthetic and come up with a better blend than buying one. Once again if you decide to go that route. JMO
 
What am I trying to accomplish ?? Nothing.....
Just curious as to how many people do this.. im sure it wont hurt anything but i wonder why people do this he says he just wants the oil a little more robust..
 
People ask this all the time
laugh.gif
 
I can't see any point at all. If the oil company chemist thought they could make a "more robust" oil, I have to think they would do it in their own labs. I don't think I put to much faith in a garage chemist.
 
Mixed plenty of times. 5w20 or 5w30 most engines won't notice a difference. If you're car calls for 6.5 quarts of either, and you grab 7qts off the shelf, but don't notice that some are different weights until you get home, do you drive back to the store? I won't drive back to the store and just use the oil.

I don't intentionally do it as there usually is no point to mixing as that so-called 'guy' does. My engines never need rebuilding so I wouldn't trust an "guy that has rebuilt engines for 25 years" .
 
I'm going to be changing the oil in both my vehicles in about 5 months. The Caravan will get 5 quarts of Mobil 5W-20 EP and the GS400 will get 5 quarts of Mobil 0W-40. Now the capacity for both vehicles is about 5 1/2 quarts and so they both will get about 1/2 quart of Mobil 5W-30 EP. Also, since I do a yearly OCI any top off will be the same 5W-30. However, neither car really burns much oil---I'll probably just add another 1/2 quart for top-off.
 
I've heard of people using Red Line as an additive. I think there was someone who mixed RL with Havoline and it produced some pretty good UOAs.

I've never seen nor ever heard of problems caused by different additive chemistries, too many people do it without problems for it to be an issue.
 
a guy gave me 4 qts of vwb 10/40 and my truck takes 7. so i went and bought a jug of vwb 5/20 and added two qts of 10/40 to it.
worked out great! i got an oil change for 15 bucks. (wish i would have stocked up, vwb went from 11 to 13 at my wm)
 
I mix all the time if I've got "odds and ends" of oil around and need an oil change. 1/2 a quart of this and a quart of that to get me up to 6 quarts of fresh oil. I've never had a problem mixing oils of different brands, grades or Dino with Synthetic. To me.....it's all oil and will serve a purpose....if you need some fresh oil for an oil change and have all sorts of oil, capped or sealed.....might as well use it all up and be done with it.
 
I mix mostly to boost the additive pack and viscosity of 5w30. My LS1 takes 6.5 qts and I add two qts of 15w50 to 5w30 to thicken it for the desert heat. Instead of the 11.1 operating temp viscosity of the M1 5w30, I get 13.2.
 
Everyone know that I mix oils.
I mix based on the oils that I have in my stash.
Usually 2qts syn with 3qts dino. And, I have mixed different syn brands/weights and the same with dino.
Mostly, I'm just trying to balance out my stash, not trying to outsmart the engineers.

Prior to discovering BITOG, I would never use synthetic oils...Too expensive! But, now I have found all of the sales/discounts/closeouts because of the Product Rebates, Sales & Promotions Section.

I could line up all of my "same brand/grade/dino/syn" all in a row for OCI's and then use up all of the orphans seperatly. Instead, I just try to create a balance of 2 syn to 3 dino for all of my OCI's. But, even it may vary from time to time. For example:

I may use 2 same syn and 3 different dino or visa-versa or any combo. I have done something along the line of, e.g.:

1 PP 5W30
1 QSTP 10W30
1 VWB 5W30
2 PYB 5W30
 
Status
Not open for further replies.
Back
Top