Posting to ask if I could encounter problems by mixing Valvoline 5w 20 and Quaker State 5w 20 to perform a current oil change on my 2008 Hyundai Elantra?
No doubt have ended up with extra of both as I buy in 5 qt jugs and neither vehicle I use this weight oil in requires a full five quarts.
Does either vehicle use any oil between changes. If one or both does, I would use the odd brand for make up, but for the initial fill, most people think no although that may not actually be a problem, just most people I know would not mix on the initial fill.
Except me, I have done that before with no issues. I have mixed Mobil and Pennzoil together.
Edit: did it with Shell and Pennzoil once also.
As long as both brands of oil conform to the SN standard, there shouldn’t be any problem for either the OP or his engine.
http://www.aa1car.com/library/api_motor_oil_classifications.htm
Any oil change is a good oil change, as long as both meet specs, re dollar store non spec oil, it should be fine
Not ever worried before, but I saw the light
Edit I ain’t a particularly religious guy, but enjoy the music 
Edit I ain’t a particularly religious gu, but enjoy the music
As long as they both meet SAE and API specs, and Valvoline and Quaker State both do, AND they meet the specs for your car (you do NOT want to be mixing in 40 year oil) there’s absolutely no concern whatsoever. They’ll mix absolutely without problem.
One thing to avoid is fleamarket oil… and be very, very careful with dollar store oil. The fleamarket oil could be very old and the dollar store oil could be counterfeit.
Any recent brand name is OK. This oil is very common, and unless you have a European car which requires a special oil, any brand of the same weight is OK.
As mentioned, don’t buy any flea market or brand “XXX” oil.
Two reasons why motor oils must be compatible:
You as a motor oil company want your product to work with all others. Imagine the difficulty when you might need a quart of oil during a trip and did not have your own supply.
The military needs compatibility. While fighting a war, your truck or whatever might need a quart of oil and there is no time for fussing about the brand and weight.
Furthermore, I have been mixing two and often three brands in my old VW diesel with over 300k miles. It has done well; burns less than a quart between changes if not pushed too hard.
neither uses any oil between changes and both were bought at my local Wal Mart within the last year.
Did the OP just infer that both vehicles do not use oil between changes and he bought them at WALMART ?
Bought the vehicles at WalMart ??
Wha who, the military has needs beyond those of the civilian world. While supply lines are a major concern in the military and justifiably receive as much of not more planning and resources than the infantry, the military needs vehicles that aren’t fussy about their fluids. An invading ground force cannot be stopped from invading a hostile land because of a sensitivity to a specific fluid need. I wouldn’t want our front lines to stop because only 87 octane gas was available.
That’s one of the reasons that the military uses diesels. They’re much more tolerant of the quality of fuel that might be available in a backward land. And they like turbines for their fuel because they’re also more tolerant of poor fuel and mostly because they’re much quieter. The enemy doesn’t hear them coming from as far away.
Maybe WalMart is now doing what Sears did back in 1952. Sears, in some of the stores, sold a car called the Allstate. The Allstate was a rebadged Henry J which was made by Kaiser. This Allstate had the Allstate tires, and battery and a slightly different grill than the Henry J. In some ways it made sense as Sears already had the service facilities.
As far as mixing oil is concerned, I think it is possible that one refinery in a particular area of the country may be bottling the same oil under different brand names. Some 25 years ago, Consumer Reports tested motor oils and found that the same brand of oil purchased in one part of the country was different than the same brand purchased in another part of the country. I would bet the myth about not mixing brands of oil and sticking with a,particular brand was perpetuated by the oil companies.
Heck, Sears used to sell HOUSES out of their catalog, so why not cars?
Triedaq, I have absolutely no doubt that the myth about not mixing oil was probably originated by the oil companies.
There were some interesting names attached to some brands of motor oil. There was Gulf Single G (Single G was a famous harness race horse), Shell Fire and Ice, Phillips 66 Tropartic, Standard Super Permalube, MacMillan Ring Free, Marathon MileMaker, Quaker State SuperBlend, Sinclair Dino Supreme. It’s no fun buying oil today without colorful names.
LOL, and back then a guy used to come out of the gas station house, fill the tank, wash the windshield, check the oil, and even wish you a nice day.
@ the same mountainbike. The Texaco slogan: “You can trust your car to the man who wears,the star”. The slogan at the Sunoco station where I worked : " You can bet your a** I’m the boy who pumped the gas".
@“the same mountainbike”, gas stations still operate that way in Japan. They might still in NJ, too.
Triedaq, I love it!
I’m sure there are other countries besides Japan where that kind of service still exists. NJ would surprise me if they did. I made many trips to NJ (at least once a month for meetings) when I was in the manufacturing industry, and I thought they were too busy running too fast to catch up with life to be bothered with niceties. But, then, I’m not by nature a city boy. High anxiety levels don’t become me.
Thanks to all for clearly calling me out about buying my vehicles at Wal Mart. For clarification what I was trying to say was that i had bought both brands of the motor oil at Wal Mart and not the vehicles.
While still here the vehicles I have are a 2008 Elantra with 75k and 2004 Sienna with 102k miles respectively. Neither uses oil between changes. As a reule of thumb mileage on the Elantra is a roughly 30 mile rt commute to/from work with some time sitting in stop and go conditions currently in Austin,Texas where summer time temps will reach 100 F or higher
The Sienna is used primarily for errands of 20 miles or less one way with most totaling 10 to 15 miles and mostly at surface street speeds of 40mph or slower.
All this to ask if there is any reason I should consider changing to a high mileage oil or even a synthetic for either or both vehicles? I do change oil and filters at 3000k intervals due to having more of a start/stop pattern than strictly unimpeded highway conditions.
I need to change both currently so any quick input is appreciated
Thanks
“High mileage” oils have chemicals in them to swell seals in order to reduce/stop oil leaks. Not needed if you don’t have oil leaks, and it’s better to fix the leak, if it’s enough to worry about. Since your cars don’t require oil between changes (I assume you check to be sure), they must not leak much, if any. So no, you don’t need the ‘high mile’ oils. As for synthetics, they’ll be no better than what you’re doing.