I have a 2011 Mazda 6; the manual calls for 0w20 synthetic oil. I went to a tire shop to get new tires. The mechanics were ASE certified, so I figured I’d get my oil changed while I was there. I didn’t look at my receipt for about three weeks, and it says that they put in 5w30 conventional oil. Is this OK? Do I need to get my oil changed again?
I would have it drained out and swap to the right oil. It will not hurt anything short term, but I believe you should always use the manufacturer’s recommended oil.
No need to panic and rush out to change it, but do get it changed. Call the shop and explain what happened, do not let them tell you they put the right oil in and just listed it wrong on the receipt. Try to get them to put the correct oil in at no charge. The filter will not need to be replaced.
I’d take it back to them and have it changed in the next few days. I doubt any damage was done, but why push it? Modern engines depend on the oil for both lubrication and running other engine systems, like adjustable cam timing.
OK, thanks. It sounds like you’re all agreeing that I should get it changed to be safe, but I don’t need to rush out right now and get it done. Thanks for the help
If this happened in December and you lived in Minnesota, I would say have it changed right away. Otherwise, go with the advice of the other posters.
Tires guys are usually very stupid on oil. ASE certified does not mean much if the shop’s owner is pushing the cheapest oil available. The 0W20 oil is either full synthetic or a synthetic blend. It costs a lot more than the stuff they put in your car!!
Don’t go back there for anything except tires.
I disagree; I think you should get this stuff out of there now. If you have a lot of short trips, meaning a lot of ambient temperature starts, you might get some engine damage from the too-high viscosity. For that matter, it will be too high when heated up, too. Why risk it? Get the right oil in there. (I wouldn’t worry about the bit left in the filter).
5W30 engine oil won’t harm the engine, if you are outside of the United States you can use 5W30. This is from the owners manual;
(Mexico)
Use SAE 0W-20 engine oil. If SAE 0W-
20 engine oil is not available, use SAE
5W-20, 5W-30 engine oil.
The recommended change interval with 0W-20 is 7500 miles, correct?
I would leave it in until the fall, or 5000 miles, whichever comes first.
I ended up going there this morning to see what I could work out. The guy there tried to convince me that I had a different car than I actually did, and that they put in the oil that their system recommended. This was despite the oil cap and manual saying 0w-20. After some haggling, they did end up changing it for free, though, to the 0w20. I’d still go back there for tires, but definitely not an oil change.
Thanks, Nevada_545. I did see that in the manual, but I wasn’t sure if there was a difference in cars made for Mexico versus the one that I have.
U talked in office. Did u see tech actually put 0-20 in car? Most shops won’t let u in service area.
A reminder that in Mexico, most drivers and most places that sell motor oil actually believe that anything lighter than 20W-50 will destroy your motor. Seriously.f I have even been in an Autozone and there was nothing lighter on the shelves.
Once, I went to a local auto supply store and asked for 10W-30 to have a spare quart for a trip. The young punk shouted at me angrily, as if I were some kind of idiot, telling me I would destroy my motor.
An owner of the local x-ray machine told me the reason they need to use 20W-50 is because the good motors get shipped to the USA, and the ones they use in Mexico are the bad motors coming off the line. I don’t think even GM at its worst (which was very worst) made motors so bad they sorted them into good and bad piles to sell in different markets. (Please don’t suggest it to them, hee, hee.)
Of course, taking good motors and putting in 20W-50 will tend to make good motors into bad motors soon enough, i believe.
If you ever drive in Mexico, change your own oil. Even if you tell them to use 10W-30 or 0W-20, they may agree but go ahead and use 20W-50 believing you are an idiot and they have to save you from your own stupidity.
A few months ago, I checked the oils in Wal-mart and they actually had a few quarts of 0W-20 synthetic, but not Mobil-1. But, there was a lot of 20W-50. I can’t even imagine what might actually need 20W-50. Maybe the old diesel compressors in the quarries.
wouldn’t want to use 20w50 in anything with variable valve timing 
I have been in a similar situation before. Getting wrong oil despite explicitly requesting the correct one. When I complained, the shop foreman just crossed the wrong weight and put in the correct one on the receipt and said that it is just the receipt that is incorrect. And this was a dealer too/car under warranty.
At any rate, I would not trust the shop having changed the oil or using the correct one. For all we know they only have one oil weight in stock (& the ASE logo is from the original owner in the 60’s!). I would get the oil changed somewhere more decent.
@irlandes. I fully understand. And Pemex is not helping the situation through education. We lived in Malaysia for 5 years and the tropical climate there made every service station stock mostly 20W50. I had a Mitsubishi Clone (Proton Waja) which called for5W30 oil, but I had to fight to get it.
These engines made locally were rather loosely designed and 20W50 would not harm it. However new imports form Germany or Japan were serviced by the dealers who stocked the right weight of oil.
You were wise to get this corrected imo OP. Good for you for being persistent. If you were in Mexico it would be better to use the wrong oil than no oil change at all. But you aren’t in Mexico.
If you were in Mexico it would be better to use the wrong oil than no oil change at all.
George, 5W30 is not he wrong oil in Mexico, outside the United States you have a choice of oil weights, there is no need to follow EPA requirements. Owners manuals are required to list the oil type/weight the was used during certification tests.
Used 20W -50 in an old very worn 8N Ford tractor .worked very well.
It’s clear from the Mazda Owner’s manual that 5w-30 is an acceptable alternative for this engine. If it were me, I’d leave it in there till the next oil change is due, (or till November if I lived in a cold northern climate).
Kevin, that old 8N tractor would correspond to the old compressors they have here, except the compressors are often diesel, since they may run all day long.
We can’t simply dismiss at as “Mexico”. The USA has its own share of insane things. This is just one where Mexico is wrong.