Dealership Changed Oil... to Synthetic
 

First off, I'd appreciate if this thread stayed on topic and remained relevant. Not to sound like a jerk or anything, but we have enough dino vs synthetic oil threads. No need for another.

That being said, a few days ago my dad took the 8 to the mazda dealership to have the oil changed, tires rotated, etc. This is the first time we have had the oil changed since we bought it. Up until now I have trusted this dealer, as we bought it from the dealership's ford branch who lied about the heater working. (It was having the problem with flip flopping from hot to cold to luke warm to cold) The mazda branch of this dealership not only fixed this but also fixed the heated seat switches, as one didn't always work and the other wasn't seated correctly. They seemed to be pretty decent guys.

So, after getting the car back and going over the bill with my dad, I noticed that they changed the oil fine, but to synthetic. (5w20) What happened to, "Synthetic will void your warranty with mazda, blah blah blah." Not that there is a warranty to void, but still, I try to go with what the manual recommends. Is mazda starting to relax their firm no synthetic policy in the US? :uhh: Or does this dealer just not know their stuff?

I poked around the site and didn't fine much, apart from a thread asking the same thing I am, but it turned out to be mistake on the dealer's part, in regards to meaning the oil was for another car, IIRC.

So, anyone else have this happen? (Sorry for the long post)

In all honesty, since the dealership did it, keep that receipt. I can't see any reason that they can void your warranty if it was the dealership that screwed up. Keep it on record and you should be OK.

I think not only dealers are fine with synthetic but they also recommend it for rotary. When I bought my car I went to 2 dealers in my area and one of them is using full synthetic and the other one is using synthetic blend. When I was asking, I made sure they know the model of my car and that it is rotary. Actually one of them bring out the tech and he started explaining that synthetic is better for rotaries and that's why they are using it. So in my opinion since lots of dealers are using synthetic it should not void the warranty.

BTW please let me know where Mazda have no synthetic policy in the US? Can you tell me what page of car manual you are referring to cause I never see it.

year and mileage of your car. what exactly does the receipt say? did you ask the dealership about it?

Is there anyway to tell by removing the dip stick wheter it is synthetic or regular oil.

You have a problem if they used synthetic as the mixed your oil.

You have to drain every drop before you switch, which means diconection of the oil coolers and draining.

For 2007 MY (and later) Mazda added this to US/Canadian Manuals

https://www.rx8club.com/attachment.p...1&d=1285614637

Good to know that. I can go back to the dealers and show that to them and see what they are saying but I do not know if that's a good idea. I have good relationship with one of them and they might not honor warranty repair later on if needed.:uhh: Also they might say you have 04 and it is good for 04.:cwm27:

Good. Thank them for filling your car up with it and just come to terms with the fact that conventional oil is quickly becoming a thing of the past.

If we got anything out of the synth vs dino oil threads, it's that not all synth is made equal. The question is what sort of oil mazda uses.. if it's rotary safe or if it gums things up. If you believe that you're better of with dino, bring it back to the dealer (since the car has yet been hardly driven), point out their mistake and ask them to fix it. Keep all receipts so that if ever you need to prove anything (the 8/100 warranty...), you have a solid case. The dealer keeps records too you know.

I want to know where the myth came from that you have to drain ALL the "dino" oil out before adding any "synthetic" oil? Anything I have ever read on the topic says they are pretty much all compatable except maybe a few exotic synthetics.

Wait. The OP said they used 5w20. And the manual reads use 5w20. Im confused...

they used a semi-synth which the manual for his year says is not to be used.

of course- try finding a 5/20 that isnt semi-synth... Mazda Australia had to buy in special oil for rx-8s because they were handing out those memos that said no synth and then all the Mazda dealers were stocked with only synth.

Mazda Australia is loaded with morons. more than MNAO actually.

Whoever said Rotary does not work with Synthetic oil deserves a slap in their face.

I don't know, its just weird, Mazda Japan use and have their Synthetic oil for Rotary Engine. but for some weird reason the rest of the Mazda is sooooo afraid of Synthetic like its some sort of diseases. and don't give me that not all synthetic are created equal. they're not, but these days as long as it reach the rating, it will NOT be worst than any mineral oils of the same rating.

OK, I look at it this way and correct me if I am wrong because I do not have physics degree.:o: For making synthetic oil they get a molecule of a mineral oil and then through chemical process in laboratory they expand that molecule and make the oil (or they might create that first molecule through chemical process). So if anything, synthetic oils should have more uniform structure and less unwanted material in it. In other word should burn better and leave less carbon behind?:dunno:

cept oil isnt just oil, its got chemical stabilizers in it to make it a multi-grade oil. some of the chemical might solidified under high pressure and heat.

I completely agree. So 5w20 synthetic should have almost the same stabilizers as 5w20 mineral oil.:dunno: BTW I did not understand if you are agreeing with me or not.:scratchhe

And this I know for a fact that the closer the range is, less stabilizer and junk they add to it, so it is better. It is even better to change oil grades for winter and summer instead of using wide range oil throughout the year.

Use diesel engine oil

Oops, looks like this turned into a mineral vs synthetic oil debate.

The benefits of synthetic vs mineral oil have been well documented and well debated on several threads. The basic elements to remember are this:

Mazda cannot determine what kind of oil you are using unless it is tested. No one can smell, look or otherwise physically examine engine oil and tell you whether its mineral or synthetic oil without lab testing. Last I checked, most dealerships have problems getting oil into your engine so the thought of them testing it for warranty purposes is science fiction.

When it comes to running synthetic or mineral oil, the decision on which to use comes down to your change interval. People who change their oil frequently (less than 3,000 miles) can easily get away with using mineral oil. Synthetics are designed for longer change intervals and a wider range of operational conditions. My opinion is synthetic oils are a good idea considering about 1/3 of your oil doesn't get changed.

I wouldn't worry about a single oil change done by the dealership. Your concerned over a single change instance done by a Mazda dealer that I doubt could be used to void your warranty. Then again, Mazda has denied the replacement of a Mazdaspeed Protege motor on the basis that my friend's oil "smelled funny". So I guess anything is possible.

I go with whatever Flashwing says. I agree with him and his sig says BHR so you can't go wrong.;)

75 disparos

:dunno::Peace:

I dare to make a slight direction change in this thread and ask for opinions on making a switch from conventional to synthetic. I hope to possibly give the OP a different perspective on whether to continue synthetic use with or revert to conventional. This is also of course in personal interest to gather others' opinions.

My vague and fuzzy understanding is that conventional oils can tend to leave comparatively more deposits over time. These deposits assist with sealing efficacy, masking wear to the seals and/or chamber walls.

Synthetics tend to clean out said deposits. In the case of an engine that has seen only conventional oil since the beginning of and through a fair amount its life (let's say, from 0-70k+ miles), changing to synthetic will expose any wear in the engine that was already there.

My pondering would be to what degree this effect may be observed. If it is deemed detrimental to the particular case, is it reversible? I.e. if it turns out synthetic oil is causing too much of a compression loss, is it possible to go back to conventional in an attempt to get deposits back and in effect, compression? What's even the validity of this theory?

WTB BHR signature!!!

Khaf- Thanks for putting my mind at ease. Nice to know the dealer isn't just going around doing their own thing. Maybe Mazda is gradually easing off the whole "mineral is the best" policy.

zoom44- 2005 with 40,000 miles.

Well, Ill just keep using the synthetic oil and prolly switch to a different around 70,000 miles, when the time comes.

Actually it's a synthetic blend oil. Castrol 5w20 syntec blend, i think is the name. Seems ok, the engine even runs slightly cooler. (Only half a tick down from the usual temp level, if that.)

My question now is whether or not having the synthetic oil mix with the amount of regular mineral oil is going to be ok? It doesn't seem like a horrible thing, but I'd appreciate any input you guys have.

Finally, I'll ask the mazda dealer tech guy if mazda is saying anything official about the oil. I have to take the 8 back anyway because a suspected problem with the u joint. (The car shakes and thuds while driving at any speed, and you can hear a lot of squeaking. Kinda like having a stone in the tire, but many times more violent and much louder.)

Oh, and one more question. Everyone keeps talking about the warranty being voided and such. To the furthest extent of my knowledge, there is no warranty on my car. Or is there some global/general engine warranty that I'm just missing? Thanks guys!

if for temp you are talking about the gauge on the dash then you are mistaken. once at "operating temp" it wont show you anything unless the temp gets about 200 degrees hotter. if it really is showing a tick lower that is a gauge glitch(needle sticking) and nothing to do with actual temp change.

no worries with mixing the different oils


the engine core has an extended warranty from Mazda. 8 years or 100k miles https://www.rx8club.com/rx-8-discussion-3/8-years-100-000-mi-extended-warranty-147287/