My wife's 2018 Mazda6 (with the 2.5 turbo) consumes about a quart of oil every 5000-7000 miles. Basically the oil light comes on right about the time an oil change is due. This is our first car with a turbocharger, so I'm not sure if that's to be expected or if something else is going on. The car has around 25,000 miles and gets used most often for short trips.
Do we have anything to worry about?
In reply to thatsnowinnebago :
As a data point for you, my wife has the CX-9 with the same engine, and it doesn't show any noticeable oil use between changes. Ours is a 2016, and has 70,000 miles.
I'm not an expert, so I'll leave others to offer ideas and advice!
Definitely not an expert either, but I've heard some people complaining about the turbo 2.5 engines consuming oil on some Mazda forums. About the same amount you're describing. I don't know much about it, but someone mentioned valve stem seals. Seems to be exclusive the turbo motors from what I've heard.
I wish I knew more, but I don't. Mazdas247 has pages of content about it. Not spent enough time on there to be sure about the knowledge of crowd there, though.
CyberEricI wish I knew more, but I don't. Mazdas247 has pages of content about it. Not spent enough time on there to be sure about the knowledge of crowd there, though.
Wow. I just spent 10 minutes reading that forum....it makes me want to sell my CX9 now, before it breaks....there are tons of thread on engine replacements.
In reply to CyberEric :
I saw some threads about a recall on 2021s for the valve stem seals but nothing for older models.
Gotcha. Maybe it wasn't just MY '21 that had the issue. Any smoke out the tail pipe ever?
Let us know what you find if you learn anything more, I'm interested. The non turbo 2.5 is generally very well regarded, and I'm wondering what the deal is with the turbo...sort of like to own one down the road.
What is the factory oil change interval? I notice I find myself thinking 5-7k miles seems like a lot between oil changes. I tend to change my oil every 3k-4k miles so I'd probably not even notice if I had this engine. But I get I'm out of date on oil changes.
You mention that the car is used mostly for short trips, given that I'd recommend changing the oil every 5,000 miles or sooner just based on the short trips. That would "solve" the oil light coming on problem. 
I'm not a fan of some manufacturers long oil change intervals, even 7,500 miles seems extreme to me and I know there are some out there with 10,000 miles recommended. (I'll get off your lawn now.)
Mazda Canada has a shorter oil change interval, compared to USA...ours is 5000M, versus 7500 for USA.
Maybe I'm just outdated, but 12,000km on an oil change seems really long, especially on a turbo.
11GTCS said:You mention that the car is used mostly for short trips, given that I'd recommend changing the oil every 5,000 miles or sooner just based on the short trips. That would "solve" the oil light coming on problem.
To expand on this, all GDI engines end up with fuel in the oil. IT's part of the process when you are literally spraying atomized fuel directly into the combustion chamber. Short trips only exacerbate that issue as it never gives the oil time to get up to temp and "burn off" some of those extra hydrocarbons. This then thins the oil out allowing it to slip past the rings and burn a little. 1 quart every 5-7k miles is perfectly acceptable. Hell, Honda still thinks 1 qt every 1k is fine.
If it's truly doing short drive cycles you will need to shorten the OCI's to compensate.
Bibs said:Mazda Canada has a shorter oil change interval, compared to USA...ours is 5000M, versus 7500 for USA.
Maybe I'm just outdated, but 12,000km on an oil change seems really long, especially on a turbo.
On modern oil it's not*.
* Some conditions do apply. Sump capacity, driving style and oil being used all factor into that.
Modern engines should be limiting their oil burn to more than 10k miles/qt. This is pretty required to make the modern emissions requirements- which, roughly, is 150k miles. So 5k/qt is pretty darned high. And Bob's point about direct injection engines is part of that- the oil dilution due to DI is very well known and has been included in the requirement and any design around making it that long.
Hopefully, this specific engine it outside the norm for Mazda.
bobzilla said:Bibs said:Mazda Canada has a shorter oil change interval, compared to USA...ours is 5000M, versus 7500 for USA.
Maybe I'm just outdated, but 12,000km on an oil change seems really long, especially on a turbo.On modern oil it's not*.
* Some conditions do apply. Sump capacity, driving style and oil being used all factor into that.
Another +1. It's ok that people change their oil more often, and dealers love it. But it's not required. Lots of engineering on both the engine and oil side have increased the desired oil change interval to 10k miles required. (and that was mostly driven by European drivers instead of the US)
I honestly have been following the car's idea of when to change the oil, instead of a set interval, hence the mile range above. There's a setting in the car for something like variable changes.
There's no smoke or anything out of the tailpipe and the underside is clean.
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