Here's the next UOA of my friend's 16 Mazda CX-5 2.5L Skyactiv engine. Both the oil and filter were replaced, filter is a Mazda 1WPE-14-302. The last oil test showed that the fuel dilution was over 5% and from everyone's input I thought it was most likely the short trip driving and the longer oil change interval. Since this is a direct injection engine, the shorter interval definitely lowered the fuel dilution! Was thinking of changing to Mobil 1 ESP 0w-30 but so far the currently being used M1 advance full synthetic (regular M1) looks good, but I welcome any opinions on this test result. I was a little concerned with the tin going up, but this is PPM, so maybe not a big deal?
Mobil 1 5w-30; 2016 Mazda CX-5 73k mi
- Thread starter researcher
- Start date
According to the report, the last interval was *shorter*, not longer. This interval = 2455 miles. Last interval = 2300 miles.
the period of time was shorter this time, 4 months for the oil change interval instead of the previous time of around 5.5 months.
Thats a lot of fuel dillution for that short a miles. Must be a lot of idling, like, a lot. Try and get this car on the highway a couple of times a week, should help it out a lot.
Thanks for the advice, what's ironic is that is mostly all highway miles on that interval! 95% highway and 5% city. And there isn't any idling at all. I was just happy that the fuel dilution went down to 2.8% this time. I know direct injection engines have the fuel dilution problem (if they don't have a secondary port injection system) so I thought lowering the amount of time the oil was in there would help, it did lower it. See I'm not sure if these direct injection engines get diluted with fuel in time or mileage.
Let's say that 4,000 miles was driven for 4 months. All highway miles. Makes me wonder if the fuel dilution would be the same for 2500 miles and 4 months. Guess that's something I'll have to dig into.
Some more info about this.. Dug into the owner's manual online and found some interesting info, I didn't see this before, should've looked!. Mazda lists under the Severe maintenance schedule (which I would always follow no matter what) it says to change the oil every 4 months or 5k miles! This is cool, I ended up doing just that for my friend's vehicle. In Mexico it's 3 months or 5k kilometers (3106 miles) that's even more interesting, shorter miles and time!
If lake speeds videos holds merit he explains that fuel is hard to burn off. I think it's still recommended to drive a bit before taking a sample of oil though.
Are you wanting to extend the mileage or are you staying with <3k?
For my friend, they'd rather keep the fuel out of the oil. I'm betting they're going to change it every 3-4 months regardless of the mileage. I had been questioning how best to deal with the fuel dilution, so I had them do the oil analysis because I needed a base line to understand how this Mazda system would work. I'm used to port injection, nothing to worry about there unless you have a leaky fuel injector.
With looking at the results at 5.5 months I told them to cut it shorter to 4 months, only a guess on my part. And the oil test looked a lot better. But then I did more digging (should've done it before but oh well) and here I find the owner's manual where Mazda is saying 4months or 5k miles for the oil change! That definitely answers my question, Mazda knows exactly how long that oil can be in there before the dilution takes over.
What's also interesting as I mentioned earlier, for CX-5's in Mexico it should be 3 months or around 3k miles! Wow even shorter interval for that region.
And thanks for that info about lake speed's videos, it does make sense it's hard to get that much fuel.