- :
- San Antonio, Texas
- :
- '15 CX-5 Miata AWD
Can't really comment on sound because i made the switch around the same time I got a new trans. Vibes etc not applicable to me because of mods. Mpgs don't seem any different.
2.5L Oil level fluctuation
- Thread starter Sekmor
- Start date
Can't really comment on sound because i made the switch around the same time I got a new trans. Vibes etc not applicable to me because of mods. Mpgs don't seem any different.
GJ-Molestor
Banned
- :
- 2011 BMW 528i, 2015 Mazda 6, 1995 Nissan Maxima Manual
Strongly agreed, I noticed the exact same thing when I made the switch to 5w30. I mainly did it because it stopped 99% of the oil consumption I was having. Oil level is still almost full in between oil changes now.
Theres a roughly .2MPG difference, so not much to comment there. If your engine burns some oil, it will run noticeably smoother with 5w30 but regardless you will notice a difference with how the engine runs with the hood up. Less valvetrain clatter. Engine felt a lot more refined, smooth quiet to me after making the switch.
- :
- 2016.5 CX-5 GT AWD titanium/black 2016 Miata Club ST MT white
Not sure if this applies to gasoline engines but with diesels the oil turning black is a good thing. It shows that the oil is doing it's job and suspending the particles in solution.
FYI YMMV
Same thing for gas engines, you can't really gauge by color. It shows the detergent in the oil is trapping dirt and carrying it to the oil filter.
I have contemplated replacing the recommended 0w20 with 5w30 synthetic in my 2013 cx5, but the Mazda dealership cautioned me on doing this. But I do get tired of checking my oil daily in the winter months. The best thing I have done to date is cover the front and drive the cx5 in manual mode and keep the revs up around town. It seems to keep the engine oil from rising too fast because of being diluted by gas. I might try the 5w30 for a month and see if it helps.
Are your driving habits such as they are contributing to fuel dilution of the oil, ie short tripping?
If so switching to 5w-30 doesn’t solve anything but is just a bandaid. I do lots of short tripping but I run Shell premium fuel. I check the dipstick often and have not had any change in oil levels. The oil does not have any fuel smell either. I also try to run the car for a longer trip at least once a week. I’m still on the factory 0w-20 Idemitsu oil.
I keep it in an insulated garage and my wife drives it a total of 20 km a day. 10 km of that is highway speed. She keeps it in 5th gear at highway speed to keep the revs up. This has helped, but still does not seem to be enough to keep the oil from rising. If I drive 300 km then I notice the oil come back down to full. This is my 4th winter and there has been no change. I have had my CX5 into the local dealership regarding this issue and have also contacted many Mazda dealerships. They have no answers. I still am willing to explore other solutions. I think I tried a tank of premium fuel and there was no change.
The oil temperature in our CX-5 rarely goes above 90C, even during a day-long driving on the highway, and it takes about half an hour to get there. This is barely enough to gradually evaporate gas and water out if the suspension in oil. With city driving or short highway runs, the oil temperature stays way down in 50-60C range, even less in the winter. That's not enough to persuade gas to evaporate out of the oil in a rush. It keeps coming faster then it evaporates.
Regardless, there is no tangible evidence that fuel dilution harms the engine in any measurable way. Lots of UOAs from our engines and competition on bobistheoilguy.com, all look great by wear metals. People there that run premium on the regular basis report no or reduced fuel dilution, which makes sense, at least theoretically. I'm just too damn cheap to try it myself...
Regardless, there is no tangible evidence that fuel dilution harms the engine in any measurable way. Lots of UOAs from our engines and competition on bobistheoilguy.com, all look great by wear metals. People there that run premium on the regular basis report no or reduced fuel dilution, which makes sense, at least theoretically. I'm just too damn cheap to try it myself...
Last edited:
There may be no evidence that oil dilution harms the engine, but I still am not sure how high to let it rise on the dipstick before either changing the oil and filter or going on a long trip. Either way it costs the same. I have let the diluted oil rise to the twist on the dipstick before I took action.
I hear you, and it looks like your case is worse then ours. However, on a flip side, I have not read about seals blown out or any other high-oil-level- related accidents. Think about it, how many people ever check oil level? This is a very foreign concept here in Canada, and in the US. I have an experience, through five years of repair shop ownership in the past. So we know that the oil level goes up in most DI engines, Mazdas, Toyotas, Hondas, Chevys... How many of them are driving around with sometimes quite a bit stretched oil change intervals, even outright neglected? People are too busy to to want to know about their oil levels and importance of oil changes.
Yet we keep rolling. And, for the most part, it is valve deposits that impede pure DI engines, not oil level or fuel dilution.
By the way, I have personally seen the Jeep with about twice the amount of oil running the full OCI. We figured, the quick lube place didn't drain oil few months ago or the owner kept adding oil, thinking it burns. Nothing terminal, new oil and filter in, and the owner just shrugged it off. The car didn't care either.
Yet we keep rolling. And, for the most part, it is valve deposits that impede pure DI engines, not oil level or fuel dilution.
By the way, I have personally seen the Jeep with about twice the amount of oil running the full OCI. We figured, the quick lube place didn't drain oil few months ago or the owner kept adding oil, thinking it burns. Nothing terminal, new oil and filter in, and the owner just shrugged it off. The car didn't care either.
Yugru is correct. If you head over to Bob Is The Oil Guy, you can read a number of uoa’s that showed high fuel dilution numbers yet the wear metal numbers were excellent. Today’s oils are much better in handling this. With that said, I wouldn’t go over 5k with any oil.
