10w-30

[MysticMirage]

Can you show me a manufacturer's manual for the 3A92 that specifies 85w-140?

I can show a Mitsubishi manual that specifies 10w-30, 10w-40, and higher, up to 20w-50 for the 3A92.

If you are not of my opinion that heavier weight oils are more protective, or you prefer to prioritize for fuel economy, then feel free to run 0W-20 or 0W-0. I am merely sharing my experiences based on my opposite opinion.

The joke. You missed it.

[M-88]

Can you show me a manufacturer's manual for the 3A92 that specifies 85w-140?

I can show a Mitsubishi manual that specifies 10w-30, 10w-40, and higher, up to 20w-50 for the 3A92.

If you are not of my opinion that heavier weight oils are more protective, or you prefer to prioritize for fuel economy, then feel free to run 0W-20 or 0W-0. I am merely sharing my experiences based on my opposite opinion.

I was being facetious, to a point.

There is no evidence that thicker oil is better. This engine was tested for a multitude of oils. 0w-20 is going to work as well as 20w-50, or better.

MOST of an engine's cooling comees from the oil. Thinner oil is able to cool much better than thicker oil. Also - most oil passages for VVT systems can't flow correctly with heavier oil. That may not be the case for this particular engine, but a lot of people got themselves in trouble with the early VVT systems on ford trucks. They made uninformed decisions to run heavier oil "because it's a truck" and screwed up the cam phasers.

on a -30F morning - which I see here quite often - 10w-30 just isn't going to flow well at all whereas 0w-20 flows well.

My Focus is spec'd for a 5w-20 oil, 0w-20 has better cold flow properties so that's what I use in the winter. Likely, once it's old enough to no longer have a powertrain warranty, I'm going to just use 0w-20 at year long intervals. I have UOA data to back up that my particular engine is more than safe running year (10K mile for me) intervals on Mobil 1 or Pennzoil 0w-20 oil.

I don't doubt that the thick oil makes the engine run smoother. Heavier oil will provide additional dampening.

If I had a mirage and , depending on how the warranty would treat it, I would probably run 5w-20 conventional if it was significantly

Now I'm not going to run a 5w-20 oil in my Jeep 4.0 engine. I'm also not going to run a XXw-40 oil in the Jeep engine. Tried that and noticed no difference other than getting some funny noises on extreme cold start because it couldn't flow. I will stick with my SAE30/5w-30/10w-30 blend in it.

The joke. You missed it.

Yeah. I always make that joke. Usually people pick up on it. Running gear oil in an engine would not end well ... the additives would eat the bearings pretty quickly.

[cookiemonster]

I was being facetious, to a point. There is no evidence that thicker oil is better....

I've read in the past some car owners' manuals that have stated that thinner oil gives better fuel efficiency, and thicker oil gives better engine life. I don't know if that is absolute fact or not, but the fact that a few manufacturers (if I remember correctly, Hyundai was one) have actually recorded that sways my opinion that way. So, I'm experimenting within the range Mitsubishi Japan and Mitsubishi Europe recommended. To each his own

[Charlie]

I think Cookiemonster is doing the only thing an individual with a healthy amount of skepticism can do, try it out for themselves.

Cookiemonster is absolutely right in that companies often times make decisions with $ interests the top priority. Subsequent oil viscosity recommendations can not be trusted to be based 100% on engine longevity, which is the consumer's top priority (usually..well, at least for consumers like me who plan to keep the car for over a decade!). The only thing the manufacturer is interested in doing is making sure the car reaches the warranty period, and then that's it. Granted, we have a generous warranty period, but if Cookiemonster is planning on keeping the car forever like I suspect he does, then his experimentation with higher viscosity ratings within recommended range between country region is absolutely appreciated.

The only issue is, after a decade passes and his engine is still doing well, how do we know it is doing better than if he had opted for 0w-20?

With that said, I think I'm sticking with 0w-20, at least for the warranty period..

-Charlie-

[grsupercity]

After the warranty period, its not good to totally change the weight of the oil. Once pass break it, you usually want to keep using the same oil

[cookiemonster]

Yes, I've read about engines liking a consistent oil ... something about the specific mix of detergents and additives that builds up in it might get removed by a different detergent and additive mix from another brand.

[luckyforrest]

I did the first oil change at 7600 KM and 5w-20 conventional oil was used. I found 5W-20 oil makes the engine much quitter and no noticeable difference in MPG so far. I live in Canada, temperature is about -8 degree. I would like to try 10W-30 oil during summer time (May-Oct)

[Mark]

I haven't experimented with various oil viscosities. If you live in a climate where temperatures consistently drop below freezing, 0W-20 oil is the way to go.

Common sense tells me that 5W-30 would be a better option for the summer months, but I am not sure it is necessary. I prefer to do 5,000 mile oil changes. There are two maintenance schedules, & this interval falls somewhere in the middle of them. It's only 3 quarts, & it's so easy to change.

[Tyrelirwin]

As a higher mileage user, I'm pretty sure that anyone with a CVT need not worry about their engine being the failure point. It's cold here, I use Mobil 1 0w-20, change every 10,000kms (about every 50 days). No issues after 278xxx kms.

[chris alan]

Cookiemonster,

Its been 4 years or so since your post about running 10W-30 oil in your mirage, I was wondering how the engine is running?

I have a 2017 mirage (30,000 miles) and have been noticing occasional knocking in very cold weather (Buffalo, ny). Thought it might have been the oil filter I was using (purolator boss), then switched to a wix and still had the same problem. So I changed the oil (Valvoline 0W-20) and put a Mitsu filter on, after 1500 miles it started to knock again occasionally again.

So now i am thinking its the 0W-20 oil that is the culprit. My thoughts are when the oil gets some miles on it and thins out that's when the knock starts. MY suspicion is that the oil gets thinner and either leaks out of the ADB valve in the oil filter back into the engine OR its just too thin to adhere to the engine components.

I would greatly appreciate any feed back cookiemonster!