M1 0-20 in miata

[Cujet]

I have a 94 Miata "R" package. I recently removed the Aerodyne turbo (self contained oil system) because of seizure. So at this point, I am back to the stock setup with a stand alone engine management computer.

I went from having 300HP to 93, kinda ard to take

So in an attempt at slightly more power I put in Mobil 1, 0-20. The first thing I noticed is that the oil leaked out of each plastic bottle by the time I got home. I guess it really is thin.

Oil pressure is slightly lower than my previous oil, a 50% blend of 10-30 and 15-50 M1. The engine is ever so slightly more revvy and seems to require less throttle during cruise. But the big issue is that I cannot notice any more power and top speed did not change (105 indicated). Even the fuel economy seems to be unaffected by the change. I can generally bank on getting 265-269 miles per tank, when filled to the top. I am still very close to those numbers and have not been able to achieve 270 miles. I figured that a 2 or 3% change would result. I guess will let the oil remain for 2500 miles and do a UOA. Should be interesting.

What do you guys think about the protection afforded by such a thin oil. The Miata engine is long lasting and tough. But the thrust bearing can become an issue. I would guess the thin oil does not protect the thrust bearing as well.

Chris

[ July 20, 2003, 10:45 AM: Message edited by: Cujet ]

 

[buster]

quote:

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Applications
Mobil 1 0W-20 is recommended for all types of modern vehicles, especially high-performance turbo-charged 4 and 6 cylinder gasoline and diesel multi-valve fuel injected engines including those found in passenger cars, light vans and trucks.

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This is what Mobil claims on there website about the 0w-20. Mobil needs to address the bottle issues. They are the worst. They need to make the caps fit on tighter and thread them better.

I think your UOA should be interesting. IMO, I think it's a good choice. I have confidence in the new 20wts.

 

[pscholte]

quote:

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Originally posted by buster:

Applications
Mobil needs to address the bottle issues. They are the worst. They need to make the caps fit on tighter and thread them better.

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Buster find your comment on Mobil 1 bottles interesting...I believe every bottle of German Castrol I've gotten has had a cap loose to some degree--some markedly so--and on a couple, the breakaway ring that shows the bottle has not been opened were significantly contorted. Don't know if it is a significant issue, but I don't like it.

 

[cheetahdriver]

am currently using the 0w-40 in my miata, but the 0w-20 has been calling me. miatas love thinner oils on startup as they have a well diserved rep for HLA noise. since i switched to the 0w-xx oils (0w-30 to start with) this has been a non-issue. i have to agree with buster, this oil may be a winner with miatas. look forward to your analysis, and would like to see you push out to 5k.

 

[GSV]

I am not familiar with Mazda's oil recommendations for this engine but I tend to think that there is really no benefit in running such a thin oil for you.

I am leery of 20 weight oils unless the manufacturer specifically call for them. In this case the builder has to back the engine up if the 20 weight oil fails to protect the engine.

I'd say drain it after 1000 miles and consider it a flush.

Are you going to replace that turbo?

 

[Sin City]

Cujet, I would not feel safe using a 20 wt oil in a 1994 car. If this were a 2003 I might feel differently but I would not take a chance on an older vehicle. I look forward to seeing your UOA. If this were my car I would feel a lot safer using 5W-30.

 

[Cujet]

What does 1994 have to do with anything? The engine has EXACTLY the same clearances and oil pump as the new ones. If a new engine can use it, so can I.

If you are worried about existing wear in my engine, I am sure it has some. The car has about 35,000 track miles in addition to 60,000 street miles.

Still, this is not an exercise in engine longevity. I am interested in power. Any reasonable method may be tried. My experience is that the Miata engine is capable of high HP for extended periods as long as detonation is managed. I use about 20% toluene on a regular basis to eliminate knock and allow more boost.

So what if I have to overhaul it soon, it will just end up with tougher internal parts. Yes, I am going to re-install a turbo. I have not decided which type yet. I may go for the bigger power and install a T3/T4 hybrid. 400HP would be nice.

Check my car out at my homepage

Chris

[ July 21, 2003, 09:47 AM: Message edited by: Cujet ]

 

[TR3-2001SE]

I have a 2001 which is the same engine. The 2003 model with the same engine recomends a 20w oil. I used royal purple for awhile and it was as thin as 20w from the UOA of it. Never had any problems with it so I would say you are good with this oil. Mine consumes exactly 0 oil over 7500 mile changes so these engines are really tight as far as ring design I would guess. Just do a UOA and report back to us. Inquiring minds want to know.

 

[Cujet]

I have no issues with the oil. The fuel economy did not improve at all. The HP seems to be just a tick better if at all. Engine starts and feels warmed up right away. HLA pumpup is instant.

I broke a timing belt today. I pulled the valve cover and got a good look at the camshafts. What I found interesting is the lack of any detectable oil film on the lobes. As you probably know, there is plenty of oil in the camshaft area of the head as soon as the engine starts. Still, I wonder about the startup protection. Could be that the oil migrates to the HLA/cam interface surface and stays there, providing startup protection. I will look again tomorow.

Chris

 

[Sin City]

Cujet, yes I was referring to the wear that the motor would have and this having an effect on what motor oil viscosity would be safe to use in your car. Since money is no object than go ahead and use the 0W-20.

I put 5W-20 oil in my 1999 Mitsubishi Mirage when it had about 40,000 miles and was planning on doing a UOA on it but I gave that car to my mother and did an oil change just before I gave it to her since I din't know when I would see her next. I noticed that the car started much faster with Exxon Supeflo 5W-20 than it did with Mobil 1 10W-30 and the engine did not make any more noise with the thinner oil (5W-20). I could clearly feel the difference in performance when I was driving the car. The difference was not huge but I could clearly feel it. Unfortuantly I didn't bother to check my fuel economy with the 5W-20 oil before I gave the car away.

 

[Cujet]

Well, I figured I would give a quick update.

I left the oil in for 4720 miles due to being lazy.

I have taken a sample and am sending it off today.

The oil pressure was getting quite low, with 30PSI at 3500 RPM.

The engine is old with near 100K very hard miles on it. The power is not improved with the 0W-20. Actually the 10-30/15-50 blend I put back in makes more low end (probably due to ring sealing).

The high RPM (7000+) was just slightly better SOTP, however overall accel was unchanged. The fuel economy actually seemed to be worse, expecially towards the end.

Can's wait for the UOA results.

Chris

 

[Leo]

Did you have any UOAs before the current OCI? Should be interesting indeed.

 

[71dsp]

I just changed oil in our Miata last night (99 PEP), and I used 0W40 Mobil One with a Wix 51334 filter. In the past, I used 10W30 Mobil One with a Mobil One M1-104 filter.

I'm not sure if I'm noticing a difference because I want[\i] to, or if the difference is justified, but I had my wife take the car to work today to see if she notices a difference.

Anyway, the 99s don't have the HLAs, but the car did make a bit of noise at idle. After changing the oil, I had to run back up to the auto parts store to get some stuff, and I noticed that the ticking was either gone, or very greatly reduced. Even after I got back, and the engine was up to normal operating temp, no noticeable ticking.

I don't have an oil pressure gauge installed, so I can't say what the idle oil pressure is before and after the change. I've read that the Mobil One filters are quite restrictive, so I'm curious as to whether or not I'm running more pressure at idle with the Wix filter.

Anyway, so far I'm pleased with the 0W40. I put 5W40 in the Protege with a Wix 51344 filter. Maybe at the next oil change, I'll try 0W40 in it as well.

quote:

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Originally posted by cheetahdriver:
am currently using the 0w-40 in my miata, but the 0w-20 has been calling me. miatas love thinner oils on startup as they have a well diserved rep for HLA noise. since i switched to the 0w-xx oils (0w-30 to start with) this has been a non-issue. i have to agree with buster, this oil may be a winner with miatas. look forward to your analysis, and would like to see you push out to 5k.

---

 

[cvl]

Hey cujet, I can't believe that your Aerodyne lasted that long.

While the clearances on the 15 year old engine designs are the same from your 94 and the newer ones, the lifter design is not. Your engine will also likely need a bit thicker oil do to its mileage and FI history.

I really liked 300V and 8100 0w-40 when I had my turbocharged Miata.

 

[Mark in NY]

quote:

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Originally posted by Cujet:
I have no issues with the oil. The fuel economy did not improve at all. The HP seems to be just a tick better if at all. Engine starts and feels warmed up right away. HLA pumpup is instant.

I broke a timing belt today. I pulled the valve cover and got a good look at the camshafts. What I found interesting is the lack of any detectable oil film on the lobes. As you probably know, there is plenty of oil in the camshaft area of the head as soon as the engine starts. Still, I wonder about the startup protection. Could be that the oil migrates to the HLA/cam interface surface and stays there, providing startup protection. I will look again tomorow.

Chris

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Second point first. Welcome to dry camshafts!
Overnight oil drains off. All brands, types, viscosities. That is why a quickly circulating oil on start up is important to avoid wear. This is a combination of viscosity, oil system design and importantly- filter ADBV.

As far as MPG is concerned, my experience agrees with the theory which is - At light throttle the parasitic losses of the oil pump are a bigger percentage of the total engine output. At heavy throttle when an engine is producing over 50% of max output, the power consumed by the oil pump is inconsequential.
Translation - if I drive real easy for a tankful of gas I see 1-2 MPG increase with 5-20 vs 0-40.
If I drive in a more "spirited" manor, the MPG is the same no matter what oil is in the crankcase.

 

[MiataDon]

100,000 miles is nothing... I have over 220,000 miles on my 1990!

After I finish my Auto-RX cleaning and rinsing with dino Castrol GTX, I'll probably go back to using Mobil 1 10W30. Mobil 1 0W20 seems a bit thin to me. Good luck with whatever you decide to use.