Has anyone used 0/5W20 in an old engine?

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Let's hope this thread doesn't turn into a thick vs thin war.

I was wondering if someone here ever used a 5W20 or 0W20 in the long run in an older engine (say from the 90's) for which a 30 or 40 grade oil is specified. I'd like to hear from those who tried it.

Let's take engines i have experience with as examples : Mercedes M111 engine, 4 cylinders, DOHC, duplex roller timing chain. Or the M112 engine : V6, OHC, 18v, duplex roller timing chain. What it so different in these engines from other similar engines from a japanese or american manufacturer that spec a xW20 oil? They're quite basic engines. Does they need a 3.5+ HTHS or is it just because of ACEA and their hard-on for high HTHS dual rated oils?

I don't plan on running such oil in my cars but i've not seen much about running a 20 grade oil in an old engine, especially in a MB, BMW or VAG engine and i'm curious. To my knowledge, user HTSS_TR did run M1 0W20 for many years in his E430 with a M113 engine but that's all i've seen.
 
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One of the secrets to fast lap times in Daytona, during the 1980's used to be to switch from 20W-50 to 5W-30 synthetic or thinner if they could find it. In college at ERAU/Daytona, I was a regular at the track and watched one famous team fill yellow bottles from silver bottles :)

With that high RPM advantage in mind, I put 5W-20 in my Turbo miata in an attempt at getting more high RPM HP out of the little 1.8L engine. I removed the turbo for it's overhaul and drove it like that for a while. Imagine my surprise on my UOA when I saw over 220PPM Pb, along with far higher levels of Fe and Al. Of course, the car had an aftermarket ECU and redline was 8400 or 8600 depending on my mood.

The bottom line was that Mobil 1, 5W-20 was insufficient for such high RPM use, and resulted in an engine teardown, mostly based on the bad UOA. What I found was interesting. There was no disaster inside, only some obvious, but relatively minor rod bearing wear. I'm not saying it did not need to be freshened up, it did. But it was not a blown engine or catastrophic failure.

Had the redline been kept to the OEM 7000 RPM, there would have been no visible issues what so ever. The overhauled engine was fed Mobil 1, 15W-50, ran 33 pounds of boost, and lasted for years of daily driving and track days, including some days at Homestead. Never another bad UOA. 8600RPM was the norm.
 
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Yeah I put some 5w20 in my beat to heck 1994 dakota 3.9 because I got it on sale. Forget my reasoning, maybe figured it was winter and I was only driving a 6 mile round trip drive to the dump. Anyway the oil light came on at low idle, so that ain't good.




I also used it in an 05 prius (manual specs 5w30) with 250k+ miles and had no issues at all. Toyota back-specced it for that motor.
 
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Didn't Gokhan use it in an older vehicle?

I was right, here is the thread: https://bobistheoilguy.com/forums/threads/thin-or-thick-tgmo-0w-20-m1-0w-40-final-verdict.269010/
Yes, I have run SAE 0W-20 in my 1985 Toyota Corolla LE for a long time with no problems until it got totaled by a hit-and-run driver. The 4A engine was capable of doing over 150 hp with DOHC and fuel injection, and my carbureted SOHC 4A-LC version version had perhaps 74 hp tops. Since 10W-30 was recommended for the fuel-injected DOHC, the carbureted SOHC could easily go with 0W-20 if not 0W-16. Bottom of the line: Most engines are designed highly tolerant to oil viscosity.

There is one caveat: I wouldn't be able to run 0W-20 or 5W-20, in fact not even 10W-30, if I didn't replace my valve-stem oil seals, as worn-out valve-stem oil seals require 15W-40 to control oil consumption.
 
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Yeah I put some 5w20 in my beat to heck 1994 dakota 3.9 because I got it on sale. Forget my reasoning, maybe figured it was winter and I was only driving a 6 mile round trip drive to the dump. Anyway the oil light came on at low idle, so that ain't good.




I also used it in an 05 prius (manual specs 5w30) with 250k+ miles and had no issues at all. Toyota back-specced it for that motor.

280 rpm at idle?? I wouldn't be surprised if the low oil pressure lamp lighted with SAE 60.
 
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Put 0w20 in my old Honda that required 5w30...burned around a quart every 500 miles. Now, that car had high mileage, so perhaps that’s why it burned so much? And quite honestly I never switched back to 5w30 because I sold the car (289,000 miles).
 
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Yeah, my dad has ran 5w20 exclusively in his mk3 jetta until it flipped in 2013 , ran great, had good compression, didn't burn oil, but had a really bad leak on the main crankshaft seal considering it had over 431,000 miles If i remember correctly.

My Honda odyssey has only ran 5w20 , it never exceeds 2,000 rpm though. Going to use 5w30 from glitch week, but thats going to take at least 2 years until I change the oil.

I would consider using an oil from what it sees.
 
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That's a great question!

I recommend searching for posts/testing by member Gary Allan. Gary used a custom 0W10 blend in his TJ Wrangler's 2.5L four cylinder (tractor engine compared to todays engines) and had some surprising UOA's and data.

Unfortunately, Gary passed away ten years ago this year. I actually think about him every now and then when I change the oil in my trail Jeep pictured on the left.

As far as personal use goes, I rolled over one time and was in a weird spot where it took a couple of rigs a bit of time to right me up. I lost most of my oil out of the pcv intake (don't worry, my club carries a certified cleanup kit). Long story short, I was able to scrounge enough spare 5W20 from my F-150 tow rig and and another Ford to keep wheeling the weekend. Oil pressure was normal and I don't recall any odd noises beyond the rock scrapes on the axles and belly.
 

JC1

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I just added a frankenbrew of VWB 5w-30 with 50 pct Valvoline synpower 5w-20 in my 97 civic. With the current state of things we are driving leas and doing many more short trips. I'll probably change the oil to full synthetic around The end of December for Jan-Feb when it gets really cold here.
 
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I ran a 3000 mile stint in my 91 Miata with a 0W20, which included a track day and a couple of autocrosses. Motor ran the same as it always did. Pressures were just fine. I can't remember exactly which one it was, but it was some form of Mobil product. I'm thinking it was their entry-level synthetic. Supersyn? Something like that.
 
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