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0w20 vs 5w30 Oil Results - Accord 2.0T

1153 Views 4 Replies 3 Participants Last post by  EngTech1
So I decided to do the testing on my own car and collect the data from oil lab testing.
Results attached bellow.
2000 miles on the 0w20
4000 miles on 5w30

This was done between November 15 through march 15. Still in the low morning temps, around 30-40F with daily highs averaging around 50F sometimes hitting 60-65F.

Mods: None except K tuner stage 2

Driving habits: Start up in eco mode (factory boost) and warm up, drive first 15 minutes in eco for warm up, 85% highway miles.

As you can see, firstly, 0w20 doesn't create a good enough seal in the cylinder, blow by is pretty bad, pushing fuel dilution to 1.8% in just 2000 miles. Imagine if I drove 4000 or even 10,000 miles like many recommend. Fuel dilution would have been pretty bad. This is on a practically brand new engine using honda's own oil. All the honda owners manual stans need to wake up.

Switched to my preferred oil 5w30 Valvoline. Mostly because I can get it for like 26$ for 5qts and I always run the high mileage version full synthetic. As you can see from the results, firstly there is nearly no fuel dilution. Biggest issue now is viscosity degradation. 100 degree cSt when the oil is new should be around 10.7 according to SAE tests and valvolines own documentation, yet over 4000 miles it fell down to 8.3. That is a 22% reduction in viscosity. Although oil rarely will reach 100C in the oil pan, it will exceed that in the turbo charger.

Over all, might switch to a higher strength 5w30 if I can find a steady supply of it under 30$ for 5qts in my area. But just based off this data, switching to a 5w30 oil is already MUCH better. Honda's 0w20 is obviously trash, doing pretty much nothing to really protect the engine, flash point is so low that its lower than what I would get with 0w16 on my toyota's, and the fuel dilution even on the k20 is a problem people keep denying yet I have evidence.

Either way, Just wanted to put that out there.
The data is all here, trolls be gone, I won't respond or participate in arguments of which oil is better or which brand or how none of this matters because engines are "so high tech and engineering is so good" etc. Engineering is always limited by the finance department, source, I am an engineer.


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Absolutely Nothing Wrong with 5W20 . .

Not so sure on the 30W as that's Pushing thee Clearances on New Motors - like Cam Bearings
Turbo Bearings , now If My Motor had 100K or more - then Go wit that ..

If Your Really have an Oil Dilution Issue - the Try a Marine = Boat Oil for 4 strokes
That will make a World of Differences - same goes for ~ 1.5Turbo's
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