# 18 CRV CVT with TAN 50% new fluid

#### himemsys

CVT fluid capacity is 8 qts. First sample is with the factory fluid at 24.7k miles. At that time I drained 4 qts and replaced with new Honda HCF-2. So this sample has 3.9k miles since the last sample. 50% of the fluid has 3.9k, 50% has 28.6k. Wear metals are nearly half and TAN dropped as well. Virgin TAN is 0.4, so the 0.9 TAN now is excellent. It shows that replacing just half of the fluid makes a significant difference. I'll do another 4qt drain and fill in about another 5k and we'll see what those results look like. I'm guessing once that's done, I'll be set for another 15k or so before I start the whole thing over.

I'd probably do a drain and fill every 20-30k since you are doing it so early while its still in relatively good shape.

What you are doing is quite aggressive service schedule.
Nothing wrong with that. might be wasting a few bucks but hey I spent 11bucks at starbucks yesterday.

I will be doing this on the 2020 elantra soon. after it hits 30k it will get a drain and fill at back to back oil changes.. then good till 60k

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Thought: since 50% of the fluid is new and 50% is original, to get adjusted wear metal values, we can divide the original wear metals in half, then assume the difference is what accumulated in 3892 miles.
Al: 7 - (11 / 2) = 1.5
Ch: 0
Fe: 24 - (43 / 2) = 2.5
Cu: 5 - (9 / 2) = 0.5

So in 3.9k miles the CVT fluid accumulated 1.5ppm Al, 2.5ppm Fe, and 0.5ppm Cu.

Thought: since 50% of the fluid is new and 50% is original, to get adjusted wear metal values, we can divide the original wear metals in half, then assume the difference is what accumulated in 3892 miles.
Al: 7 - (11 / 2) = 1.5
Ch: 0
Fe: 24 - (43 / 2) = 2.5
Cu: 5 - (9 / 2) = 0.5

So in 3.9k miles the CVT fluid accumulated 1.5ppm Al, 2.5ppm Fe, and 0.5ppm Cu.
Adjusted wear values? So you're making comparative wear determinations in a mixed oil buy using a \$30 spectrographic analysis of the mixture?

Forgetting for a moment that's not a valid analytical tool for full oil changes, it's really out of bounds for a mixed oil fill.

LOL.

I'm not submitting an official document, just giving myself a ballpark estimate of how much wear metal accumulation has occurred in the last 3900 miles.

Remember, this is kind of a special case: Original factory fill is a known. Half of it drained out is a known. Half of it replaced with identical virgin fluid is known. The rest is math.

LOL.

I'm not submitting an official document, just giving myself a ballpark estimate of how much wear metal accumulation has occurred in the last 3900 miles.

Remember, this is kind of a special case: Original factory fill is a known. Half of it drained out is a known. Half of it replaced with identical virgin fluid is known. The rest is math.
The LOL belongs on the conclusion drawn from that UOA. The bolded part only makes it worse.

The LOL belongs on the conclusion drawn from that UOA. The bolded part only makes it worse.

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