I have a 2008 Honda Fit GD1 that has around 115.000 kms or 70.000+ miles on it.

For what is in the hood sticker, its been using Lubrax (a Brazilian brand) in the mineral form. I have the service book and it always was serviced in a official Honda dealer, so I don't really know if the put Lubrax in it or Honda's oil.

Anyway, I was thinking of switching to Honda's syntethic oil and I dont know if it will produce leaks. The car has 0 leaks at this time.

As far as I've been told by the Honda dealer they are using 0w20 in all cars and 5w30 (synthetic) for 6 cylinder engines.

Can I go ahead and put this type of oil?

If it leaks, can I just flush it and change it back to a mineral oil with the same weight?

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  • There's a comment in that post that says that this question sometimes is particular for a make/model/year, so i though of asking a similar question but with my particular car. The manual states that i can switch to a synthetic oil of the same weight. – Jh62 Nov 8 '17 at 22:29
  • @Pᴀᴜʟsᴛᴇʀ2 I don't think it's a duplicate. That question asks about the benefit of switching, this question asks about causing leaks because of switching. – tlhIngan Nov 8 '17 at 22:50

There's 2 parts to your question:

  1. Can I switch to synthetic oil. Yes you can and you totally should. When I started doing my own oil changes 8 years ago, I switched all 4 vehicles to synthetic oil. All of them are double or triple the age of your Fit, and all have double or triple your mileage. Two of them started leaking a little bit, but it's manageable.

Here's what happens when you put synthetic oil in an engine that's had mineral oil in it. Mineral oil has less ability to keep particulates in suspension, so it will allow particulates to settle in corners and on rough edges. This usually helps seals and gasket that are cracked or leaking to remain sealed.

Synthetic oil has a much greater ability to keep particulates in suspension, so during your first synthetic oil change, the oil will be very dirty because it will pick up all these little particulates that have deposited for years because mineral oil was unable to keep them in suspension. This will keep your engine cleaner, but it may reveal some leaking seals that were previously patched by deposits. You should deal with those leaks, but they are likely to be manageable until you actually have a reason to get to those seals and gaskets.

In addition to this, synthetic is way better for your engine. One of my cars was unable to start if it sat overnight at -10C or colder without using an electric block heater, but since I switched to synthetic, it always starts fine, even as low as -30C.

  1. Should you switch back to mineral oil if there are leaks. If you get leaks, the synthetic oil isn't leaking out directly because of a magical property of it, it's really a seal or gasket that is not providing a 100% seal. Switching back to mineral oil will not stop the leaks, you will just be leaking a less expensive type of oil.
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  • Those are excelent arguments. Thanks. But what if I just stick with the same oil and forget about all this leak problems? Maybe i should have thought of asking this before buying 4 lts of synthetic oil. – Jh62 Nov 9 '17 at 0:38
  • @Jh62 If you car is running fine on mineral oil, it will keep running fine on mineral oil. I'm sure you can find somebody who would gladly buy that unopened jug of synthetic oil form you for a slight discount. – tlhIngan Nov 9 '17 at 5:05
  • @jh62, first of all there are various properties to synthetic oil. I don't know what you picked up. And it's unlikely it'll leak at this mileage. – Numair Aidroos Nov 22 '17 at 1:14

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