Piston Slap: Synthetic to Dino Switcheroo Edition
TTAC commentator Geo. Levecque writes:
Hello Sajeev, greetings from Canada. If you switch Oil to Synthetic, can you go back to the old stuff? If it matters, I am asking about my 2008 Toyota RAV4 2008, 4 Cyl, with 18,000 kms on it.
Sajeev replies:
Your engine is a baby. Not because it’s small and lives in a cute-ute, but because your new-ish Toyota isn’t set in its own way. Parts in your engine don’t yet move to their own (microscopic) groove. As engines get older and tolerances change, switching between synthetic and dino oils makes your motor fight its natural, programmed movements. For now, this isn’t a big deal.
So you can, but after your motor clocks 100,000+ kms, you run the risk of upsetting the delicate balance that synthetic oil worked hard to create. I personally don’t think it’s a wise idea. And won’t recommend it.
Bonus! A Piston Slap Nugget of Wisdom:
Walk into any parts store and you’ll see specific oils made for high mileage vehicles. You are usually asked (by their accounting department) to switch to these oils after 75k (miles) for longer life. These oils have extra additives to help older engines reduce oil consumption, plug leaks or make a host of funny noises (like timing chain rattle or main bearing grumbles) go away. Which is nice, in theory.
In reality, an engine with 75k isn’t much different than one with 10k. Modern engines easily run past 150k with little or no change in performance. So change your oil regularly, use a good filter and stick with your regiment for the rest of your (car’s) life. That is the only way to fly.
[Send your technical queries to mehta@ttac.com]
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I find Piston Slap posts to be a great starter for interesting discussions regarding various automotive issues that aren't covered elsewhere on this site....and I'm sure the majority of TTACers agree on this. The time you told the Ford Truck guy who’s truck wouldn’t turn over to check his battery cables… So CamaroKid, are you finding fault with his suggestion that the battery cables on an old truck could be suspect? Seriously? That's your beef? Of course there are multiple possibilities for a no start condition, but since you are trying so hard to critique this column, I suggest you try harder.
I agree that discussion is great... And the Ford truck one, was, as I said, the first time I thought, "Wow! how could he miss something that simple, that mechanic needs to take a few more courses..." Of course the third or four guy told the person posing the question what to fix... But, since then, he has basically proven to me, and yes, unlike P-Slap I have my ASE certification, that he is just throwing stuff out there to start a discussion... If that's what you hope for, great, but if you are looking for expert advice, you are barking up the wrong tree. Lets be honest here it is next to impossible to diagnose a car without ever seeing it, and being an expert on every make and model ever made is even harder. So what is my beef? It is simply that someone might actually think they are going to get expert advice. With a name like "TTAC", if you have someone billing themselves as the "self help car guy" you would hope that he has even the most basic qualifications. I kinda take the "Truth" part seriously. So this month we have the BS answer that we can't switch between synthetic oil and old school stuff because it will upset the "delicate balance that the synthetic oil worked hard to create." WOW! Now both eyebrows are up.