Really Stupid Question

:mellow: Hmmm... Just an abstract question...

Why would someone WANT to switch back & forth from dino oil to synthetic?

 

<div class='quotetop'>QUOTE(Charles Suitt @ May 10 2006, 10:55 AM) [snapback]252800[/snapback]</div>

That is an excellent question. Synthetic oil is a pretty darn cheap preventative maintenance thing you can do for your car, to the point of being trivial compared to most expenses. And it does provide a tiny MPG improvement anyway.

In other words, is saving that $12 to $15 really worth it?

 

I can think of one reason. I have synthetic in now, but if I discovered a case of dino oil in my garage (which I had gotten for my last car), I would want to use it up.

 

<_< Howdy aaf709

That case of oil... does it "happen" to be the correct viscosity? Seems unwise to risk an engine if it's not the recommended viscosity.

 

<div class='quotetop'>QUOTE(Charles Suitt @ May 10 2006, 10:25 AM) [snapback]252881[/snapback]</div>

For the sake of this discussion, let's say yes. That would make it a valid reason to go back to dino (and then back to synthetic when the case is used up), although that wouldn't happen all the time.

In my case, I did find a case, but as my wife's car uses that same viscosity, I'll use it there. Good thing to remember, though. I also found a case of straight 30W, which I gave to my father to take to the local Aerospace Museum where he volunteers. Someone there might need it.

 

I've heard that you aren't supposed to use synthetic if you have a higher mileage car that has only used dyno. Synthetic is thinner and won't protect as well in a worn motor (save maybe for high-mile formulations). In other words if you switch to dyno for a significant amount of time you might not want to switch back to synthetic but if you've only use synthetic in the car theres nothing to worry about because there is no extra wear caused by and requiring the thicker dyno oil.

 

<div class='quotetop'>QUOTE(benighted @ May 10 2006, 12:40 PM) [snapback]252895[/snapback]</div>

It will actually protect just fine.

The problem with a well worn engine late in life that has never used synthetic is the seals aren't that good anymore. So the thinner oil will leak out. That's bad (obviously).

 

The 2004 manual advises against switching back and forth between fossil and synthetic but does not say why. Does the 2006 manual not give the same advice?

 

Here in Florida full syn. oil is the way to go. It does not attract or hold water like organic oil does. Also with the warmer temps much better engine protection with NO sludge build up. I have been using it in all gas engines (Harley,Truck,Lawn mower, since 1988 and have had 0 oil related trouble. Walmart has mobile 1 for under $20. for a 5qt. jug. And sometimes as low as $16. when they want a lost leader.