re: Is synthetic oil a waste?

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ol wut?

i get $19 oil change specials in the mail from the local toyota dealer here like every other month.

not worth my time doing it myself for $20.

people who go to jiffy lube are the suckers.

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I get those 2 from my dealership and other companies but they ALWAYS end up charging more than $20. They will tell you its only good for a certain type of oil, your car needs more oil than is provided in the deal etc.

compare an oil change for a car on conventional at 3k and another car on synthetic at 5k. Use the same filter.


you'll see the difference in oil change. one comes out smooth still while the other comes out thick and globular.

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I use amsoil full synthetic and change my oil every 20k miles or so. The extra you spend on the synthetic oil is more than justified by not changing your oil every 3k miles....plus I have seen about a 10% fuel mileage increase. My car was seeing 27 or 28 mpg on the highway, now it's right at 31mpg. I was skeptical the first time I used it, but it's definitely not a waste.

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Same here....it costs me about $60 a year.

Back when I used to piss money away modding my LS1's, I sent off oil for analysis a few times and was shocked at how well Royal Purple and Mobile One were holding up after 10-12k miles.

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I suspect the manufacturers are now recommending it because it makes their EPA ratings look better

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I doubt this is why they may recommend it; a better bet would be that they could charge you more.

I've heard this debate a lot. It's probably true if you change your oil every 3k -5k on the dot.

Personally, I use synthetic and change the oil myself at 5-6k miles. I don't mind paying the extra $20ish for peace of mind.

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than a thinner, synthetic oil.

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This is old wives tale that came out about same time as Mobil 1 was placed on the market site. Synthetic is no thinner than dino. They have to pass the same test.

You want an answer to your question? Never ask a mechanic. They turn wrenches but don't know jack about fluids.

I wrote an article a few years ago on this. I consulted with a Tribologist. Bottom line is miles between oil changes and driving conditions. Do the math according to your own costs.

Here is a good place to start if you want a complete answer.
oil education

I use oil that has less numbers between the number before the W and after the W. Example: I prefer 10W30 over 5W30. Why? The additives used to get these numbers shear as the miles go up. After a few miles the 5W30 tends to act more like a 18 weight vs 10W30 which acts more like a straight 20 W. Here in south La. we can get away with using 10Ws vs 5Ws.

The 10W will stay closer to actual 10W30 longer too. It takes less additive to get that formulation.

Have to make sure your motor will work properly with different weights as well. My truck has cylinder deactivation (hemi V8s and most GM V8s have it) so you should run what the manufacturer recommends...or search the forums to see if anyone has changed weights without issue.

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Have to make sure your motor will work properly with different weights as well.

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Another good point. Certain engines have special requirements. Turbo charged engines are getting popular. Their requirements are very stringent as well. Staying with what your manufacturer says is the way to go if you don't know very much about oil.

I play around with this a lot. I never deviate very far from what the book suggestion. We have everything from lawnmowers to V8s producing 1000h.p. We haven't had a single engine failure due to oil yet.

"We" is myself and my sons (car enthusiasts and one is a M.E. specializing in rotating equipment.

Wait, so you are saying that eventually it is the same viscosity at 0° as it is at 205°?