Which Amsoil Synthetic is Best

[Davo53209]

Hey everyone:

I've just recently purchased a 2004 Toyotal Corolla LE, that has 91,453 miles on it, whereas natuarally, I would like to squeeze as much fuel economy out of it has possible. It presently needs an oil change, so I thought, what better place to start.

Occassionally, I've come across several threads on this site that seem to advocate the use of Amsoil synthetic, yet there are a dizzing array of choices, along with some concerns which need to be addressed.

First off, I've got the guys at Autozone telling me that I don't want to run straight synthetic in a car that has over 50,000 miles on it. They're recommendation is to use a blend of conventional oil, mixed with a synthetitc to prevent the detergents from clearing away the false seals, which may have developed in the engine over time. Secondly, would Amsoil Ow30 be too thin, whereby causing future problems, or would it be safer to run 5w30 or 10w30. Thank you all.

[GasSavers_Erik]

Running synthetic in a car with that many miles may lead to more leaking.

The car manufacturer should have specified the viscosity range for the temperature you plan on operating it at.

IMHO- I would not want to go lower on the second number (hot viscosity) than the manufacturer recommends, but you would probably be OK going lower on the cold rating. EX. If manufacturer recommended 10w-30 for teh temp you plan on driving, you could likely go with 5w-30 but 5w-20 might be pushing it.

[theholycow]

If a 2004 with 91,453 miles has false seals then Toyota is by far the worst manufacturer in the world. That's a young car and should have absolutely nothing wrong inside the engine. Anyway the thing about not switching to synthetic is a myth.

If you're trying to save money by saving fuel, keep in mind you'll have to embrace Amsoil's 35,000 mile oil change interval just to make the $10/quart oil affordable.

IMO, if you'd like to switch to synthetic then use a reasonably priced store-bought brand. I don't think it's going to save a measurable amount of fuel either way but it's worth a try if you want to.

If you really want to save fuel then try a lighter weight oil, if your car recommends a variety of weights. Speaking of weight, you probably should NOT put 10W30 in your 2004 model which probably was designed for 5W30...wouldn't want oil to flow too slowly when cold.

[bowtieguy]

Amsoil's "Signature Series" 0W30 is considered by some(many?) to be the best motor lubricant in the world. and yes it ain't cheap. no it's not too thin.

[kamesama980]

first problem: you asked the guy at autozone. I know one guy i'd trust at autozone and I know him from school. I've yet to meet someone in autozone that's actually qualified to talk about cars.

I started running mobil 1 5w30 in my moms 02 buick with 100k miles and it doesn't lose a drop between oil changes.

The problem with suddenly switching to synthetic is that IF sludge and crud are blocking the leaks and holding the oil in, the synthetic will loosen it and unplug the leaks.

[bowtieguy]

Originally Posted by kamesama980

The problem with suddenly switching to synthetic is that IF sludge and crud are blocking the leaks and holding the oil in, the synthetic will loosen it and unplug the leaks.

correct! i also understand that a well maintained vehicle on conventional oil that has developed leaky seals, MAY have those seals reconditioned by synthetic such that the leak is lessened or stopped completely.

[theholycow]

Originally Posted by bowtieguy

correct! i also understand that a well maintained vehicle on conventional oil that has developed leaky seals, MAY have those seals reconditioned by synthetic such that the leak is lessened or stopped completely.

There's also the issue that a 2004 model with 91,453 miles should really, really not have any leaks or seal problems regardless of what oil was previously used.

[Davo53209]

Okay, so it would seem that the general consensus is that it would be safe to run full synthetic in my car. Additonally, I do have to mention that I've discovered that the previous ower did use a synthetic blend from their last oil change, as indicated by the sticker in the top left hand corner of the windshield.

[Davo53209]

As far as the weight, how safe does everyone think that it would be to use Amsoil Ow30 for all year driving?

[GasSavers_Erik]

Yes- it will be safe to switch to synthetic.

What weight does the manufacturer recommend?