Synthetic Oil

For viscosity, check your owner's manual. It is the same viscosity that you would use with conventional oil.

For brand, I like Mobil 1. Valvolene, Chevron, Shell, Pennzoil and others sell synthetic oil. As long as it is a name brand whose conventional oil you trust, it should be fine.

Jeff

Since you are switching to synthetic after some engine wear using conventional oil, you might consider 10W-30. But I would start off with

5W-30 and see if that causes any abnormal oil consumption, and stay with that if it does not.

I prefer Mobil 1, but any major brand is OK.

But he really doesn't need to switch to synthetic only because of

*fear* of sludge. IIRC, a 2004 Avalon is not prone to sludge

Just curious, why are you suddenly afraid of your oil sludging up? Have you had problems with that car? The car is three, almost 4 years old and if it hasn't had any problems related to oil sludge, then why spend the extra money on synthetic oil? Use that money to buy gas!

Jack

Actually, synthetic oil does not necessarily cost more, especially if you are used to changing conventional oil at about 3000 miles. Switch to synthetic and change every 5000 to 6000 miles.

Also, you will get about 1% better fuel economy, and if you keep receipts, you car may have a higher resale value. (not to mention a lower chance of other engine problems caused by excessive wear).

If you are using the same viscosity oil with a similar additive package, there is no reason to expect synthetic oil to provide better fuel economy. For three different vehicles I have compared the fuel economy using synthetic oil to the fuel economy using conventional oil (good quality conventional oil) and have never detected any measurable improvement.

The test to qualify for the Energy Conserving II designation involves comparing the oil under test to a reference PAO synthetic oil of the same viscosity. To get the rating, the oil under test must get better fuel economy than the reference PAO synthetic oil. It is the additives that improve the mileage, not the type of oil, assuming the same viscosity. There are two reasons why synthetic oil might provide slightly better fuel economy - superior cold weather performance under extreme conditions and better stability over long periods, assuming the oil is not changed regularly. It is unlikely that you would be able to measure these changes unless you take them to extremes.

Among synthetic oil marketers, Amsoil goes about as far on the limb as anyone in climing an improvement in fuel economy. THey say:

"Maximizes Fuel Economy

"AMSOIL Synthetic 5W-30 Motor Oil is designed to maximize energy efficiency for improved fuel economy. Unlike conventional oils, its uniform molecular structure helps it flow more freely and reduce friction between metal surfaces. Anti-friction additives are included to further improve energy efficiency."

The first part of the sttement is pure marketing BS. Viscosity is a measurement of how freely an oil flows, so conventional and synthetic oils of the same viscosity will have similar abilities to flow freely and reduce friction. The second part of the statement is the meant - "Anti-friction additives are included to further improve energy efficiency." This is what provides improvements in economy. Of course sionce additive packages are not unique to synthetic oil, Amsoil is not likely to emphasize this.

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Ed

In comparison, Exxon-Mobil's consumer hotline, 1-800-ASK-MOBIL, when asked if their Mobil 1 oil improves fuel economy, answered, "Not one bit."

They don't want to get into trouble with the FTC and the lawyers have told to marketing people to categorically deny it. People love to sue big companies such as Exxon/Mobil.

A 1% increase in fuel economy is not much, but the cost of synthetic oil changes is not much either.

I stand by my claim of 1% better fuel mileage. I also stand by my claim that synthetic oil will more than pay for itself over the life of the car, unless perhaps one has a 2-3 year lease and don't plan on keeping the car after the lease expires.

2004 runs at a higher temperature. It's after the Low Emissions Vehicle (LEV) rating started in 1997. You may still be fine on dino like myself every 3000 miles using Purolator PureOne or Bosch Filtech filters. No cheap Toyota filters shipped all the way from Thiland for me. I'd recommend the thickest viscosity approved for the temperature range.

Either the Group III hydrocracked (OK) or the Group V synthetic esters (better) should work very well compared to dino. Newer European standards spec only Group V oils if you insist (BMW LL04?). For reference, google the BMW LL01/LL04 standards or VW 502/503/505 standards.

But never go longer than 5000 miles -- in 2004 Toyota reduced the interval from 7500 down to 5000 at least for post 1997 LEV engines because of sludge concerns. So going above 5000 in affected engines essentially voids the warranty.

A 1% difference in fuel economy in real life driving is statistically meaningless for today's synthetic and conventional oils, especially when the driver knows what type of oil is in the engine, and even a

10% difference may be insignificant. And for your contention that large oil companies don't want to deal with the FTC is also not credible since Exxon and ARCO made claims of 4-5% improvement back in the 1970s, when fuel-conserving oils were just starting to be sold for cars and when the FTC was much more active in protecting consumers.

Statistically insignificant? Yeah, the difference in the price of conventional oil vs. synthetic oil is statistically insignificant in context with the total purchase price and operating costs of a car over its lifetime. In fact, if you consider salvage value (the value of a car when it is sold) into the financial analysis (which any competent financial analyst would), synthetic oil is often cheaper.

It wasn't Exxon and ARCO that made these claims, they were just quoting the API. The API still classifies some oils as being an "energy conserving formula" compared to other oils. Mobil 1 web site mentions which of their oils carry the "energy conserving formula" API designation.

jor

I wasn't including the costs of oil, and neither were you when you made your fuel economy claim.

No, they were claims made by Exxon, for its Uniflo oil with moly additive, and ARCO, for its ARCOgraphite. ARCO said it took some miles before the fuel economy increased.

I have been using various brands of synthetic oil, Quaker State and Mobil in my Corolla. After a bit of research I found that fuel economy gained is negligible. Where the real savings can be found is in the reduced engine wear, especially in cold weather starts. In sub zero weather your engine will start more easily due to less friction, putting less demand on other components like your starter and battery. The oil viscosity should be kept as per manufacturer specs. Regular motor oil looses it's viscosity in cold weather where synthetic oil remains fluid to much colder temperatures. If you plan on keeping your car longer than your usual lease agreement, then yes, synthetic oil will save you money in the long run.

The cost of synthetic oil can be minimized by hunting for sales between oil changes. When you find a good deal, buy a few jugs and then supply your own oil when you bring your vehicle in for service. Make sure that you ask to have any oil left over to be returned to you, so you can top up if you need to afterwards. It's not a good idea to mix different brands of synthetic oil.

As for your fear of slugging and changing over to synthetic oil as a preventative measure, you could try a synthetic blend that is less expensive.

The key is to change your oil on a regular basis,

I think there is some confusion here. Someone claimed that the extra cost of synthetic oil is not worth it, and I disagreed saying that the cost was offset by better fuel mileage, better resale value, and fewer repairs costs. The price difference of synthetic oil over conventional is not much, so it doesn't take much fuel savings to at least partially offset that cost.

You said that fuel savings are statistically insignificant over the life of a car (I think that is what you meant) and I agree. But the extra cost of synthetic oil is also statistically insignificant over the life of a car.

If I misstated your position, please correct me.

The extra cost of synthetic oil is also negligible as well.

Let's say (just for the sake of argument) that one drives 15K miles in a year and gets 25 miles per gallon (fairly generous for a Camry). At $3.00 per gallon, a 1% fuel savings would be $18 per year savings. That would offset the cost of a synthetic oil change for at least one oil change.

If the car is not under manufacturer warranty anymore, or only specifies an oil change every 7500 miles, you only need 2 oil changes per year with a synthetic oil if driven 15K miles per year. And if there are people who change their oil every 3K miles with conventional oil (I am sure some do), then switching to full synthetic at 5K miles would make the cost of synthetic just about even with conventional oil.

Yes, I agree.

Just to put this in context, a 1% increase in fuel mileage would be 25.25 miles per gallon compared to 25.00 miles per gallon. A small difference, but $18 per year if you drive 15K miles (assume gas is $3.00 per gallon).

Personally (although I don't want to try and defend this in court), I think synthetic would improve fuel efficiency by about 2%.

1% better fuel economy, oh my! That explains it, I could save $0.03 on every gallon of fuel I use.

I pay 2 to 3 times the cost of conventional motor oil, change oil at about 25% to 30% longer intervals. Yep, I'm going to save a bunch.

If all things were equal, would YOU pay more for a car who's owner used synthetic oil but didn't change the oil at the manufacture's recomended intervals?

Jack

I don't think you could show even a 0.1% improvement if the conventional and synthetic oils had the same additive package. It is the aditives that have the biggestest effect on fuel economy, not whether it is synthetic or conventional (assuming the same viscosity). When Ford switched to 5W20 oil, they claimed it would only provide something like a 0.6% improvement (comoared to 5W30).

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- the base line test oil is a full synthetic oil. In order to get the energy conserving rating, a 5W30 oil, conventional or synthetic, must provide better fuel economy than the reference synthetic oil. Ed