FYI on Synthetic Oil

Apparently, they were gathering information to determine if there would be an issue. Apparently, there is none.

So you're safe to try synthetic oil.

fJef

For many years auto makers have been leery about using synthetics. They have lagged the trucking industry, where you get longer warrantees for using synthetics. There is absolutely nothing to prevent you from switching back and forth between synthetic oils and regular oils. Toyota is simply a slow learner and paranoid.

Mike D.

Reputable oil makers, like Mobil, Castrol, Valvoline, and Pennzoil, have FAQs about at their websites about using synthetics in cars. I saw a very old one from Mobil that warned against using synthetic during the first 10,000 miles or in Mazda rotary engines or Subarus. I don't know about newer rotary engines, but I believe that the other restrictions were lifted long ago.

OTOH I wouldn't trust Amsoil for information because they claim that their oil improves fuel economy. But when I asked Mobil if their synthetic did the same, they emphatically said, "Not one bit."

I finally tried synthetic, not because it was better but because it was offered by Pennzoil and Pep Boys for 6 cents a quart, after rebates. I bought some more a few months ago because it was the cheapest oil available, 99 cents a quart, after rebate.

You think thats the reason? I am willing to bet it has alot more to do with preventing law suits and such.

Actually, all of today's oils are energy saving, compared with the oils of say the 70s and 80s. Mobil1 does claim better engine efficiency

I suspect that you would save 0.5% at most in fuel. That comes to a 0.15 mph increase in fuel economy in my car.

How did it work?

Jeff

There were two reasons why I was thinking about going with Mobil 1. The first reason was that the engines used in the Sienna had a tendency to develop sludge. While I feel this problem has been corrected, using synthetic oil would greatly reduce this possibility. The second reason is my oil change frequency. I drive about 10,000 miles a year, and change oil three times. With Mobil 1, I will feel safe in going to two changes, which is only 5,000 miles between changes. Charles Ranheim.

myoilchange frequency. I drive about 10,000 miles a year, and changeoil

I hear you~! My dealer here in Ontario recomends 5000 mile (8000k) oil changes using Mobil 1 grey cap(5W30)...`02 Camry-4 auto.

In the winter I use Mobil 1 yellow cap , the extended service oil(15,000 miles)It costs a little more than grey cap, but I think its worth it for winter driving.

However I change 2-3 times a year depending on mileage and type of service .

My driving is about 60 % city (severe service )and 40% highway (normal)

When you get right down to the nitty-gritty ? oil is the cheapest maintenance you can do.

I also use 15w50 in my bike, Mobil 1 mred

I haven't heard any knocking on start-up, and the engine hasn't smoked or blown up yet. :)

Ya know, I had to add some oil to my Mazda (conventional oil at last change) and all I had was a couple quarts of Syntec I use in the Scion.

Later I got to thinking: if they aren't 'interchangeable', then why are there synthetic blends on the market?

The generally accepted rules on synthetic oils are as follows:

1. Never mix synthetics. Different brands can use incompatible bases. (paraffin vs. PAO)
2. It's always okay to go from synthetics to conventional. (see number 4)
3. It's okay to mix synthetics and conventional if you have to. (see number 1) Try not to mix different conventionals.
4. You can go from conventional to synthetics, but the more mileage you have on your car, the greater the risk of developing synthetic "leaks". This is due to synthetics having an easier time of "finding" defects in seals, and is not the fault of your synthetic.

YMMV. I didn't write 'em, I'm just passing along conventional (no pun) wisdom. If you disagree, I'd like to know the reasons as these rules go back ten years or so. I was a victim of number 4 with the only Ford I've ever owned. It took about six months back on conventional for the leaks to stop. Caveat emptor.

I always use Castrol. Nothing else. So when I add Syntec to a conventional oil, I'm adding Castrol to Castrol.

Hopefully they made their Conventional compatible with their own synthetic!

Any modern synthetic is completely compatible with any other brand of conventional. Just don't mix brands. That's it, so you're fine.

I'd like to be able to answer that, but I've never used it. Logically it would be the same, but I'd need to read more about it.

please tell me WHY we cannot mix brands of oil?

We mix brands of gasoline with different additives or so I`m told ?,With no apparent harm to any gasoline driven engine, so why not oils ? just curious

Different synthetic oils use different types of molecules for the oil bases. So it is not a good idea ot mix them.

mred opin'd thus:

No one can tell you why; it's just "generally accepted", that's all.

(Another way of saying it's a myth.)

Modern oils, if they have the SAE seal, are all miscible.

-Don

You can mix synthetics with any brand of conventional. You cannot mix different brands of synthetics as you don't know if they're paraffin or PAO- based. I'm no chemist, but apparently bad things happen.

You probably can mix different brands of conventional, but to be cautious should not. All oils have an additive package. Some may or may not be compatible with others.

That's it, in a nutshell. As I said earlier, YMMV. I didn't write the stuff, just did a lot of reading.

They may all be miscible, but they're not mixable. PAO and paraffin-based synthetics are not compatible.

Live with it.