Motor Oil - Synthetic vs. Conventional

toyota
engines
oil
corolla

#1

I recently bought a 2010 Toyota Corolla. The saleswoman said that the car had synthetic motor oil in it (and allowed longer oil-change intervals). She also said that I had to use synthetic.



However, in the owner’s manual, no reference at all is made to synthetic motor oil, only to grade and spec (ILSAC).



So, my question: Does the oil being synthetic matter in terms of operation and the synthetic just buys a longer change interval, or does the synthetic actually work differently?


#2

You can use any oil you want if Toyota does not specify synthetic. Just make sure it is the proper blend. You can extend oil change interval with synthetic oil in it has extra additives. Mobil1 Extended Performance does use extra additives. I would just use regular old mineral oil of the correct grade and change it whenever the manufacturer recommends to. It doesn’t hurt the car to change more often, but it does hurt your pocketbook.


#3

My 2011 Toyota Sienna calls for synthetic 0W-20 oil. The manual called for an oil change at 5000 miles, but a letter from Toyota extended the interval to 10,000 miles. I don’t know whether or not this applies to the 2010 Toyota Corolla.
I grew up believing Tom McCahill who stated that multi-viscosity 10W-30 was “a lousy number 10 and a lousy number 30 weight oil”. He thought the only reason for 10W-30 was so that service stations didn’t have to stock as many different weight oils on the shelves. I also changed oil every 1500-2000 miles in those days. When I bought a Rambler in 1965, the owner’s manual required 10W-30 and specified an oil change every 4000 miles. I drove the car well over 100,000 miles without any major engine work and the car was running well when I sold it. However, I drove the Rambler in constant fear that the engine would blow because I followed the manual and didn’t use straight weight oil as Tom McCahill recommended.


#4
You will likely find any oil that meets the specifications will be a synthetic.  Most all cars require a synthetic.  It allows them to recommend longer oil changes and can even give you a tinny mileage increase.

#5

I grew up believing Tom McCahill who stated that multi-viscosity 10W-30 was “a lousy number 10 and a lousy number 30 weight oil”. He thought the only reason for 10W-30 was so that service stations didn’t have to stock as many different weight oils on the shelves.

Please note that Tom died in 1975, and probably quit writing for Mechanix Illustrated (to which I also subscribed) sometime before that. Oils have gotten a lot better since then. IMHO that is one BIG reason why we see more and more 200K and even 300K mile engines these days.

Motor oils that meet the current API SM rating may also meet the new International Lubricant Standardization and Approval Committee (ILSAC) “GF-4” and “GF-5” specifications, which some European and Asian auto makers require.

There are both dino juice and synthetic oils that meet the new specification. Personally I’d stay with the synthetic. It won’t hurt anything, and you should be able to go at least twice as far between oil changes as you can with “old fashioned” oil.


#6

“I recently bought a 2010 Toyota Corolla. The saleswoman said that the car had synthetic motor oil in it (and allowed longer oil-change intervals). She also said that I had to use synthetic.”

I learned, many years ago, to NOT take any technical advice from car sales people.
Trust me–more often than not, their understanding of the mechanical aspects of the cars that they are selling is…not very good.

If you want the official, authoritative word, simply open the glove compartment, take out the Owner’s Manual, and see what it says regarding both the type of oil required and the oil change interval that is recommended.

Pay careful attention to the Severe Service maintenance schedule, which many–perhaps most–cars actually fall into. The “standard” maintenance schedule, in many cases, is a best-case scenario that may not apply to your usual driving patterns.


#7

McCahill may be dead, but I still like reading his book “What You Should Know About Cars”. Of course, his opinion on multiviscosity oil was probably out of date even when the book was published in the early 1960’s. He wrote so well that he was believable.


#8

“McCahill…”

And who else would have told you that a Pontiac station wagon handled like a hippopotamus on a wet river bank?


#9

Please post the grade/specification for the oil. “ILSAC” is the organization, not the grade, kind of like “SAE” is the organization. Only if you post the grade/spec for the oil can we tell if the saleswoman was correct.


#10

I’ve only met ONE car sales person who actually knew a little bit about the mechanics of a car…MOST couldn’t even show you HOW to do an oil change…

First off…making the claim that you can extend the oil change interval by using synthetic is bogus…If you do and you have any engine problems Toyota can/will void any warranty claim because you extended the oil change interval beyond the manufacturers recommendations.

Second - Toyota has never recommended synthetic oil for any of their cars…

Go by the manuals recommendations.


#11

Or that the instrument panel on the Triumph TR2 was “as easy to read as a Marilyn Monroe calender, and almost as informative”


#12

I’m not a fan of the “synthetic oils allow for longer oil change intervals” thing. I prefer to change my oil every 3,500 miles or so to get rid of the dirt that accumulates in it. Check your owner’s manual. If synthetic is a requirement, it will be very clearly stated therein. If your Corolla does not require it, just use regular oil and change it reasonably often. Synthetics are superior in some conditions, like excessive heat and stress due to sustained hard running, but these are conditions that a Corolla will not have to deal with unless it is in an endurance race;-) I tend to run my cars ‘till the wheels fall off, and regular ol’ dino oil serves me very well.


#13

Second - Toyota has never recommended synthetic oil for any of their cars…

Really? Then why do they market synthetic oil under the Toyota brand name? Others have reported that they DO recommend it.

This webpage is temporarily down, but I have pasted below text from it:

http://www.toyota.ca/cgi-bin/WebObje...400140e.html

—Begin Quote—

WHAT IS IT?
… Conventional oils are refined from base stocks, whereas synthetic oil is
man made by combining specific chemicals to produce a synthetic base stock

WHY DOES IT DO?
… Synthetic oil protects your engine and performs better in both cold and
hot temperatures
… Reduces engine friction more effectively, especially at low temperatures,
thereby increasing horsepower and decreasing fuel consumption
… Synthetic oil minimizes on-going wear and deterioration and extends engine
life

WHEN TO REPLACE?
… The oil and filter should be changed according to the Toyota Maintenance
Menu

FEATURES
… Pour point of -51?C means it keeps flowing even at very low temperatures
… Withstands the extremes of very high engine temperatures without thermal
breakdown and maintains viscosity control
… Excellent low and high temperature performance combine to produce a single
all-season lubricant suitable for the extremes of the Canadian climate

—End Quote—


#14

0W-20 or 5W-20

I have found both synthetic and conventional versions of the 5W-20 with the ILSAC spec/cert/approval. Haven’t been able to for the 0W-20. I figure it might be like asphalt PG grades where some just can’t be produced naturally.


#15

Nice post time.


#16

Your owners’ manual is the definitive answer on whether you need synthetic as well as what spec oil you should be using. Any oil that meets or exceeds the owner’s manual requirements is good. Where only dino is required, synthetic exceeds the requirements.

I personally am not a fan of extending oil change intervals because synthetic is being used. My goal is to extend the engine’s life, not the oils. All oils dino and synthetic become contaminated with the same particulates and blowby dilution.

I’ve also yet to see any data that synthetic extends the life of engines that don’t need it. I’ve kept engines perfectly healthy for hundreds of thousands of miles using dino. I’ve only used dino (never had an engine that spec’d synthetic) and never worn an engine out. Regular oil and filter changes as well as regular maintenance will keep any properly designed and manufactured engine running for hundreds of thousands of miles. Engines with design or manufacturing defects cannot be saved by synthetic.