To change transmition fluids or not to change and synthetic or standard

My Ford focus is up for a transmition fluid change per the valvoline oil change marts. Just how important is this, I make sure the fluids stay topped off and have never had any problems with transmitions ever in any car I have ever owned. Have I just been lucky for 20 plus years?

My second question is should i be paying more to use synthetic or not. Once again I change the oil regularly in my vehicles at 5000 miles (instead of the recommended 3000)and make sure the oil stays topped off. I once again have never had a problem.

Makes me wonder if synthetic oils and the 3000 recommended changes are just ploys of the big oil companies, no they would never do that???

First Sergeant,
Hi, first, I strongly recommend that DO follow the recommended mileage for oil changes and change your oil at 3000 miles. Oil is the blood of the engine and with dirty blood the engine will wear out faster. I also recommend using synthetic oils and transmission fluids. Google oil specs on line and you will see how much lower the friction losses in your engine will be with synthetics. Additionally, synthetics break down much more slowly than dino juice. I have an Olds 88 with 230,000 miles and the engine has factory new compression across all cylinders, doesn’t smoke and uses zero oil between changes. Additionally, I get 3 to 4 miles per gallon more than with dino oil. I also recommend synthetic gear and transmission fluids for longer gear wear and smoother shifting. I hope this helps. All the best and Semper fi! Col K

The most important thing that you should do is not let quickie mart-type car “care” places do anything to your car and certainly don’t let them tell you what maintenance is due and when.

Find a local, independent mechanic with a decent reputation and have them do your work (even oil changes), and use an owner’s manual for the car to determine what maintenance needs to be done and when. This includes things like the specs on what kinds of fluids to use.

One exception to the owner’s manual would actually be the transmission fluid - most manufacturers give crazy and unhealthy service intervals. The best way to a long life for the transmission is to have the pan dropped & filter changed every 30K miles. (Valvoline will want to just “flush” it. In this case, the filter is not changed and there is no opportunity to inspect the contents of the pan. Flushing is more about them owning the flush machine & getting it to pay off).

You didn’t say what year the Focus is, but you probably need Mercon V fluid. This info is also in the owner’s manual. If it doesn’t say synthetic, then you don’t need synthetic

If you are not overloading the transmission or live on the Alaska North slope, the normal fluid specified in the owner’s manual should be OK if you change it and the filter every 30,000 miles. I worked in the Arctic and the local dealer made many drivers very happy by installing synthetic fluid and axle oils. Why do you use the Valvoline charts rather than the owner’s manual?

With respect to oil changes, again, if your car does not require it (read the manual), and you practice normal driving in a temperate climate, normal “dino” oil is OK, as long as you change it often enough. For most driving I would go 3000-4000 miles; in older cars with carburetors and loose tolerances, 3000 miles is considered best.

There are no sinister themes going on here; each type of lubricant has its place. The only misinformation you have been fed (or made yourself to believe) is that synthetic oil allows you to EXTEND the drain interval, just because it costs more. Normal synthetics have the same ADDITIVE package as regular oils, and it’s those additives getting used up that determines the drain interval.

You have not told us what year car you drive and how many miles are on it or your driving style.

Since you seem to have had no problems so far, I would not switch to synthetic. Be assured, hoever, that towing a trailer across the South West in July with a cheap non-synthetic oil at 4999 miles in the crankcase will definitely cause either excessive engine wear or FAILURE.

If you read military history, you may know that Hitler’s tanks and trucks probably would have reached Moscow if they all had synthetic lube oil and other fluids!!! Synthetics are for extreme conditions mostly.

In short, I have friends, mostly engineers, who want to keep their cars for at least 300,000 miles or 20 years. They use synthetic oil of the right VISCOSITY, and change it according to the owner’s manual, 5000 miles for Toyotas. They also change transmission fluid and filter at 30,000 miles even if the manual does not call for it. And they flush their radiator every 4 years or 50,000 miles.

Ford went out on a limb with their “Duratec” engines with supposedly low mainteance. The Achilles heel in that was the coolant life will not go 100,000 miles and transmission have to have their fluids changed every 30,000 miles or so.

So the Ford ploy is to sell “low maintenance”, the real guilty party!

If your owners manual calls for regular fluids then you’re just wasting your money on synthetics.

Generally the carmakers service intervals are more trustworthy than what some place that’s trying to sell you oil changes says.

Put the same fluid in your auto transmission that it came out of the factory with.
Anything else is a crap shoot.

I would use the vehicle manual for service intervals. That said I would not have tranny flushed. I have heard horror stories on sludge dislodging and ruining the tranny. Drop pan and change filter. I do use synthetic oil. 99 Camry has small engine oil ports and sludges and kills the engine. Synthetic will not sludge and lasts longer.

Does your owner’s manual tell you to change oil every 3000 miles? I doubt it. Unless your car sees severe service, you should change oil when Ford tells you to. I would guess it’s more like every 7500 miles. That is the case for 2007 and newer Ford Focus.

Over the years I have been on this URL, there have been many discussions on oil usage and change schedules. Frankly, most of them involve a variety of opinions that have little connection with reality, but a lot of confidence that each person’s personal decision is the only right one. A very dominant view is that anyone who cares for his car at all will change oil every 3,000 miles. Others are that synthetics are a hoax used only by gullible people, etc, etc.

I tired of this mess of bad information, and last year, let my 2002 Sienna with 158,000 miles and Mobil-1 EP go 8800 miles and sent in a sample to a lab to be tested.

I was amazed at all the information you get in your results. Not just the condition of the oil, mine was good and had enough additives to go at least to 10,000 miles. Now, I change oil at 8,000 miles on the EP. FOR MY CURRENT DRIVING PATTERN! If I change driving pattern, I will have it tested again.

But, also it’s like a microscopic look at the inside of your engine. Bearing wear; valve train wear; contamination; blow-by; and more. Great stuff, more than any mechanic could ever tell you.

So, I think an occasional oil test is worth it just for mechanical feedback on your motor.

But, also it will tell YOU on YOUR car, with YOUR driving pattern how often to change the oil for maximum motor life. It will be different on different cars with different driving patterns, as well as over the life of your car as perhaps it changes with normal wear.

If you don’t want to bother, any of the common choices are probably good.

Every 3,000 miles – though I have been taken to task for that by a chap who apparently thinks you should have to ask the government for permission to change your oil to save the planet. Yes, you will almost certainly be wasting good oil, but if it floats your boat, it’s your car and your money. And, it sure won’t hurt your car. But, no, 3,000 mile oil changes for normal service is not needed at all. And, yes, it is a ploy, but by the oil change folks. The oil companies are making good oils that don’t need to be replaced that often in normal service.

Per the car manual. This is a popular viewpoint, but the problem is the manufacturers have not told us what target mileage they intend for the life of the motor. If you know you plan to trade before the car fails, this may well be a valid choice. If you plan to drive your car for 300,000 miles it may not be good enough.

Or, as I stated, actually test the oil on your car for your own driving pattern.

Docnick is one of my personal heroes. But, I am tentatively planning an experiment to compare standard synthetic oil to a good dino, to see the additive life issue he stated above. I do not intend to run either oil the same 8800 miles I ran on EP, but may test them both for 5,000 or 6,000 miles. I have tired of all the bad information given here on oil, and want to see for myself what is right, though I am not at all saying my hero’s opinion is wrong. I just want to see for myself.

My friend has a 2002 Focus and when I change the oil I sometimes use Motorcraft 5w-20 pruchased at Wal-Mart. It is a synthetic blend and doesn’t cost much more than regular oil. I have been changing it every 5k miles with no problems which is what the manual calls for.


Muchas Gracias Irlandes! Synthetics perform well in extreme conditions (hot, cold, heavy bearing loads). If your operating conditions are totally normal, a non-synthetic is as good as a synthetic.

Just this weekend the world long distance champ, owner of a 1966 Volvo with over 2.8 million miles on it was interviewed. He drives 50,000-80,000 miles a year throughout the US; perfect driving environment and does not use synthetic.

Your driving environment in Mexico may well warrant the benefits of Synthetic because of the extreme temperatures. In fact, if I was in your shoes, I would use the same Mobil 1.

The experiment will tell you a lot; please let us know how the results show up!

[i]What kind of transmission are we talking about, an automatic or a manual transmission?[/i]

Here is my advice:

-If your transmission is an automatic transmission, I would have the fluid changed every 30,000 miles. I would use the automatic transmission fluid (ATF) recommended in the owner’s manual, meaning I would only use synthetic ATF if it is required.

-If your transmission is a manual transmission, it probably calls for some kind of gear oil. My manual transmission in my Civic requires 10W-30, but Honda recommends its brand of manual transmission fluid (MTF), which is 10W-30 oil with particular additives. At the price Honda charges, the oil in its MTF is probably synthetic. I use synthetic 10W-30 oil in my manual transmission. I recommend you change your MTF at least every 60,000 miles and use the proper gear oil. To be safe, I would consider buying the MTF at a Ford dealership’s parts department. You might be able to find the right MTF elsewhere cheaper, but if you do, make sure you don’t buy the wrong MTF.

-When it comes to the oil, what kind is recommended in your owner’s manual? How often does the owner’s manual indicate it should be changed? Are there two maintenance schedules (one for normal use, and one for use in extreme conditions)? If so, I would follow the one for “extreme conditions.”

-Unless your owner’s manual says it is required, I believe synthetic oil is a waste of money.

-If you choose to use synthetic oil, don’t extend your oil change intervals past what is recommended in your owner’s manual.

-Don’t shorten your oil change intervals shorter than what is called for on the “extreme conditions” schedule. Doing so only wastes your money and time.