Synthetic vs. petroleum oil


#1

I drive a Toyota Yaris, and was convinced to put synthetic oil in the vehicle two oil changes ago. I put in synthetic again last time, but then decided to go back to a semi-synthetic. The mechanic at Walmart said this was not a good idea, but I thought it was another Walmart sales pitch. This was yesterday. Why would this be a bad idea? Will it ruin my engine? Should I go back today and have synthetic oil put in? What is the advantage of synthetic oil?


#2

“The mechanic at Walmart…”

Now that’s an oxymoron. You can change back and forth if you want, just make sure you meet the manufacturer’s requirements for your car.


#3

The mechanic at Walmart

You mean the guy working in the Walmart garage who flunked out of high-school and got his GED on his 4th try???..That Walmart Mechanic???

You can go back and forth between synthetic and regular dyno till your hearts content…Wont’ cause one bit or problem what-so-ever.


#4

Thanks Craig. That’s what I thought…then I had this horrible feeling…what if I’m outwitted by a mechanic at Walmart. It left a sick pit in my stomach.


#5

Yes, Craig is correct that the guy at Wal-Mart (you know, the semi-literate one with no teeth) is not a mechanic, but rather, is just an oil change/tire change technician.

Synthetic oil does have some advantages, namely the ability to start your engine in EXTREMELY low winter temperatures. However, if you live in areas other than Alaska, Northern Minnesota, or perhaps some upper reaches of Maine, a conventional oil of the proper viscosity will probably do nicely for you at less cost.

Synthetic oil will also allow you to go longer between oil changes. However, if your car is under warranty (as I suspect that it is), then you cannot push the time envelope with oil changes and you would be foolish to go against the elapsed time and/or odometer mileage limits specified in the manufacturer’s maintenance schedule.

Or, to put my advice in other terms–If you change your oil every 4,000 miles/4 months, as most people do, then you are paying the price for synthetic oil without getting much benefit. And, if you live where winter temperatures do not typically go below around 20 degrees Fahrenheit, you are also pretty much wasting your money on synthetic oil.

On the other hand, once the warranty is expired, if you want to be able to go perhaps 8,000 miles between oil changes, then I could see the benefit of the extra cost of synthetic oil.

“You pays your money, and you takes your choice”, as the old saying goes.


#6

If you were outwitted by the “mechanic” at Wal-Mart, that would be a sad commentary. But, the fact that you can communicate very well in standard English tells me that the guy at Wal-Mart couldn’t outwit you on his best day.

As you have probably surmised by now, take any advice given by Wal-Mart’s technicians with a grain of salt. Smile at them, and thank them for the advice, and then proceed to ignore it.


#7

“Curly” Joe Howard went to work as a mechanic at WalMart after the clam outwitted him.


#8

Walmart is actually of all quickie lube joints is probably the best by far in terms of not selling uneeded extras. Its sole purpose is to install/sell customer tires and the oil change portion is to keep tire tech lubes busy AND keep you in store to buy anything and everything.

I think the tech really was giving some old “mechanics” tales to you on synthetic. There are qualified compentent mechanics who believe this load of dung too on oil.

I will admit to using Walmart out of convenience to change my engine oil on my previous car 150k-225k miles. Not a single issue for the paltry $13 charged at the time.


#9

In an emergency dead battery situation with a friend a few years back (her car) I used Walmart’s shop, and I have to agree with Andrew. While they only seemed to be set up for basic things like tires, oil changes, and batteries, the guy there seemed knowledgable and competent, properly checked the charging system (it passed) and did the battery deed. He didn’t try to sell my friend anything beyond the battery and had an ASE patch…although I didn’t see in what. I’m also unfamiliar with any issues of dishonesty with WalMart, like the ones with Sears.

I have to agree with Andrew too that the myth persists even among knowledgable people.

I can remember back when radials came out. There was a myth that radials could not be switched to the other side of the car during rotations. That was before directional radials. There was also a myth that you could only use radials on cars designed for it or the handling would get weird. Eventually those myths disappeared. Perhaps the same will happen with the synthetic vs. dino switching myths.


#10

My experience with WalMart is that its personnel in the auto area seem to want to do what they think is best for the customer. Myths about which motor oil is best and whether or not to change brands or mix brands have been going around for years. Back in 1955, my Dad bought the newest car we had ever owned–a 1954 Buick. A trusted mechanic recommended that we only use MacMillan Ring Free motor oil in the car if we wanted it to last, which we did. MacMillan oil wasn’t available everywhere, so we always carried an extra quart if we needed it. After the mechanic closed his shop, we switched to Quaker State for convenience. The car had about 65,000 miles when we made the switch. The car went on for 100,000 more miles while we had owned it and never had the heads or pan off the engine, nor did it use any oil. It seems to me that many mechanics for one reason or another prefer a certain brand of motor oil. Fifty years ago we used to have this debate as to whether or not we should use detergent oil or non-detergent oil in a car and whether we could switch back and forth. Now the debate is about synthetic vs petroleum based oil.

My guess is that the WalMart technician really believes what he is saying. I’ve had two experiences with WalMart that suggest they keep the customers in mind:

  1. I had to replace a battery in my in-laws car. I had the replacement installed at a WalMart. They didn’t drive the car very much and when I brought the car to my house to sell it, the battery wouldn’t turn the car over if it sat more than 2 days. I traced the problem to the battery. I took the car to my local WalMart (not the one that installed the battery) and they replaced the battery for free with no questions asked.

  2. I bought a couple of inexpensive tires for my then 16 year old 1978 Oldsmobile Cutlass. Nine years later I found that the car vibrated badly when I went over 45 miles per hour. I did a quick inspection and found out that the wheel weights had come loose on the right front tire. I took the weights off which helped, but there was still some vibration. I was going to go to my independent tire store and have the right front tire rebalanced when I found the original tire invoice from WalMart in the glove compartment and it stated that I had lifetime balancing. I took the car to WalMart and explained the problem and what I had done. The service manager asked me how bad the problem was. I replied, “I was coming down the interstate when a Ferrari started to pass me. I pushed the pedal down, but at 120 miles per hour it vibrated so badly that I had to back off and let him pass me. I was terribly embarrassed”. The service manager looked at my 25 year old car and then at me and said, “I think I had better balance both front wheels”. There was no charge.

In the case of the OP, I think the WalMart representative, misguided as he might be, really did have your interest in mind.


#11

The stuff you hear! I know a chemical engineer who doesn’t believe that there is an ozone layer. If he does believe in it, he sure thinks that we can’t hurt it or save it. I didn’t expect to hear that from him. An auto mechanic with any and every qualification will say anything. Keep checking up on them. I love synthetic oil too, but It hasn’t made me crazier than I would have been without it. I would have been nuts anyway. No matter what oil you use; when you are taking it out of an engine and you get some of it on you, it will never match what you’re wearing.