Car dealer recommended synthetic motor oil (more$) but friend of my said don't for older cars, why?

Question

Car dealer recommended synthetic oil(more money) and said it will last for 5000 miles and 6 months so I don't have to change oil as often. But my friend told me synthetic oil is good for hot temperature area and new cars but probably not as good for older cars. Any suggestions or explaination of the differece in oil is welcome.

Answer 1

Synthetic oil wont hurt older engines at all. In fact it will help. Synthetic oils help with better viscosity at high temps, better detergeants and additives. So... dont worry. :)

PS- to say to the persons comment below. Synthetic is made with the same base oil as regular oil. Base oil looks like water after it has been refined. Then after the additives and detergeants are added it looks yellowish. Synthetic just has different and better additives to it.

Answer 2

I did a good deal of research on this subject too late after an independent shop changed the oil in my 2001 Audi S4 from regular oil to synthetic. Somewhere along the line, someone else had changed from the synthetic it was born with to the older sort. The result was a $4,000 disaster. It began to leak within days from at least five places, including gaskets and the front oil seal, which spewed oil onto the timing belt I had just had replaced by the independent who changed the oil. My research turned this up: there is wide experience that with SOME older cars (80k miles in my case), changing to synthetic oil brings on oil leaks. I don t know whether the newer synthetics made for older cars also causes this problem. I suspect that the very reason synthetics for older cars exist is that this problem is a well-known secret the car companies and oil vendors know about but do not want to admit due to the likely rash of small claims lawsuits. I asked around in addition to web research. A friend had had exactly the same experience with an older, beautiful Camaro. So the risk exists. It is not clear why, and it is also not clear why not every older car switching to synthetics will have this problem. The bottom line is that the half-and-half approach, using a synthetic specifically for older cars (Castrol GTX High-Mileage for example; Mobil also has a high-mileage synthetic) might be a good way to start if you want to go to synthetics.

Answer 3

I don't know much about the difference between syntheticand non-synthetic oils (except that synthetic oils are made from processed stuff instead of natural petroleum or whatever), but I *DO* have an older car with about 200,000 miles on it, and my fiance is a mechanic. He recommends good synthetic oils because it DOES last longer and does help protect your engine better. Listen to the dealer.

Answer 4

Synthetic oil was a fad a few years back. It's made from petroleum, by the way. I used it for a while but I switched back after reading that there was nothing special about it. I finally got rid of my car. What a money saver!

Regarding regular oil, Consumer Reports did an article that said basically to use the recommended grade, but don't pay extra for the brand name. Petroleum scientists know how to brew up some pretty good stuff.

Answer 5

One reason is the oil can be in service longer. Putting synthetics in an older engine can cause leaks, one thing you need to ask about the brand of oil is does it have a seal enhancer. Sometimes synthetic oils clean up particles away from areas that will leak after oil is installed. I myself would not put in a older engine too many things can happen mainly bad leakage in a short amount of time. NOT GOOD!!!!

Answer 6

Listen to Doug M above. Here is my data Chevy Astro Van 230,000 same engine, always used synthetic, Chevy Truck 289,000 switched to synthetic when I bought it at 90,000.

Don't know how folks get of saying it no different. I would agree though that a good oil, synthetic or not is probably all you need if changed regularly.

BTW, I mix the two all the time with no problems.

Answer 7

I've changed to synthetic oil in vehicles with over 200,000 miles on them before with no problems. It all depends on the condition of the engine before you switch. If you're engine isn't using excessive amounts of oil now, it won't when you change and in some cases will use less.
I've logged 750,000 miles or more in the last 10 years and use nothing but synthetic oil in all my vehicles.

Answer 8

synthetic oil is very good for new engines but if you use it on a used motor it will make it burn oil. It's too slick and goes by the oil rings

Answer 9

For one thing older cars have different tolerances as in my case I tried to upgrade and the oil was to fine and leaked into the cylinders in turn fouling the plugs and ruining my tune up
once i returned to old oil and new spark plugs everything was OK

Answer 10

if your older car has warn seals and rings synthetic oil can find them easier than regular oil.since synthetic is thinner.if you have week seals and gaskets,it can leak out faster.it is a waist of your money to let it ooze out of your engine.