When is it too late to use synthetics?

[TTaM]

I have a '98 Ford ZX2 with 78K miles as a daily driver. This has had dino oil its entire life. Well, since I fell into some synthetic, I am thinking of changing. Could I be doing more harm than good? I drive 3K a month, and was hoping to extend the oil change interval to longer than once a month.

[aklim]

When the engine is broken, don't waste any kind of oil on it.

Seriously, I have added synthetic oil into engines which have 90K on the clock. My feeling is that if you start to leak, it is because you have cleaned the engine out with the better detergents and now the gunk that blocked the bad seal is out and the motor is free to leak.

[Marcb]

Switched my 87 300D over to full synthetic at 170k with no problems... switched my 97 Passat TDI to synthetic at 100k and no problems either...

Originally Posted by Marcb

Switched my 87 300D over to full synthetic at 170k with no problems... switched my 97 Passat TDI to synthetic at 100k and no problems either...

Very interesting, 170K is when I switched my 87 300D over to full synthetic!

Also have installed synthetic differential oil, transmission fluid, brake fluid, and am now looking for power steering fluid too. As you can see, I'm a sucker for anything synthetic, even my pants and shirt are synthetic.....wonderful stuff!

[Hatterasguy]

Synthetic causing leaks seems like an old wives tail.

My 245k mile drive train has, Mobil 1 in the engine and rear end. Soon as I fix the trans leak Mobil 1 atf will be going in. I use MB power steering fluid that also seems to be synthetic.

If you want the best and are willing to pay synthetic it the way to go! 0 degree days don't bother things as much that is for sure.

[Ali Al-Chalabi]

Never too late for synthetics. Once switched an 84 325e to Mobil 1 at 200k miles with no problems. My C280 also runs Mobil 1 with no problems or leaks.

[Flash Gordon]

It really depends on how long you plan to keep the car. If you plan to sell it after another 10-40K, it would be a waste of money. But if you plan to keep it to at least 150K, then use synthetic

[Will_w202]

Seriously, I have added synthetic oil into engines which have 90K on the clock. My feeling is that if you start to leak, it is because you have cleaned the engine out with the better detergents and now the gunk that blocked the bad seal is out and the motor is free to leak

That's what happened to me. I changed at 75k, and by 77k I had a puddle. Warranty covered new gaskets galore. Synthetic is far superior! But if you have a questionable seal somewhere, it's gonna leak when the Dino Stopleak gets flushed out.

[rickg]

Been awhile since we had a good oil thread

The whole "oil" debate is kinda moot by now, but in Volkl's situation, I would agree with synth, as long as it doesn't spring leaks. Wow! 3K miles a month?!

[Hatterasguy]

60 quarts! I guess you will be running Mobil 1 in everything! I hope he got a deal.

[Hatterasguy]

Let me guess they fell of the back of a truck!

Any 15w-50? I'll buy some off you. I can get it for $3.99 a quart what is your best price?

[TTaM]

Originally Posted by Hatterasguy

Let me guess they fell of the back of a truck!

Any 15w-50? I'll buy some off you. I can get it for $3.99 a quart what is your best price?

No 15w 50. Autozone was clearing out their inventory, my dad happened to stop in on the right morning. He bought 0w40, 5w30, and 10w30. Sorry, we have 6 cars, all this oil will be used soon enough. An, to be honest, I checked. There is only 24 quarts of Mobile One, the rest are Texaco Havoline Synthetic...

[Honus]

Originally Posted by 123c

...The thing with Mobil 1 is that on older engines it needs to be changed every 3-4 miles for the first few oil changes because it knocks the sludge loose...

You meant to say every 3,000-4,000, right?