What to do when you cannot get past info on what kind of oil previous owner used. 1989, 50K miles. If it has been synthetic, I have no problem using regular oil. If it has been regular oil, I do not want use synthetic. Question is: When you don't know, can I just use my favorite, Valvoline 10W30 ?

Boatman, in south FL

 

gahh, just taste it and see what it is.



j/k haha, I dunno man, ive been in the situation before with a previous car, and just decided to go synthetic.

 

I went to the Valvoline site. They have an oil called Dura-Blend. It is a mixture of synthetic and conventional oil. This may be the way to go.
I have also asked them the same question about the switch.
I used their Max-Life in the 79 with good results.

 

why are you so concerned?

Switch to synthetic and be done with it. Whatever mineral oil is left behind will be absorbed by the synthetic on the first pass... and will be gone by the time you change the oil next.

 

Why are you concerned?
You can use conventional or synthetic motor oil... it does not matter what the previous owner used. If you are worried about the myths that changing to synthetic will cause leaks... it is just that.... a myth.

Synthetics have a number of benefits. They provide better low temperature lubrication, better high temperature protection, and allow longer oil change intervals.

I'd go with a synthetic .... in 5W30 from a Brand you trust.
For me that is Shell or Mobil... as first choice, with Quaker and Pennzoil rounding out my top 4. Others will have their own favorites.

 

This stuff is blown way out of proportion.

 

My personal favorite synthetic is Royal Purple. The oil actually is purple.

 

 

Mobile One

 

Thanks forum members. I will take your advice.
Boatman

 

Don't want to hijack this thread but since we're taking about oil, has anyone used that super synthetic mobil one you only change out once a year or every 15,000 miles? Its only a few dollars more than the regular mobil one syntheitc but Im hesistant to wait a year before changing oil.

 

Have not heard about this variant of Mobil 1 ... do you have more details?

 

Saw it at Wal-Mart. Cost about 15% more then regular Mobil 1 syn.

 

I suspect that is the first of the Level 4 synthetics coming out.

Let's back up a bit here... synthetics start as mineral oil. Most "mineral" oils are Level 2.5, whereas synthetics are Level 3.

The "level" refers to the purity, or, how well refined is it.

The main difference between mineral and synthetic is the removal of the waxes that cause heat break down.

It's also why synthetics are prone to leakage - they don't "cause" leaks, they just find them - the wax is gone; the oil will flow better.

If I remember rightly, the Shell Helix that is used in the Ferrari Enzo is like $70 a quart, and requires like 12 quarts!!! I think that stuff may also be Level 4.

The Level 4 will be even better refined, less prone to thermal breakdown and less prone to viscosity breakdown caused by stray gas vapour entering into the crankcase. The viscosity breakdown is also enhanced by the chemical additives introduced during manufacturing.

Viscosity breakdown is the worst thing... it's caused by short trips, where the oil does not get a chance to warm up. Synthetics are reasonably immune to this. Mineral oils are not.

Mineral oils require that heating process, so they can burn off the bad stuff and keep their viscosity where it belongs. It's why conventional oils require a 3-month/3000 mile change interval.

With synthetics, I go about 5 months/5000 miles or so.

I hope this helps clarify some of the issues involving oil.

 

The first tip is to never ask for oil advice here.

Most guys use Mobil 1 but don't leave it in long enough to benefit from it, so they just **** their money away.

I say, if you have no leaks, use Mobil 1. If after the first few oil changes you're still not getting more than 4K before it's dirty, then just use dino oil and save your $.

Dirty oil doesn't mean it's used up, but if it's getting dirty before the oil breaks down, you should be changing it anyways.

How long your oil lasts depends on how tight your engine is, how much blowby, valve seal leaks, and how dirty the air it breathes in.

 

this stuff is alsome, I can actually feel the difference after a couple of oil changes, the engine runs much smoother. this stuff is supposed to be the best. I put it in my ZF6 trans recently because of the how great it worked for my LT1, the trans is shifting much smoother. mobile 1 is also good.

 

just wanted to thank you for putting this thread on today!!!
I had the same question myself and got the answer I needed..
THANKS AGAIN!!

 

It's a myth to all those who haven't experienced it first hand I suppose.

 

read my post...

 

Go with what the General put in from the factory. Mobil 1 5W30 syn.