jyoon

Can you tell used synthetic oil from standard? If so, how can you tell? The po said he put synthetic oil in my car and it doesn't leak. I don't know for sure if he did or not. I don't want to put synthetic and have it leak if it isn't currently sythetic.

tk's944

Putting synthetic oil in does not make your car leak.

2bridges

to answer your question - no you will not be able to identify if used oil is synthetic without analysis

ausgeflippt951

You'll never know unless you're a petroleum engineer w/ a lab.

oh and synthetic does not make your car leak, so long as it's not too high-mileage.

inactiveuser92616

if you were really good you could tell by taste. Kind of like decaff....

2bridges

Although a synthetic oil will not cause ar leak - synthetic oil is lighter. As such a leak will more substancial with synthetics. A minimal seep with dino oil can in fact be a leak with synthetic.

It is common for an older/higher mileage engines with no apparent leaks or oil consumtion to leak and consume oil when switched from dino to sythetic. The synthetic oil is not the "cause", just difference in oil properties. All symantics - synthetics are not always the best option

CarbonRevo

I recently switched my truck from 10w-40 regular off the shelf crap, to Amsoil 10w-40 high performance. My truck burns a little oil, but the other day on a corner, the oil light flashed on. I pulled over, and no oil on the dipstick! eek! Took 2 quarts to get it back to the full mark (1 quart to get a reading halfway to full on dipstick). No damage was done (so I think). Does synthetic burn off easier? If dino oil 10w-40 would barely burn off, but synthetic 10w-40 burns off faster...should I run a higher weight? O, I did have the oil in for about 6k miles/ 6 months.

You live and learn, I regiously check it now!

Jfrahm

You could try putting samples of your oil and a dino oil of the same grade into a deep freeze and then seeing if one is a lot thicker than the other.

Zero10

Synthetic does not 'burn off' easier, it is much more difficult to actually burn a synthetic oil, that's the point. What does happen is the molecules are typically smaller, and they have much better adhesive properties, so they end up where they don't belong (in your cylinders during combustion, or on the ground, or in my case all over the crossmember and the lower parts of the suspension, whatever).
Synthetic does not cause oil leaks by any stretch of the imagination, however if your engine already leaks, don't expect it to get any better.

Is that a reason to run conventional oils instead? Heck no. Especially if your car is turbocharged. I could make some kind of crazy analogy here, but I think you get the point.

As for running a truck 2 qts low, if the oil light flashed and that's it, don't lose any sleep over it. If you drove with the oil light on for a couple hours, buy a new engine You were running synthetic, it has an excellent film strength and very good lubricating abilities, that's exactly why you run synthetic, it can cope for a split second without oil pressure.

Tms951

Drain the oil and then put synthetic in it. Then you will know whats in there. I would never drive around in a car with fluids from the PO, unless he ha a reciept for some thing like gear oil. For your own piece of mind just change the oil.

jyoon

i'm gonna change the oil, but i'm not sure what to put in. the car doesn't leak any oil now and i don't want it to leak. i haven't driven the car much, but i do notice the oil looks awfully clean. my friend says the synthetic stuff smells different. the freeze idea makes some sense.

PorscheDoc

Synthetic does have a slightly different smell to it than dino oil, but unless you are doing a lot of oil changes (ie, work in a shop), you probably aren't going to be able to pick it out.

gstreev

My car leaked a lot more when I switched to synthetic. You may want to try
a synth blend 1st. I used 10-30 Mobil 1.

SD Porsche Fan

Just taste it. If it tastes like an old dino you'll know!

Geneqco

Drain some oil into a pan and fry some chips in it - if they tatse like Macca's, it's synthetic!