Anyway to tell what kind of engine oil is in a car??

[mAdD INDIAN]

I checked the oil level in the 240SX and it was pretty low and I wanted to fill it up. However I don't know what kind of oil was in the car previously and I don't think the dealer knows either.

So what are my options?? I doubt it would be safe to put in a 5W-30 if the engine already has 10W-30 instead? I don't think I can mix different viscousity level oils. Also what if the car has synethic and I put in dino oil??

What I'm thinking of doing is doing a full engine flush and then putting in synthetic?? Is it a good idea to put synthetic oil in an engine with about 75K miles??

Can I tell what kind of oil is in the car by looking at it??

Also, I took the car around the block in the snow for the first time today, it was ok. The rear end would move side-to-side if the wheels got caught in the ruts in the snow, but it was controllable. It only swapped ends if I intedended to. I still wouldn't drive it on the main roads till I put some weight in the back and put some snow tires on though.

 

[DuffmanOhYeah]

As far as manufacturer suggested oil, it should be listed in your manual. If you are really concerned, just change the oil and fill it up with x quarts of whatever. It is my contention that unless you are running a high performance vehicle, the oil you use really don't mean sh!t. 10W-30 should probably do you fine. In all honesty, I really wouldn;t wory about it, just as long as you maintain adequate levels, and aren;t going with some really whack viscosity.

 

[desertdweller]

Just change the oil and put whatever you want in it.

Just stay away from penzoil.


DD

 

[madwoodee]

synthetic is better for your car, but more expensive

 

[Damage]

If you have any kind of warantee on the car, use whatever is says in the manual. If not, try to match your oil viscosity to the usual temperature of the climate you are in. In Southern California it gets a little hotter, so I generally run a heavier oil (20-50 in my motorcycles) , in colder temps however a thinner oil will come up to temperature faster and start protecting the engine earlier after startup.

Synthetics are great, however if you don't have ready access to them and are a quart low, most people don't recommend mixing them in the engine. If you get a semi-synthetic (pre-blended) you get the best of both worlds and it isn't quite as expensive.

Hope this helps.

 

[TuffGuy]

if your car is high mileage and you've been using regular oil, don't use synthetic.

 

[Cyberian]

<< if your car is high mileage and you've been using regular oil, don't use synthetic. >>

I've heard this before. Do you (or anyone) know why?

 

[etech]

Amsoil is right up there with Amway as far as marketing their products through a chain of dealers, but I agree with this person's post about using synthetic in older cars. When synthetics first came out it did not have the compounds to cause seals to swell and the and they would leak in older cars. Both engine seals and the synthetics have improved and it has become one of those myths that cannot be killed.


Synthetic in older cars

In Reply to: Synthetic in older cars posted by Del on October 13, 2001 at 22:31:35:
Del,

This is partially a re-post from another question that deals with the same fallacy about synthetic oil. Synthetic oil does not damage seals or gaskets, the word that should be used is "exposes" bad seals and gaskets.

Flushing and adding synthetic oil will not harm your engine in any way. It could "expose" a cracked seal or gasket though. Regular petroleum oil has a by-product, varnish, it coats your seals and gaskets. Varnish is a bad thing, it keeps your oil from contacting and wetting the surface of the gasket, as time goes by the seal dries up and cracks underneath the varnish. Your car doesn't leak oil because the varnish helps keep the seal. Adding synthetic oil dissolves varnish. Potentially exposing a damaged seal or gasket.

Now here's the good news. That's a rare situation. I have had many high milage customers and not one has reported an oil leak to me. But the potential is there. If a leak is exposed in your case it was trouble waiting to happen anyway. Isn't it better to find a bad gasket or seal in your driveway, than to be on the road somewhere when it decides to giveout? Leaving you stranded and possibly causing engine damage because all your oil was thrown down the highway? If you do get a minor leak, give it some time. Amsoil has special additives to wet seals and gaskets and cause them to swell and reseal a leak. If after two or three weeks there is still a leak, you'll need to have the seal or gasket replaced.

Hope this helped,

edit/
If you have a couple of hours to spend reading there is a thread at Edmunds town hall just on the subject of synthetics
Synthetic motor oil

 

[Baffler]

<< if your car is high mileage and you've been using regular oil, don't use synthetic. >>

I've heard this before. Do you (or anyone) know why?


Okay i had to make my first post beacuse this is probably (spelling?) the only thing i learnt while working for Statoil

Well, newer syntetic oils has better cleaning effect on your engine than the old mineral once.
So if you have used mineral oil all the time and switch to a syntetic your engine can start to leak beacuse the oil desolves the old layers of dirt and stuff that actually made the engine not to leak.
Allright, take care

 

[Thegonagle]

You can mix different brands and weights of oil, but change it soon to be sure all the additives are compatible.

Don't do any flush. Don't put anything except oil in there. If really you want to flush it, change the oil then change it again in 100-200 miles. I really don't see the point though. Changing the oil is flushing it.

The point of not using synth in an older engine is that leaks may develop in the gaskets and seals that are "used" to conventional oil, because they shrink up. I may be wrong, but I say whatever. If the seal or gasket shrinks and starts leaking, it was probably about to leak anyway.

 

[db]

Unless you have very high performance engine, live in cold country, or are trying to increase poor gas milage, there's no reason to use synthetic.

 

[Zenmervolt]

<< Unless you have very high performance engine, live in cold country, or are trying to increase poor gas milage, there's no reason to use synthetic. >>

Also, synthetic is best for very hot climates or engines in heavy use. I prefer to use synthetic in my two air-cooled engines (motorcycle and 914) because they run hotter and synthetic is better protection against thermal breakdown.

ZV

 

[mAdD INDIAN]

<< Unless you have very high performance engine, live in cold country, or are trying to increase poor gas milage, there's no reason to use synthetic. >>


I live in a cold climate (Canada).

The car is not that old, its a 1995 and is relatively low mileage, around 75K miles.