No idea what oil was last put in car __

[turboblag]

So, this could be a noobish question ... but, oh well!

Yesterday, I picked up an 05 350Z 😁 I’ve been looking around and have eventually found that 5w30 fully synthetic is the best oil to use (makes sense)

My question, however, is whether there’s any way to figure out what oil was last put in and whether it’s pretty safe to assume people only use fully synthetic these days?

Last service was oct 18 but it doesn’t note what oil was used. After looking through the many service receipts, I’ve found one that lists 5w-30 part synthetic ... but that was back in 2008.

Should I just get some 5w-30 fully synthetic and assume it’ll be fine?

[InitialDave]

Your easiest option is to just do the oil change if you're not confident it's got what you want in there. Assuming you'd do an annual change anyway, a few months early is hardly going to hurt anything.

[anonymous-user]

For a top up yes, All API oils have to mix with every other API oil its part of the requirements to meet the specification. So the latest fully synthetic SM 0w 50 mixes with 10 year old mineral oil, Do you get the beautiful of the latest expensive oil of you add a pint to some crap already your engine no, but you can't damage an engine, they have to mix..If you have the wrong spec in your engine adding a little of the right stuff want improve the unknown crap.

[paintman]

InitialDave said:

Your easiest option is to just do the oil change if you're not confident it's got what you want in there. Assuming you'd do an annual change anyway, a few months early is hardly going to hurt anything.

^^^^This.
Assume that it needs all filters & fluids changing & you won't go wrong. You'll then know that it's actually been done & what fluids have been used.

[p4cks]

Berw said:

Do you get the beautiful of the latest expensive oil of you add a pint to some crap already your engine no, but you can't damage an engine

I tried I really did, but what the fk does this mean?

[anonymous-user]

Sorry spell check, 'benefit'. If your just topping up something unknown until the next oil change then you are not 'improving' the oil by adding something expensive, if the sump is 90% full of crap and you add 10% of real quality you just get 100% crap.

[Pit Pony]

I once paid 40 quid for a car that had a full service history over 15 years to 17k. The second owner took it from 17k to 70k in 2 years and never serviced it, hence the price. He was selling due to head gasket failure.
Anyway i did yhe head gasket, and changed the oil, putting in the cheapest correct spec semi synthetic in. What came out wss lumpy treacle. Ran it for 500 miles and then changed it again. And again 500 miles after that. But that time with oil bought from.the main dealer with a trade club discount.
Happy days. I kept it another 50k until.the head gasket went again. Its still.alive 15 years because i saw it on the owners club website on a show report.

[p4cks]

Berw said:

Sorry spell check, 'benefit'. If your just topping up something unknown until the next oil change then you are not 'improving' the oil by adding something expensive, if the sump is 90% full of crap and you add 10% of real quality you just get 100% crap.

Ahh getcha, I agree. I think the OP might be being a little paranoid