I have had 4 Zs and change the oil and every 3000 miles using Mobil 1 Fully synthetic.

 

I have just bought a 3 litre Peugeot 605 coupe (Its not that bad it does have four pot Brembos and I still have a Z) Anyway back to the question.

 

The Peugeot uses synthetic or semi-synthetic oil and the manufacturers recommended service interval is to change it every 20,000 miles. (The oil, not the car) I know that the Z is an older car, but if oil has improved that much, are we wasting money by changing the oil in our Zs so often?

How much is oil?

 

How much is an engine/turbo re-build?

 

Still want to try leaving it in for 20k?:eek:

Change the oil every 6000 miles or 6 months - I'd rather do this every month than fork out for a new engine / rebuild....

but its peace of mind really, esp on an older high performance car.

 

cars in the states now are good for 50k between oil services!!!:eek:

 

our mercs at work are often 20-25k+

 

i still do mine at 3k! :rolleyes: thats why fully synth oil is really overkill. use a decent semi - synth. imo

i make a it practice to change my oil every 6 months

 

regardless how many miles i put on ..

 

i read somewhere to make a zed last forever change oil

as often as possible ..

 

 

power to zed owners

I tend to do mine whenever I'm bored... So about once a week then ;)

 

Seriously, probably every 1500 miles given how far the car has moved in the past year..

Probably do change too often, but that's better than not often enough.

 

Like someone said, it's peace of mind. If the oil is black and disgusting when it comes out then it's doing it's job.

 

I justify my frequent (3000 miles) changes becuase I do mostly short journeys (~16 miles to work), if it was all motorway stuff then I would move the changes further apart.

 

IMO I think it's best to use a fully synth because I reckon that the superiour properties at higher temps are more likely to resist gooing up the turbo shafts and wrecking the seals.

I heard the reason for fully synth is that semi can leave a laquer type coating on the journals of the turbos = knackered turbos after a while... Worth the extra £20 for some decent oil when you look at it like that really.....

 

 

CheerZ,

 

Andy

Originally posted by andyduff

I heard the reason for fully synth is that semi can leave a laquer type coating on the journals of the turbos = knackered turbos after a while... Worth the extra £20 for some decent oil when you look at it like that really.....

 

 

CheerZ,

 

Andy

 

So I take it you use cooking oil then?

Remember a twin turbo produces a lot of localised heat, which degrades the oil quicker and can easily result in blown turbos. Fully synth oil may be overkill for a 3k oil change (because it's designed to last longer, but it will also lubricate (perform) better.

 

Also, short trips in winter put a much greater stress on engine oils, and 3-litre engine takes a while to reach full temp. Before the engine fully warms up, water and gases like SOx, NOx create acids which oxidise (breakdown/age) the oil.

 

This is why I try and change the oil late autumn and early spring.

 

But like someone said above, oil is a lot cheaper than an engine rebuild ! Insufficient oil changing results in more wear, poorer fuel economy, less power, inefficient cooling and possibly blockages due to build-up of crud.

 

You would probably be better using a semi-synth every 3k than a fully synth every 10k. But this is a guess simply to make a point. Oil quality is important, but frequent changing is arguably more important in a twin turbo.

 

The 'problem' is that oils are generally only designed for long ODI's (oil drain intervals) in everyday cars, and this is why high quality base oils are used, and high additive treat rates. It would be better to use custom-designed oils with fewer additives and quality basestocks - then changing it more regularly would be more cost-effective and make better financial sense, as the oils could be made cheaper, but alas, I know of no such oil :(

 

Check out this link...

 

http://www.howstuffworks.com/question164.htm

Thanks fellas.

 

I will continue to change the oil as before and certainly will also change it more often than specified in the new car, but at least I have a bit more info than I had before which was the old adage that it is cheaper to change the oil than the turbos and engine.

 

Anyway at just over £20 at Costco Mobil 1 still won't break the bank.

Do they do mobil 1 motorsport at costco now?? (15w50)

cos last time I saw it was 0w40???

 

regards

A lot will depend on who's oil you use.

The only way to really tell is to get a proper chemical analysis done on the oil to determine it's condition, but who's going to do that.

 

Alot of it is piece of mind. I would say that 6k mine would be fine with fully synth. No harm in changing it sooner, only to your wallet.

Alot of the new synths recommend anything up to 25k miles or once a year depending in the type of driving.

IMHO you cannot change oil 'too frequently'...3,000 seems to be about right, but more frequently certainly wouldn't hurt...apart from in the pocket!.

 

I read an article recently about a guy in the States who runs a Volvo PS1800 (for those of you old enough...thats like the one Roger Moore used as 'The Saint'). Well...he'd just completed his TWO MILLIONTH mile in it....and yes, it has the original engine.

 

His only advice....yep, you guessed it....change the oil every 3,000 miles!

Originally posted by M3Pilot

Alot of the new synths recommend anything up to 25k miles or once a year depending in the type of driving.

 

No way would 25k be OK for a 300ZX - it would even be pushing it for a normal, small engined non-turbo car imho. A twin turbo puts a lot of stress on an oil, especially when driven hard. Recommended oil changes are at least TWICE as often as a non-turbo and most non-turbo's are about 10k !!

 

The car manufacturers boast longer ODI (oil drain intervals) NOT for the health of the car, but to sell them. They want you to buy a new one in a few years.;)