Which engine oil do you use

[jules]

I didn't realise Magnatec was semi-synthetic?

Jules

[bensale]

Yep, the 10w40 Magnatec is a semi synthetic oil.

I always liked it, though the car has run better since putting the fully synthetic Elf in it which I luckily pay wholesale price for (works out about the same as magnatec). I would be much less likely to buy it at retail...
I use Peak 20w50 mineral oil in the Alfa, good oil, made in Melbourne (Dandenong) which is nice. Stupidly cheap wholesale and retail prices too.

[Mr Morlock]

if you ring say Castrol tell them what car you have and ask them for a recommendation will you take the advice? Ben's comments are interesting - his car at 230000 is good testament to the MX5 and yes we know many have done even more. But "you" guys are fussy- you change the oil and filter regularly. But what about the previous owner(s) of the car- multiple owners and no records is common and changing say to a full synthetic at the latter end of its life is good or not?

[jules]

It's an interesting argument you make Mr. Morlock.

I could probably buy Coles or Woolies oil for about $15 and dump it in the car every 20,000kms. This would be quite a saving on the guys putting in Synthetic Oil every 5000kms that costs anywhere up to $60-70.

With the savings I make before then engine finally dies, I reckon I could easily pay for a replacement low km engine $600, and drop it in myself or maybe pay another $450 to have a grease monkey do it (Qld mechanics are reasonable). I would probably have a fair bit of change left over as well.

However, due to the fact I am an anal and fussy bugger when it comes to Malibu, I will be buying Magnatec in 5000kms time as usual


Jules

[bruce]

I kind of think that synthetic oils make no difference in a normal run of the mill motor. It just seems a lot of money, especially when people change it at 5000 kays.
If your motor is turbo'd etc, synthetics MAY be beneficial, but that is only a guess.
Also considering the period we keep our cars, we've probably sold them on before any problems occur.
Even if we held them forever, as said above, you'd pop in a new motor with all the money you've saved buying conventional oils eg. $30 price diff between basic oil and synthetic, 5000 kay changes, spread out over say 250,000 kay life = saving of $1500.

[bensale]

Yes if you change out every 5000 kms on a car used for 100% road use it does not make financial sense. However, if you use the extended useful life you get from the synthetic oils it makes better sense. As i've noted my engine felt better and more responsive ( although not nessesarily performed better) after changing to synthetic oils.

[bruce]

Yup, I would change synthetics in a road car at 10,000 kays (notwithstanding a track day or two).

[mitch_f1]

so with regular track days (1 or 2 a month) how often do those peopl change their oil??

This is a good conversation by the way; many interesting points are being raised

[GP]

Synthetic oil may have a long life before it breaks down but contamination of the oil with petrol, water, etc.is the same no matter what you use. In other words I wouldn't go 10000 between changes

[bruce]

BMW recommend an oil change every 12,500 kays (they used to recommend Mobil1). I doubt their tolerances or efficiencies are that much better than Mazda.

[GP]

Probably has a more advanced filtration system.

[Agent Orange]

The question as to synthetic oil having a detrimental effect on seals , I do not beleive this is so.
I service plenty of mx5's most have high kilometers and many already display a smear from the crank seal , a film at the rear main, the occasional drop from the crank sensor seal and a propensity to leak from rocker covers. The fact is by 100000 to 20000k the seals are tied and due for replacement anyway.
Not withstanding this I have used mobil 1 ow-40 or 5w50 in plenty of mx5's that have been on mineral oils [ inc my own ] and have not seen any increase in seal leakage on any of the cars from the use of synthetics [ myth busted]
The Mobil oil bible lists Mobil 1 as a prefered oil for mx5 right through the model range [ after all it is a reasonably high tech / high reving/ late style engine , not something out of a tractor]
There are direct benefits for using good synthetic oils of any brand , my car since the swap - no tappet rattle cold , a slight gain in horsepower and on removal of the rocker cover [ timing belt due / new tensioner idler and crank and cam seals - shear madness not to do them as a set] the engine is spotless , no sludge , no fluff, no hard oil carbon deposits ]
To me oil is the cheapest item you put for the car , so no compromise, I spend more on polish, petrol, tyres , rego and insurance.
I bet none of you fit retreads, use budget brake pads, look for the cheapest polish or would fit a penny pinching repalcement exhaust.
I love my " baby" I might buy the wife cheap perfume , but never will I buy the car cheap oil .
I change the oil every 8000 to 10000 k depending on how much track work the car puts in
last point - it dont have to Mobil , but buy synthetic
Agent Orange

[jules]

Great post. Thank you.

Jules

[bruce]

Probably has a more advanced filtration system.

Yeah, it's called an oil filter.

[GP]

The Mobil oil bible lists Mobil 1 as a prefered oil for mx5 right through the model range

Would they say anything else.