0W 40 ok for nb8a?

irwin83r · Postby **irwin83r** » Mon Jul 31, 2006 7:08 pm

hello all

just about to start an oil change an realised i bought a different wieght to what i was previously told to use.

i have bought castrol's edge 0w 40 usualy use 5w 30

will the 0w 40 be ok or should i go back and get something else?

what you all use?

irwin83r · Postby **irwin83r** » Mon Jul 31, 2006 7:26 pm

well.. castrol seem to think its fine going by their web site..
so in it goes :shock:

its in writing so if something goes bang they can pay for it

tk421 · Postby **tk421** » Mon Jul 31, 2006 10:23 pm

My mechanic told me that 0w40 was the go for my next service when I turned with 5w50 mobil 1 last time. He's a very experienced former MX5er (Jason from Top tune Nth syd). As long as your tappets aren't noisy you should be fine.

Steve

irwin83r · Postby **irwin83r** » Tue Aug 01, 2006 12:05 am

and what if my tappets are noisy :shock:

tk421 · Postby **tk421** » Tue Aug 01, 2006 1:17 am

Thinking about it you are lowering the lower number compared to the 5w30 so they may in fact be quieter at start up and about the same or a little quieter when hot as your raising the higher number (sorry about that didn't notice the higher number was going up)

I have used 0w 30 in mine before and found the tappets too noisy at the time. I have had them set by the rev doctor in hornsby since then so the prob is cured now.

Steve

irwin83r · Postby **irwin83r** » Tue Aug 01, 2006 1:19 am

ah, that makes more sense

should be good then mine are a little clicky at times but nothing major... too much exhaust noise to worry about that :shock:

hoping to fix that soon also

Garry · Postby **Garry** » Tue Aug 01, 2006 9:27 am

Mazda use and recomend 10W40 in NA/NB's. I have no idea about NC's.

Inf3ct0R · Postby **Inf3ct0R** » Tue Aug 01, 2006 9:52 am

I have been using 0w-40 formula R castrol for over 1.5 years, and its still running

*typo*

Garry · Postby **Garry** » Tue Aug 01, 2006 10:06 am

I have been using 0w-40 formula R castrol for over 1.5 years, and the is still running

That says a lot. I've seen how you drive. :shock:

1.5yrs of your driving is equivalent to 5yrs normal driving.

Inf3ct0R · Postby **Inf3ct0R** » Tue Aug 01, 2006 10:29 am

Garry wrote:
I have been using 0w-40 formula R castrol for over 1.5 years, and the is still running

That says a lot. I've seen how you drive. 1.5yrs of your driving is equivalent to 5yrs normal driving.

yup yup, been to the track over 15 times? motorkhana 20 times?

of course you should only drive the car hard when its in its operating temperature

irwin83r · Postby **irwin83r** » Tue Aug 01, 2006 5:27 pm

cool bananas

Inf3ct0R · Postby **Inf3ct0R** » Wed Aug 02, 2006 10:10 am

Chris P wrote:If Mazda recommends a weighting of 10W....that means that the oil pump is used to the resistance of pumping 10W oil?

If its thinner say 5W or 0W will that lead to the oil pump breaking down, not in the immediate future but say years down the track?

in the manual it states that 5w-30 is ok as well... furthermore, 5w from mobil and 5w from castrol will not be the same...

irwin83r · Postby **irwin83r** » Wed Aug 02, 2006 10:43 pm

cant imagin the pump being under less load at cold being a real problem..
the only thing that might cause bother is if this meant the pump could go faster due to the less resistance and it burnt its self out some how.. but that sounds a little unlikly.

Garry · Postby **Garry** » Thu Aug 03, 2006 10:09 am

It's a positive displacement pump dríven from the engine. It can only go as fast as the engine will let it. I dont think you'll burn it out by spinning it to fast with thin oil. :mrgreen:

You may end up with sligtly lower oil pressure when cold and more oil may drain back into the sump when the engine is cold due to the thinner oil. But then the oil should move through the engine faster when you cold start the engine. So there's advantages and disadvantages. It's in the accepted range in Mazda's oil recomendations sheet in the owners manual so I doubt you would have any problems.