Engine oil Grade

Technical Area Routine Servicing
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  1. My model of MX-5 is: _2016 1.5 ND SEL
  2. I’m based near: NI_
  3. I’m looking for technical help or recommendations on: Oil grade

We have a 2016 Mazda 1.5 MX5 ND and a 2017 2.0 Mazda 3 Sportnav. In recent years I have specifically insisted on Mazda Supra 0W-20 at the service for both cars.
A local Mazda dealership recently said Mazda recommend Mazda Ultra 5W-30 for the Mazda 3.
From the User manual either are recommended and rightly or wrongly I believe that the 0W-20 is preferred.
Obviously no harm in using either, but what are the advantages of one over the other?
Should I continue to insist on the more expensive Supra 0w-20 for both cars?

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The sae rating is for hot and cold testing and how many drops of oil you measure. Don’t ask me how its done i can’t remember

For cold test its the first number and smaller is better
0w is better than 5w
5w is better than 10w

For hot test is the second number and bigger is better
30 is better than 20
40 is better than 30

Fully synthetic oil means it doesn’t degrade as easy as semi synthetic.

My recommendation is to open the manual and read whats recommended for your car and the ambient operating temperature you live.

I use mobil 1 fully synthetic 0w 40 in my cars (but thats my own choice and do it on my own risk)

Last thing… never skimp on oil or oil changes. Its what keeps your car alive

2 Likes
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Sorry to bring up an old topic .I have been advised by my garage that Castrol Edge 5w30 M is what they will use for my oil change in my 2.0Litre ND. I see that Castrol Edge M is C3 and not an A5 but is classed as SN oil will this be OK. There are so many different oils and specifications now ! The car manual does say A5/B5 or SN oil. Thanks in advance.

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The C3 oil is for direct injection engines (which the ND is) so will be fine.

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ACEA Spec C3 relates to Petrol and light duty diesel engines, based on A5/B5 mid SAPS (Sulpadated ash, Phosphorus and Sulphur), two way catalyst compatible. Higher performance levels due to higher HTHS (High temp high shear) for better wear protection

Just read this somewhere so don’t ask me what it all means, but I believe good to go for the ND.

My nearest Mazda dealership was actually the main dealer for Vauxhall in another town and used Vauxhall oil (C3) in my ND for the first 3 warranty years of its life.

Personally prefer to use Mazda oils so have used an independent garage and more lately another (further away ) Mazda dealership to get Mazda Oil

Prefer the more expensive Supra 0W-20 to the Ultra 5W-30 for the lower viscosity for cold temperature/cold start performance

Looks like the Castrol oil your garage intends to use is just fine

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Many thanks for the information .

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That’s great thank you for you reply.

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There are higher quality engine oils you can you rather than the Mazda oils. For cold start performance you could use a C3 0w/30 which will also give better protection when hot. 0w/20 is after all just used for better fuel economy as opposed to protection when hot.