- My model of MX-5 is: __3
- I’m based near: __Colchester
- I’m looking for technical help or recommendations on: __oil
My 5 is due for its oil and filter change, I did it last year and I used Castrol 3000 5w30 as advised along with an MX5 filter.
My question is, there’s a lot of 5w30 Fully Synth oils available and a lot cheaper, is using one of these going to cause a problem?, now before I get my head bitten off, I will almost certainly be using the same oil and filter again, but wondered why other oils are frowned upon, is it the lack of additives etc, or purely the quality? for instance there is 5 ltrs of Ford 5w30 fully synth oil on ebay for ten pounds less than the Castrol 3000.
My eldest son has just purchased a MK2.5 and wants service it himself also, we are no mechanics ,so I am interested to know what people think .
You’ll get a good deal of opinion, what’s best, this is what I use etc.
I’m no expert so I can’t really comment only…
I use Mobil super 3000 5w 30 FE full synthetic. The FE bit means (on the container) it’s suitable for Ford engines, I don’t think that matters too much. What does matter is what spec it says in the handbook, or ask here, after all we try and use the best or suitable products.
I could use it in my VAG engine daily driver also as that recommends a 5w 30 oil too but I use a Castrol oil for that purely as again it matches on the container what is recommended in the handbook.
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OK thanks, to be honest I haven’t really looked through the handbook, and like a lot of blokes I rarely read instructions either, I’ll check it out, what I know about oil is from word of mouth.
I’m just curious as in the past on other old cars, I have used any oil available as long as the grade was ok, but want to make sure the Mazda always has decent oil.
Try Fuchs
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Most engine oil manufacturers have and oil recommendation tool on their website where you just enter your reg number and it tells you what oil to use.
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One thing to be aware of is that the Mk3 uses just over 4 litres so it is far cheaper to buy an oil that comes in 5 litres rather than a 4 litre plus 1 litre. For this reason and the fact it fully meets the Mazda spec I use Mobil 3000 FE.
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I think, but stand to be corrected, that the FE designation stands for ‘fuel economy’ meaning that oil has passed a test of some sort, or it’s just thinner than something else, ie 10w40 for example.
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You are correct on the FE on the Mobil oil. I didn’t know, now do as it’s been explained to me by someone who knows about these oils.
Anyways, I’ve used it for around 8 years this current NC and the previous one have been great, hardly any oil usage between changes but I do change at around 5k miles each time.
I looked it up, and FE stands for Fuel Efficiency/Fuel Efficient - probably just some marketing blurb, although I understand that thicker oil, as well as offering better protection at high temperatures, will use marginally more power to pump it around the engine.
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I use Comma oil , they have a great web site , you just put your reg in and it gives you the oils to use in the engine , gearbox, diff and the type of coolant eg Colour you should use in your car .
5w30 fully synth does not describe the oil in enough detail for a modern engine with long service intervals, you need to at least consider the required ACEA rating too.
In some cases there is a vehicle manufacturer specification that should be adhered too, for example VW’s 1.9 TDI needed VAG 506.01, 505.01 or 507 spec oil otherwise the injectors could wear prematurely. Not paying attention to that maybe you get lucky and there’s no problems, but maybe you accidentally get a non-low SAPS oil and expensively ■■■■■■ the DPF.
In case of my ND 2.0, Mazda state 0W-20 A5/C5 and 5W-30 A3/C3 oil. They don’t seem to have a particular manufacture specification they insist on beyond that.
As above, plenty of online utilities to tell you the correct oil.
I would be careful ordering oil online, plenty fake products out there, so buy only from know suppliers.
Remember Halfords give club members 10% off, so it is usually easy to get a quality 5l tub of oil from them that suits your car for under £30.
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I nearly fell into that trap with buying
a cheaper Castrol transmission oil on eBay. Checked the specs and it doesn’t match what I wanted, Opie oils are delivering the correct one but a little more £’s this week to me.
Carparts4less also helpful.
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Not sure how lubrication oil would affect injectors in a 4 stroke petrol engine
I used the VW Pumpe Duse as example I have personal experience of to show that “5w30” doesn’t describe engine oil in enough detail these days. The latest petrol engines have GPF, DI, sensors that monitor oil and exhaust gases, so dismiss my examples at your own risk.
I didn’t realise how complex engine oils had become, in the "old days " if my car took for arguments sake 10w40 oil, then it was off to the garage, and whatever bargain 10w40 oil was available, thats what went in the car, including my old Spitfire that was suprisingly robust , but really didn’t like wet roundabouts, but that’s another story.
But the MX5 deserves the fuss, so the right oil is obviously important, and this will also be passed on to my eldest son, who won’t stop looking at his newly acquired MK2.5 after he’s parked it up 
Huge advances in oil technology, allied to much better production tolerances, especially over the last 40 years or so are the main reasons most automotive IC engines are good for 200k miles without significant wear, - as long as the oil and filter are changed every 10k miles or annually.
50 years ago most engines were worn out by 100k miles, and often needed a decoke /valve guides/rings/bearings at half this.
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Just to make it harder for you ACEA have changed their categories twice since the ND was launched. My advise is not to be tight-fisted and buy a high quality recognised brand. Visit their website, enter your number plate and see what they recommend.
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I suggest that if you take your car of any make for a service you confirm they use the exact oil that the manufacturer recommends. Many places buy oil in bulk and that’s what they use……