Can I use this oil in my car?

Will · 24 Mar 2014 at 19:58

One of my dads friends has had to stop driving for medical reasons, and has sold his car. He has since given my dad a load of oil he was planning to use for a service and said it would be good for my car, 'its 5w30 and thats what Mazdas take'.

The oil I now have been given 5l of is Castrol Edge FST 5w30. I know this is good but not entirely sure whether its suitable...he had a VW Golf.

The car is a 2008 Mazda MX-5 2.0 Sport, this has a Mazda MZR engine which is very very very similar (nearly identical) to the Ford Duratec.

Now normally I just read the specs of the oil, compare to the handbook and go with that. The handbook for the car does not say much, no Mazda specific specs, it just says I need a 5w30 oil that meets API SL and ACEA A3/A5.

Quick look says the Castrol Edge 5w30 meets API SL, so I thought it'd be fine, but then I see its but is ACEA C3, so slightly different. It also meets loads of other new manufacturer specs, but no mention of anything for Mazda.

Will this be fine to use in my next service in my MX5, or am I best using something else?

malfunkshun · 24 Mar 2014 at 20:04

I believe 5w30 is correct for that engine, but there are a couple of MX-5 drivers on here who would be more informed than me.

Hawk Tuah · 24 Mar 2014 at 20:29

I think you are over thinking this. Handbook says 5w30. It's 5w30. It'll be fine.

Will · 24 Mar 2014 at 20:46

I figured it should be okay...but can flog it on if its not really suitable. £40 odd worth of oil...

Clarkey · 24 Mar 2014 at 20:47

I would use it. Isn't 5w30 a bit thin for a properly driven sports car though?

rjk · 24 Mar 2014 at 20:50

Speak to Simon on here tbh.

bazzabear · 24 Mar 2014 at 20:52

As above, not sure you need to look much further than it being 5w30, if that's what your car requires.

Will · 24 Mar 2014 at 20:52

Properly driven, Clarkey you over-estimate me

.

5w30 seems the norm for almost all Duratec/MZR cars from what I've seen, only the yanks seem to vary away from this and we know what they are like with obscure oils changed every 33 seconds....

As for the grade being all the matters...maybe, theres so many additives and weird oil specs now, stuff for DPF cars, direct injection and all this. Obviously not necessary for my relatively simple engine, but dont want to use something if theres a better option.

And Rich I figured Simon is the man in the know and could give a straight answer...hope he sees this

Simon · 24 Mar 2014 at 21:43

Will be fine.

Longer answer: These engines are Ford so have the universal 5W-30 2.9 HTHS ACEA A5/B5 recommendation that Ford use in everything. Usually they also ask for the Ford 913C spec too, if this isn't in the handbook then I wouldnt worry too much

Technically ACEA C3 offers identical performance in terms of engine tests required but as its a 3.5cP HTHS oil is will have better durability and worse fuel economy.

Whats the drain interval on the Mazda? 12.5k miles? The starting TBN of the A5 oils will be over 8, Magnatec A1 5W-30 is about 10.5. The EDGE 5W-30 FST is a 6 TBN oil due to the 504 507 specification which is primarly for diesel engines (DPF test limits the amount of ash/TBN).

Will · 24 Mar 2014 at 21:48

Thanks

Drain interval is 12.5k I believe. I do very low mileage though, approx 4-5k/year, still get it changed yearly as part of a service though, partly as I do lots of short journeys around town.