Help With Oil Choice: Mazda MX6 2.5 V6 (In South Africa)

[Xenithon]

Hi All. First time poster here. I am not the most clued up on oil but know a decent amount of background info.

I have a Mazda MX6 2.5 V6 manual. It has 140000km on the clock (roughly 88000 miles). I have been using generic oil (20W50 as suggested by Mazda dealers here) but would like to change to a higher quality synthetic oil.

I have read up a lot on the MX6 forums and what seems to be highly recommended is Amsoil, Royal Purple and Mobil 1. RP is prohibitively expensive here, and M1 is not readily available (sometime they have stock, often not). Amsoil I did not think I could get but found a supplier here at reasonable prices.

My two main questions are:
1. which oil to go for. Other than the Amsoil which I mentioned, I can also get: Shell Helix, Castrol GTX/Magnated and the new Castrol Edge, Caltex Halvoline, Petronas Syntium.
2. which weight should I look for? The Mazda dealers suggest 20W50, the MX6 forums and handbook suggest 5W30.

In South Africa (JHB, quite high above sea level) it is relatively hot. Temps average 25-30 in summer, 15-20 in winter. Minimum temps hardly go below 5 (and that's dead of night only).

What I was thinking was using the Amsoil 10W40. Would that be a good choice? I fear that 5W30/5W40 may be too thin perhaps?

X

 

[haley10]

You've come to the right place. We have some great Amsoil sponsors here. I'm sure they will be along shortly with some good recommendations.

 

[Xenithon]

Hope so

The main problem though is the limited availability here in South Africa. Even if a brand is brought in, the entire range may not be available - only a small selection - and very often distributors come and go so supply is not reliable.

 

[Pablo]

I don't really recommend the 10W-40 (I assume you are talking full synthetic, not XL). Nothing wrong with it, per se, it's just not the best Amsoil motor oil.

I would say better would be:
5W-40 Euro Oil
or
Series 2000 20W-50
or
15W-40 HDEO (AME)

Can you get any of these?

 

[haley10]

Yea, that happened to some our UK members. It was available through Demon Tweeks in Wales and then they stopped distributing it.

I though you guys were fortunate enough to get Castrol SLX?? It's listed on their web-site. One of the best out there if you can get it.

 

[Xenithon]

Hi There,

I can get the 5W40 yes, but assumed that 5WXX would be too thin for the climate here. It is fairly hot and dry. Isn't 5WXX and 0WXX more for colder climates such as the UK and northern Europe?

I can also get the Petronas Syntium, 5W40 being the only one available. I can get the AME but isn't that a marine/diesel oil?

X

 

[Xenithon]

quote:

---

I though you guys were fortunate enough to get Castrol SLX?? It's listed on their web-site. One of the best out there if you can get it.

---

Can't get SLX here as far as I know. I can get the GTX, Magnatec and Futron, as well as the pricey RS. The Castrol Edge is also meant to be available soon but unsure about supply reliability.

 

[Pablo]

Sure a 5W or 0W will flow better in cold, but this does not mean it will be worse in hot weather. You need to read a bit. The second number is the viscosity at 100°C.

What exactly does the printed manual call for, anyway?

AME is a HDEO, with dual rating for gasoline and works fine in gas engines - I assume you aren't burning oil or anything.

 

[Xenithon]

Nope, not burning oil. A lot of the mechanics here though say it may be too thin and thus increase oil burn and leaking, especially since it is a fairly high mileage engine. Any truth to that?

According to this MX6/Probe 'bible' they say that:

"For the UK, 5w30 or 10w30 are recommended oils, with 5w30 oil getting to the HLAs & 4 cams much quicker on start-up. Mazda themselves recommend 5w30 oil if HLAs are noisy."

That is for the UK where temps are a lot colder and it is close to sea level.

 

[Xenithon]

Oh and just to add, the guys who work on the cars here suggest a 20W50 oil.

Here is a listing of the Amsoil products I can get here.

 

[haley10]

quote:

---

Originally posted by Xenithon:


I can get the 5W40 yes, but assumed that 5WXX would be too thin for the climate here. It is fairly hot and dry. Isn't 5WXX and 0WXX more for colder climates such as the UK and northern Europe?

---

No! The lower 0w/5w only relates to low temperature pumpability. A 5w40 is still 40wt. at operating temperature.

I run Castrol SLX 0w-30 year 'round myself. It is a thicker 30wt. at 100°C, the fact that it is 0w is just an added benefit if needed.

 

[Xenithon]

Ok. So which would you suggest I go for? One of the Amsoil's as listed in the link (5W30 or 5W40)?

Or is one of the cheaper ones sufficient such as the Castrol's or Shell Helix?

 

[Pablo]

I think the Amsoil 5W-40 will be best.

There may be some crazy old wisdom in trying the S2K 20W-50. (which is not as "thick" at RT vs. a dino 20W-50)

 

[haley10]

quote:

---

Originally posted by Xenithon:
Oh and just to add, the guys who work on the cars here suggest a 20W50 oil.

Here is a listing of the Amsoil products I can get here.

---

Old school thinking with 20w50. 88K miles is nothing. All 20w50 is doing is getting you reduced fuel economy. The 5w30 ASL or 10w30 ATM would be my preference. Yea, I know it gets hot there.

Castrol RS is some good stuff, too.

 

[Xenithon]

Hi There,

Sorry for the mixup, as you can see in that link I posted, a 5W40 is not available. These are the ones which seem to be the most likely candidates:
- 5W30 Synthetic Oil
- 15W40 AME Diesel Oil
- 10W40 Synthetic Oil
- 20W50 Synthetic Oil

 

[haley10]

quote:

---

Originally posted by Xenithon:
Nope, not burning oil. A lot of the mechanics here though say it may be too thin and thus increase oil burn and leaking, especially since it is a fairly high mileage engine. Any truth to that?

According to this MX6/Probe 'bible' they say that:

"For the UK, 5w30 or 10w30 are recommended oils, with 5w30 oil getting to the HLAs & 4 cams much quicker on start-up. Mazda themselves recommend 5w30 oil if HLAs are noisy."

That is for the UK where temps are a lot colder and it is close to sea level.

---

Mechanics often don't understand all they know about lubrication. I don't think the temps in the UK or elevation is relevant. Very minor points from your engine's perspective.

 

[Dad2leia]

Xenithon, what viscosity is that Castrol RS that you speak of?

 

[Xenithon]

When I contacted the local Amsoil distributor (who is meant to be fairly knowledgable) he said the following:

"When you ask your local Mazda dealers they would recommend a 20W50 for South African conditions and the fact that the car has done 140000 km emphasizes the suitability of a thicker oil as the clearances are bigger now."

 

[Xenithon]

Dad2leia - it is a 10W60. It is very expensive though. Here are the details.

 

[Dad2leia]

Knowing how I drive my vehicle, I've often wanted to try this stuff, just to see how it would do, but then considering right now we are entering the cold phase, and the car is still "under warranty" 'till 160000 Km, I'm a little leary about putting something in with such a high cSt number to start with.

My two cents for you is use the Amsoil 15w40 AME, enjoy the extra additive package and detergency, and relax with the fewer amount of times you'll have to crawl down under and get dirty.