Castrol NZ recomending 10w-40 over 5w-30 ???

[SXE10]

As per most oil manufacturers these days Castrol NZ have lube guide on their web site as well as a SMS text service. You put your rego plate in & it recommends oils for you. I thought I give it a go & it came back with Magnatec 10w-40 for my car?? I was horrified (I'm not a fan of 10w-40 semi) the factory spec is 5w-30/10w-30 for the 3SGE. I emailed their technical team to ask them why & this is the basic response I got
Quote:
As he mentioned from the chart that you sent through, the ambients in NZ are higher which is why we recommend a Magnatec 10W-40 over the EDGE 5W-30. Using the EDGE product over the Magnatec is not incorrect and you shouldn’t experience any problems by using this, it is just not our primary recommendation for your vehicles.

Here's the page from my owners manual.

I don't understand how they think a GII 10w-40 with a VI of 151 is going to protect better than a GIII 5w-30 with a VI of 165. Not to mention the Magnatec has a KV @ 100°C of 14.4 over the Edge's 12 which puts additional drag on the engine & VVTi system.
I did try Edge 0w-40 last summer & it was way too thick & made the engine really sluggish.

 

[chubbs1]

I would continue to use the 5w30. As it said you won't be harming the engine but like you, I have no clue why they would spec 10w40 for your engine. Just seems like overkill.

 

[Shannow]

Go through Castrol's website and try to find ANY car that they don't spec magnatec 10W-40 for.

 

[SXE10]

Do you reckon that's because they have such a limited retail range down under & don't want to scare off potential customers with the price of Edge? We don't even get Magnatec 5w-30 like you do in Oz. Their range consists of GTX 15w-40, 20w-50, Magnatec 10w-40 & Edge 5w-30, 0w-40, 10w-60, 25w-50 in NZ.
Oh well I just put some Mobil1 5w-30 in this round, Castrol wont be getting any more of my money (not unless I can get Edge for under $9 per L again like I did at my previous job).

 

[Shannow]

I don't think it's limited range, as you say, they've got heaps of stuff that they could be quite specific with.

Mobil on their product selector usually start with the appropriate mobil 1 oil/viscosity, then downspec from there, and Castrol could do the same.

I think magnatec 10W-40 has their "economies of scale" measure, and they are sort of doing a bulk sale push to keep that as their earner.

 

[supercity]

Originally Posted By: Shannow


I think magnatec 10W-40 has their "economies of scale" measure, and they are sort of doing a bulk sale push to keep that as their earner.


I believe this to be true. The owners manual seems to be the last thing people adhere to in this part of the world and the oil manufacturers know it. They recommend what they want to sell; to suit their sales targets. I was talking to a ex-Castrol rep about this. They do recommend what they think they can sell the most of to that market. If Castrol recommend a $30 oil over a $70 oil, they are more likley to get the sales. On a more expensive car, they are more likley to sell the more expensive oil easier, so they may recommend it.

It's the same with my Toyota Rav4. 5w30 is printed on the oil cap but it's usually the last grade recommend as it's quite an expensive option. 15w40 is always high on the list.