Oil change Navara np300 from 5W40 to 15W40

[Araxxus]

Greetings everyone, I hope everyone's doing good. I have a question hopefully someone can give me some advice. I have a nissan navara np300 2017 that just reached 100K Km, I've been using Motul's 8100 X-CESS 5W40 full synthetic since the beggining (0 Km), my question is:

¿Should I change to a more economic oil like to Motul 15W40 Mega X or should I stick with the Synthetic one?

I currently use the Motul Mega X on my Mazda BT-50 2013 and never had any issues with it, in fact, at the beginning I was using Castrol "magnatec" and it was literally killing the engine and when I changed it to Motul it made a huge difference, in performance and diesel consumption. Going back to the navara, the reason I used synthetic oil from the beginning was because the engine was relatively new and I didn't want to risk using a standard oil on it.

 

[CTL]

No idea how you could tell a different oil (if both oils were the same grade) made a “huge” difference. Even if you also changed grades, a “huge” difference in performance seems unlikely.
Why are you using a 5W40 in Guatemala? That is an oil grade for cold climates.

 

[Araxxus]

No idea how you could tell a different oil (if both oils were the same grade) made a “huge” difference. Even if you also changed grades, a “huge” difference in performance seems unlikely.
Why are you using a 5W40 in Guatemala? That is an oil grade for cold climates.

The nissan came from fabric with a 5W40 ford motor oil full synthetic, seemed natural to just stick to the same grade.

 

[Lost1?]

I use 10W40 to cover temps from 0 to 45C. Stick with the synthetic on modern engines

 

[Araxxus]

I use 10W40 to cover temps from 0 to 45C. Stick with the synthetic on modern engines

Will do, thank you for the advice, Unfortunately we don't have a lot of options when it comes to synthetic oils.

 

[shanegtr]

I'm not all that familar with Motul oil's. From my reading of the specs the Mega X is a heavy duty fleet oil so there's a good chance that it will be a quality oil for the price, but the 8100 will be a superior oil all day of the week.
The lower winter grade (5w vs 15w) will be of limited difference as that really only plays a part in cold starting - when its warmer they will both pump fine. The 5w is obviously better when its colder but they are both SAE40 so will be in the same viscosity range at operating temp. 8100 has a higher viscosity index which means its viscosity will be more stable over temperature changes